# Tight Bushings = Harshness



## digev (Mar 7, 2019)

Do you think your fork feels harsh over small bumps?

Chances are your fork lowers may have tight bushings, which is quite common! Especially on brand new forks.

I knew mines were not great ... I had to apply way too much force and wiggle the stanchions almost all the way to make the uppers slide into the lowers while servicing the fork. How could they be great at dampening small vibrations that don't generate enough force?? Once I realised that ... I ordered a tool to resize them.

Fork Bushing Sizing Tool










Once received I measured the "head" on the tool to use with 35mm stanchions at 35.1mm.










Fox say correct bushing tolerance is a diametric clearance of

min: 0.0015" (0.0381 mm)
max: 0.0090" (0.2286 mm)

source: https://www.ridefox.com/fox_tech_center/owners_manuals/07/eng/bushing_technology_and_inspection.htm

That +0.1mm (0.003937") to resize/widen the bushings is perfect.

If you do the math and take Fox's recommandation to see what the result should be, you get:

(0.0090"-0.0015")/2 = 0,00375" (0.95mm)

Which is right in the middle!

RS doesn't even list the bushings on their "Spare Parts Catalog" because they are made to last forever (basically if the fork is well maintained, you won't have to worry about it), so I guess they make them a bit tighter now to backup that claim

Truth is, most of the time they are too tight and when people scratch their head and try to improve small bump compliance by tweaking x or y they miss the main culprit (tight bushings), it generates a ton of frictions and from there it's an uphill battle.

Do a test next time you service your fork.

1 - Drop the lowers
2 - Remove the damper/spring
3 - Remove the seals
4 - Cycle the uppers into the lowers by hand (with nothing else)

You'll be surprised (or shocked. LOL) by how much force you need to cycle the uppers ... I can almost guarantee they won't fall down like mine! If it's the case then your bushings are too tight/narrow.










Out of 3 forks I serviced recently (Pike/Lyrik/Yari), including my own they were all sticky and hard to cycle, you had to slightly move the uppers side to side to push them down ... and apply force at the same time!

Once I resized the bushings, well ... have a look at the gif, the uppers now drop under their own weigh into the lowers.

It's very easy to use the tool, just force it through the bushings with a twisting motion and you'll have perfectly honed out bushings in your fork. (apply some Motorex Supergliss on the head and on the bushings with a long paint brush before)

If you want to do it, you've got 3 options.

1) - Make it done by a proper suspension specialist/tuner (it's nice to do it when you need servicing or tuning)
2) - You could buy the Fox tool for about $1000, yeah you read that right (ref: 803-00-813), that includes all the diameters they make (32/34/36/40)
3) - Or you could ask Oliver at Blue Liquid Labs | An Oliver Majewski Project to make you one for 140USD with any head diameter you want/need (that's what I did)

And don't forget to lube them with a nice slippery oil such as the Motorex Supergliss 100k (Big thanks to Dougal for testing and releasing that info)










Resizing your bushes will give you slick, super smooth, stiction free action ... IMO that's the number 1 thing to verify and correct if necessary before modifying anything else. You can definitely feel the difference over small bumps and chatter it's incredibly supple off the top now.

because the fork doesn't need a lot of force to start moving/reacting and make those stanchions slide (they are not micro-stuck like before). it's a bit like when you have seized bearings on your frame, because of the weight/leverage AND it probably happened over a long period of time you can't really tell ... until you swap them for fresh ones and all of a sudden it feels like a brand new bike and your shock can do it's job to dampen small vibrations and chatter, NOW you can feel it ... well it's the same feel 

I hope it will be helpful for some of you!

Some comments about tight bushings ...

TF-TUNED (MTB suspension tuners in the UK) say:



> They simply won't "bed in" as is commonly believed & the bushes need re-sizing. This process involves changing the shape of the bush within the lower leg, to fit the stanchions better and prevent binding when the leg is passed through.


source: https://www.tftuned.com/tech-help/22-rockshox

Fox about Race Prepping a Fox 40



> With the stanchion carefully set aside, Kolja does one of the things that he says makes the biggest difference to the feel of the fork-he works the bushings. With mass manufacturing the tolerances for the bushings is tight, opening the bushings does have an effect on the life of the fork, which would mean the fork would need servicing much sooner. By opening the bushing the fork moves more freely in its travel.


Source: https://www.pinkbike.com/news/race-prepping-a-fox-40.html


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## digev (Mar 7, 2019)

When you buy the Fox «FORK BUSHING SIZING TOOL ASSY» you get two cylinders/heads (sorry I don't know how it's called) of almost the same size.

For example you get a 36.0mm and a 36.1mm

Do you know why?!

Is that even the real diameter? It's just how I understand it.

https://www.velomanija.lt/application/images/Image/prekes/FOX/803-00-813.jpg


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## Dougal (Jan 23, 2004)

If your fork bushings are tight, the fork can feel great after a service but gets sticky really quickly as the tight bushings plow the lube oil off the stanchions.

Bushing clearance for ideal sliding is about as much clearance as you can run without creating noticable play or knocking. The clearance is needed for lubrication film.

RS and Fox have tightened up their fork bushings a lot in the last few years. Fox went from ridiculously sloppy to almost Ohlins tight.


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## digev (Mar 7, 2019)

Dougal said:


> If your fork bushings are tight, the fork can feel great after a service but gets sticky really quickly as the tight bushings plow the lube oil off the stanchions.
> 
> Bushing clearance for ideal sliding is about as much clearance as you can run without creating noticable play or knocking. The clearance is needed for lubrication film.
> 
> RS and Fox have tightened up their fork bushings a lot in the last few years. Fox went from ridiculously sloppy to almost Ohlins tight.


Thanks Dougal, it's always nice to hear about your experience and feedback 

The most ridiculous was an almost brand new Pike ultimate, I've had to use the tool about 10/15 times in each leg before it went smooth ... shockingly tight!

BTW: thanks a lot for the Supergliss 100k, it's ridiculously good, I'm hooked 

Using a small paint brush to lube the bushings, it was not even dripping, it's sticking to the surface but it's super slippery at the same time ... perfect for the job. So glad to have 10cc of this amazing oil in each leg now!


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## Radical337 (Jun 7, 2019)

Great stuff. I had the exact same problem. Brand new 2019 RS Rev fork. TERRIBLE stiction off the top and just notchy/harsh throughout the entire stroke. Sent it back to SRAM for warranty. Of course they didn't do anything other than service the lowers and call it 'good' for the very reasons you listed above. So I sent it off to Ryan @ Fluid Focus. 

Tight bushings. He honed them, rebuilt the lowers and sent it back and said enjoy...and he was right. It is smooth as glass now.


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## CCS86 (Jan 6, 2020)

Great post!

I recently did the 200 hr service on my Recon RL and while I did lightly wet sand the bushings, I am now kicking myself for not checking fit with the guts removed.

On a similar note, when I tore my rear suspension apart for inspection on my Marin Rift Zone; four out of the six bearings felt crunchy. But once I pressed them out of the frame and rocker they felt fine.

Calipers came out to confirm my suspicion. All the bearing bores were way too small. I'd say about 0.001" interference fit is good for a bearing of this size, and they were all -0.006"!

I ended up designing and making a custom tool to resize these bores,while retaining cylindricity. New Enduro Max bearings run beautifully installed and the bike is much better at ironing out the small stuff. 

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## tbmaddux (May 22, 2012)

CCS86 said:


> I ended up designing and making a custom tool


Pictures or it didn't happen.


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## CCS86 (Jan 6, 2020)

tbmaddux said:


> Pictures or it didn't happen.




I'm actually looking into patent protection for it right now. I'm a mechanical engineer who works in CNC Manufacturing and don't think this tool exists.

The design is scalable for essentially any size and depth. It works on bores with a flange, which prevents the use of normal cylinder honing tools. It requires no special fixturing. Works on anodized bores. It can be made quickly and relatively cheaply and can be used by a novice with a hand drill.

With so much manufacturing out of China, I'm guessing undersized bores aren't that rare.

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## CCS86 (Jan 6, 2020)

Here is the frame bore after reworking. Before it was full of mill chatter.









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## digev (Mar 7, 2019)

CCS86 said:


> Great post!
> 
> I recently did the 200 hr service on my Recon RL and while I did lightly wet sand the bushings, I am now kicking myself for not checking fit with the guts removed.
> 
> ...


Thank you! Woow, you're quit the mechanic.... that was risky, what a story! Well it proves that tolerance variations are pretty common when building stuff at the industrial level and while it kinda works you could also find yourself at the very limit of what's acceptable for QC. I guess that's what happened with your bearing/frame story, and it's definitely the case with fork bushings! Your frame was alloy right? Do you mind sharing more info, pics of the tool? I love those stuff AND happy ending stories. LOL 

FYI: I don't think wet sanding bushings are a good idea, (I could be wrong). You seem to be the kind of guy who can do better and make his own resizing tool!


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## digev (Mar 7, 2019)

Radical337 said:


> Great stuff. I had the exact same problem. Brand new 2019 RS Rev fork. TERRIBLE stiction off the top and just notchy/harsh throughout the entire stroke. Sent it back to SRAM for warranty. Of course they didn't do anything other than service the lowers and call it 'good' for the very reasons you listed above. So I sent it off to Ryan @ Fluid Focus.
> 
> Tight bushings. He honed them, rebuilt the lowers and sent it back and said enjoy...and he was right. It is smooth as glass now.


Glad he did a proper job! It's too often overlooked. Hence why you should go to a REAL suspension tuner ... easiest and safest way to enjoy the benefit of a slick suspension!


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## digev (Mar 7, 2019)

CCS86 said:


> I'm actually looking into patent protection for it right now. I'm a mechanical engineer who works in CNC Manufacturing and don't think this tool exists.
> 
> The design is scalable for essentially any size and depth. It works on bores with a flange, which prevents the use of normal cylinder honing tools. It requires no special fixturing. Works on anodized bores. It can be made quickly and relatively cheaply and can be used by a novice with a hand drill.
> 
> With so much manufacturing out of China, I'm guessing undersized bores aren't that rare.


That's super cool! Good on you


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## digev (Mar 7, 2019)

Could the stock bushings be replaced by those?

https://www.igus.com/product/3










Do the mechanical properties match what's needed for a MTB fork?

Example:
------
Maximum running speed, linear, continous
1,575 fpm (8.0 m/s)
Maximum running speed, linear, short-term
1,969 fpm (10.0 m/s)
Coefficient of sliding friction, dynamic, against steel
0.06 - 0.18 μ
------

They make them in:

35mm ID - 39mm OD
36mm ID - 40mm OD

ID is fine but what about the OD?

And you can request a free sample


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## Radical337 (Jun 7, 2019)

digev said:


> Glad he did a proper job! It's too often overlooked. Hence why you should go to a REAL suspension tuner ... easiest and safest way to enjoy the benefit of a slick suspension!


Def. Truth be told, after SRAM but before sending off to Fluid Focus, we even installed the Charger 2.1 RCT3 damper upgrade which effectively turned this fork into a Pike Ultimate thinking it would solve the problem. The sealed cartridge being smaller did mitigate some of the problem but it was just so obvious something else was going on. That's when I sent it off to FF. Point is...yes, if you are experiencing similar issues, no need to waste a lot of time and $$ on needless work....it's almost certainly under sized bushings. Send it off to someone who knows what they are doing


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## CCS86 (Jan 6, 2020)

digev said:


> Thank you! Woow, you're quit the mechanic.... that was risky, what a story! Well it proves that tolerance variations are pretty common when building stuff at the industrial level and while it kinda works you could also find yourself at the very limit of what's acceptable for QC. I guess that's what happened with your bearing/frame story, and it's definitely the case with fork bushings! Your frame was alloy right? Do you mind sharing more info, pics of the tool? I love those stuff AND happy ending stories. LOL
> 
> FYI: I don't think wet sanding bushings are a good idea, (I could be wrong). You seem to be the kind of guy who can do better and make his own resizing tool!


Yes, frame was alloy, and a committed move! I worked on the rocker arm bores first to prove the concept. After I worked on the first bore, I kept measuring it over and over, not believing I was already up to perfect size so easily. It actually improved the roundness of the bore, as evidenced by uneven removal of the anodization.

I'm not 100% on whether wet sanding the bushings is a good idea or not. I used 800 grit bathed in oil, and removed all grit afterwards. I have worked with Igus bushings before, and don't think surface finish is super critical. Even if it is, you can go all the way up to optically clear on plastic by increasing the grit of the compound. A proper tool to cut to size is most definitely a better option.


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## digev (Mar 7, 2019)

Radical337 said:


> Def. Truth be told, after SRAM but before sending off to Fluid Focus, we even installed the Charger 2.1 RCT3 damper upgrade which effectively turned this fork into a Pike Ultimate thinking it would solve the problem. The sealed cartridge being smaller did mitigate some of the problem but it was just so obvious something else was going on. That's when I sent it off to FF. Point is...yes, if you are experiencing similar issues, no need to waste a lot of time and $$ on needless work....it's almost certainly under sized bushings. Send it off to someone who knows what they are doing


Amen to that!


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## CCS86 (Jan 6, 2020)

digev said:


> Could the stock bushings be replaced by those?
> 
> https://www.igus.com/product/3
> 
> And you can request a free sample


I have worked with Igus before and they make a great product. They sell direct to consumer and their technical sales people are super helpful. You could reach out to them with the details of the application and they will help you select the correct bushing material.

I'm pretty sure they will even do custom sizes, obviously at a higher price point.


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## digev (Mar 7, 2019)

CCS86 said:


> Yes, frame was alloy, and a committed move! I worked on the rocker arm bores first to prove the concept. After I worked on the first bore, I kept measuring it over and over, not believing I was already up to perfect size so easily. It actually improved the roundness of the bore, as evidenced by uneven removal of the anodization.
> 
> I'm not 100% on whether wet sanding the bushings is a good idea or not. I used 800 grit bathed in oil, and removed all grit afterwards. I have worked with Igus bushings before, and don't think surface finish is super critical. Even if it is, you can go all the way up to optically clear on plastic by increasing the grit of the compound. A proper tool to cut to size is most definitely a better option.


You did a great job! Thanks for sharing that story.

You're probably right about the surface finish, as long you have enough clearance and lubrification it should be OK! Well it does feel ok NOW HeyHey.


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## digev (Mar 7, 2019)

CCS86 said:


> I have worked with Igus before and they make a great product. They sell direct to consumer and their technical sales people are super helpful. You could reach out to them with the details of the application and they will help you select the correct bushing material.
> 
> I'm pretty sure they will even do custom sizes, obviously at a higher price point.


You know what? I'll send them an email out of curiosity and see what they have to say. We never know ...


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## mike156 (Jul 10, 2017)

What's stopping them uppers from dropping completely in? Looks like you are dropping them through the first set of bushings and then they are stopping on the second set of bushings? If that's the case, seems like there may be more gains to be had with figuring out a way to align the bushing bores better?

Aren't the stock bushings lined with PTFE, basically making them a metal backed IGUS bushing?

How consistent in sizing are the stanchions?

0.0015" to 0.009" is wider then what I thought it would have been. Wonder how open you can go before it starts making noise.

Anywhere in the USA selling supergliss?


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## jimarin (Mar 19, 2005)

Good find on that bushing sizer tool. Thats well worth $150.


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## digev (Mar 7, 2019)

jimarin said:


> Good find on that bushing sizer tool. Thats well worth $150.


Thanks! Even regular bike shops can buy it without breaking the bank. If customers don't ask yet that's because they don't know about the whole bushings thing but if you explain it to them and add that service as part of the regular maintenance you do on forks, I'm sure they'll be pretty happy!

But even just for one guy, it's worth it ...

How much is your bike? How much is your fork? How much do you spend on BS upgrades because ... we all do  then you realize it's really not that expensive knowing you will keep it forever and the «regular» forks aren't going anywhere soon ... RS will keep their 35mm stanchions for a very good while and if they ever change ... you just need to spend a few dollars to buy a new (head) and boom ... you're back in business! Just an example of how futur proof it is ...

It's proudly made in the USA and you will support a very clever guy trying to improve our MTBiker's life with ingenious solutions/tools without murdering anyone with stupid prices! Super easy to deal with and very fast turnaround.

I'm from Europe but I know you guys like that kind of stuff 



> Oliver Majewski is a bicycle mechanic, engineer and machinist specializing in the stuff that you can't get anywhere else.


I like that, I like that a lot. LOL 

Have a look at his website: http://blueliquidlabs.com

Plenty of custom stuff/tools ... dig a little because not everything is visible from the homepage! I'm actually trying to increase my SB130 travel to something that's not even possible on the market (just because) ... but he can make custom (everything) to make it happen. Really good stuff and really interesting...


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## PHeller (Dec 28, 2012)

Glad Oliver is getting some exposure. He's a good guy. 

Just so we're clear: there is no downside to slightly more loose bushings until they start to make noise/rattle or compromise stiffness? 

I thought more loose bushings created quicker wear and that was part of the problem of the older Fox forks.


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## GH28 (Jun 16, 2014)

A .009"D clearance should basically make the fork un-usable...

.002-.004"D is a good target.

Loose bushings will wear the stanchions super fast also. The heel/toe action of the two bushings against the shaft will give a lot of force to the leading edge of the bushings.


And a .006"D interference of a steel bearing into an aluminum housing sounds like there is some major measurement error going on....at that point, you'd be breaking material on one side or the other. A .0005-.001"D interference is desired for a modest press fit. 5-10X that is damaging something, and the bearings aren't that flexible...

Also, hate to break it to you, but if you just posted it on a public forum prior to patent filing, whatever patent you get filed and accepted by the USPTO can be invalidated with zero effort. If you've got a good idea, don't tell anyone.


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## 294037 (Jun 30, 2006)

PHeller said:


> Glad Oliver is getting some exposure. He's a good guy.
> 
> Just so we're clear: there is no downside to slightly more loose bushings until they start to make noise/rattle or compromise stiffness?
> 
> I thought more loose bushings created quicker wear and that was part of the problem of the older Fox forks.


Older fox forks either had tight bushings or a lot of them suffered from the bath oil migrating in to the air chamber or damper and running dry

Go back even further to some of the earliest fox forks and they had more bushing clearance and are still running mint to this day!

Oliver is a real smart guy, I've bought tools from him too and he makes good stuff


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## Ole (Feb 22, 2004)

Here's my 36 after having been to a Fox service center twice, and having been called a difficult customer. Took this video showing 4.5kg (10 pounds) of static friction before the legs move. Plus the weight of the lower legs and the scale, so around 5.5kg or 12 pounds. Sent the fork in one more time and it was finally fixed.

https://photos.app.goo.gl/yfZDkGQqYDv5t15XA


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## Dougal (Jan 23, 2004)

digev said:


> When you buy the Fox «FORK BUSHING SIZING TOOL ASSY» you get two cylinders/heads (sorry I don't know how it's called) of almost the same size.
> 
> For example you get a 36.0mm and a 36.1mm
> 
> ...


The only use I can see for a 36.0mm pilot is to force one that is way out of shape (i.e egg shaped from install) into the first stage of round so you can use the normal burnishing head.

What this process does is effectively the same as a lot of riding. What was known as "fork break-in". The forks that have had a good seasons riding (as long as they haven't damaged stanchions) end up perfectly sizing themselves.

My sizing tools are in this post:

__
http://instagr.am/p/Bvu6O4Ql9Ye/










Made these myself, sizes from 28.6mm through 40mm. Not all of them are shown there.
We have found 35mm Marzocchi is smaller than 35mm RS. You'd need a tool for each of those.


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## Dougal (Jan 23, 2004)

digev said:


> Could the stock bushings be replaced by those?
> 
> https://www.igus.com/product/3
> 
> ...


Those only work if the fork has been designed for them. Magura used this bushing style on one of their forks and used grease lubrication. But I've never seen one in person.

Every other fork has an aluminium bearing carrier with a PTFE bearing layer bonded onto it. These are a press-fit into the lower legs in a way that the IGUS bushings above may not stay. The wall thickness of the aluminium PTFE bushings is thinner and they are pretty much unique diameter/thickness for each fork.


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## digev (Mar 7, 2019)

Ole said:


> Here's my 36 after having been to a Fox service center twice, and having been called a difficult customer. Took this video showing 4.5kg (10 pounds) of static friction before the legs move. Plus the weight of the lower legs and the scale, so around 5.5kg or 12 pounds. Sent the fork in one more time and it was finally fixed.
> 
> https://photos.app.goo.gl/yfZDkGQqYDv5t15XA


Excellent ... Glad you got it sorted! A nice video was probably the best way to show people what it really feels/looks like ... how do you want you fork to be smooth when it's locked like that 

Nice one! Thanks for sharing!


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## mullen119 (Aug 30, 2009)

GH28 said:


> A .009"D clearance should basically make the fork un-usable...
> 
> .002-.004"D is a good target.
> 
> ...


.009 is total clearance, which would be .0045 on all sides assuming everything is in alignment and the stanchion is centered. This the upper limit for all manufacturers. .006-.007 is the sweet spot

Bushings have a spring quality, so the bushing mandrel needs to be larger than the desired ending measurement because the bushings will shrink back a little bit. The biggest benefit is not resizing anyway, it's making the bushing round. Most are ovalized to some extent and fixing that is a huge upgrade


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## digev (Mar 7, 2019)

mullen119 said:


> .009 is total clearance, which would be .0045 on all sides assuming everything is in alignment and the stanchion is centered. This the upper limit for all manufacturers. .006-.007 is the sweet spot
> 
> Bushings have a spring quality, so the bushing mandrel needs to be larger than the desired ending measurement because the bushings will shrink back a little bit. The biggest benefit is not resizing anyway, it's making the bushing round. Most are ovalized to some extent and fixing that is a huge upgrade


Very interesting, thank you!

0.006" = 0.15mm

I measured my mandrel at 35.1mm with a «cheap» caliper. That's still too narrow?

If the bushings shrink back a little after using the tool, what size should the mandrel be to get to that final +0.006" please? Or do you have an opinion about the % to add to compensate for that «shrinking»?


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## nikon255 (Dec 27, 2015)

digev said:


> Very interesting, thank you!
> 
> 0.006" = 0.15mm
> 
> ...


it will be ok, even with thick supergliss.


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## digev (Mar 7, 2019)

If you buy a Formula you shouldn't get that issue 










Source: https://m.pinkbike.com/news/formula-35-review-2017.html


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## mullen119 (Aug 30, 2009)

digev said:


> Very interesting, thank you!
> 
> 0.006" = 0.15mm
> 
> ...


My fault, I get confused when switching back and forth between metric and imperial. Let me try this again

.09mm is the upper limit, .06-.07mm is the sweet spot. .04mm would be tight.

.1mm over stanchion diameter is the normal tolerance for a bushing mandrel. After passing through, the bushings will slightly shrink back down to the desired .06-.07 after a few passes. if you pass through enough times, you might hit the .08-.09 limit. In a lot of cases, you are not actually enlarging them at as, just taking out a ovalization.


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## digev (Mar 7, 2019)

Oh great, so 0.1mm is perfect! Didn't know about the oval to round thing ... either way it helps. Thank you very much for the clarification about sizing/shrinking/shaping


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## Dougal (Jan 23, 2004)

digev said:


> If you buy a Formula you shouldn't get that issue
> 
> 
> 
> ...


Everyone else just makes stanchions all to the same tolerance...........

If they didn't/couldn't, loose bushings are the least of your concerns. Crown Press Fit has entered the game!

So yeah, pinkbike claim is bollocks.


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## CCS86 (Jan 6, 2020)

Dougal said:


> Everyone else just makes stanchions all to the same tolerance...........
> 
> If they didn't/couldn't, loose bushings are the least of your concerns. Crown Press Fit has entered the game!
> 
> So yeah, pinkbike claim is bollocks.


Not sure I understand your reasoning here.

I work in engineering and manufacturing. Categorizing finished parts by size for intelligent assembly matching is absolutely a thing.

With a small logistical effort you can achieve the same end result for fit, as cutting your dimensional tolerances in half, without driving cost and scrap rate through the roof.

Sent from my Pixel 4 using Tapatalk


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## mullen119 (Aug 30, 2009)

CCS86 said:


> Not sure I understand your reasoning here.
> 
> I work in engineering and manufacturing. Categorizing finished parts by size for intelligent assembly matching is absolutely a thing.
> 
> ...


There should be no variations in stanchion diameter. If there is, where the stanchion is press fit into the crown would be compromised and a far bigger issue than bushing sizes.

If stanchion diameter is consistent like it should be, bushing sizes would be the only variable that they are measuring.


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## Dougal (Jan 23, 2004)

CCS86 said:


> Not sure I understand your reasoning here.
> 
> I work in engineering and manufacturing. Categorizing finished parts by size for intelligent assembly matching is absolutely a thing.
> 
> ...


Excellent.  You'll know the tolerances for press-fit are almost a magnitude tighter than the tolerances for sliding bushing fit.

Which is why the above pinkbike claim is rubbish. By the time you have a tube within tolerance for press-fitting into a crown, it is well inside the tolerance windows for bushing fit.

You do not grade stanchions for bushing fit. Stanchions are made to a tight diameter tolerance. All variation is in your bushings and they can all be sized to the same fit.


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## digev (Mar 7, 2019)

Source: https://singletrackworld.com/2016/03/review-formula-35-forks/

While I totally understand the need for tighter tolerances regarding stanchions (because they are press-fit), why would they be equipped and spend time measuring the whole stanchions/bushings fit during manufacturing? Surely they would know if it was bollocks? I have a hard time to believe they would «just» say that and not do it ... they invite media for factory tours etc... that would be difficult to say something like that and not show it to them. No?


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## CCS86 (Jan 6, 2020)

Dougal said:


> Excellent. You'll know the tolerances for press-fit are almost a magnitude tighter than the tolerances for sliding bushing fit.


Honestly, that is arguable, since the fit for a bushing is more subjective; and depending on the application, the allowance range between bind/friction and too loose can be very small.



Dougal said:


> You do not grade stanchions for bushing fit. Stanchions are made to a tight diameter tolerance. All variation is in your bushings and they can all be sized to the same fit.


You are right. I do not grade stanchions... because I don't make stanchions. Do you?

How can you say that stanchions are "made to a tight tolerance", then say *"all"* variation is in the bushings? You are contradicting yourself.

Even if stanchions are made to a tight tolerance, there is variance by definition; both in average diameter and in roundness/cylindricity. Then you have to stack on the tolerance for whatever surface treatment / coating they get.

Even if the variance in bushings is greater, and I would believe that, there is variance in both. Period.



Dougal said:


> Which is why the above pinkbike claim is rubbish. By the time you have a tube within tolerance for press-fitting into a crown, it is well inside the tolerance windows for bushing fit.


You speak so absolutely, I would think you have been to the factory and watched them not doing this matched fit.

Interference fits don't have to be as precise as you are making it out. Especially if they are shrink fitting (using thermal expansion). You want an extremely strong connection between the stanchion and crown. So, your only real limit to the amount of interference is ease of assembly and the tensile strength of the crown.

For example: the bearing bores on my Marin were all 0.006" interference fit, which for a dainty little roller bearing, is wayyyyy to tight. But they still pressed in at the factory. It "worked". The only symptom was that the outer race was over-compressed and partially binding the bearing. If it was a dumb part like a stanchion, you wouldn't even know.


----------



## Dougal (Jan 23, 2004)

CCS86 said:


> Honestly, that is arguable, since the fit for a bushing is more subjective; and depending on the application, the allowance range between bind/friction and too loose can be very small.


It is not arguable at all. Press fit is almost a whole magnitude smaller tolerance window than fork bushings.



CCS86 said:


> You are right. I do not grade stanchions... because I don't make stanchions. Do you?


No I don't make stanchions. I do however repair stanchion to crown press-fits and have measured many across all the common brands.

So I have done the equivalent of quality control measurements on many. I know the tolerances required.

They are not shrink fit and your ideas on what limts the fit are incorrect. Many forks have a press-fit so loose the stanchions can walk out of the crown if the caps are loose: Here is one:

__
http://instagr.am/p/BqIjZwWljU6/


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## Dougal (Jan 23, 2004)

digev said:


> Source: https://singletrackworld.com/2016/03/review-formula-35-forks/
> 
> While I totally understand the need for tighter tolerances regarding stanchions (because they are press-fit), why would they be equipped and spend time measuring the whole stanchions/bushings fit during manufacturing? Surely they would know if it was bollocks? I have a hard time to believe they would «just» say that and not do it ... they invite media for factory tours etc... that would be difficult to say something like that and not show it to them. No?


It could simply be someone in management who doesn't understand the basics and thinks "technology" will save them. I see that a lot.

That article sounds more like they are matching crown spacing to lower leg spacing. Many companies (including Fox and Marzocchi) have produced forks with crown spacing not matching the lower castings. Makes for a pretty sticky fork.


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## CCS86 (Jan 6, 2020)

Dougal said:


> It is not arguable at all. Press fit is almost a whole magnitude smaller tolerance window than fork bushings.


I'm trying to say that while press fits are governed by a tight window of being able to provide the function of staying in place, bushing fits are subjective in what is an acceptable amount of free-play. I don't doubt that the fork mfg acceptable range of bushing fit is far looser than a press fit. But in a different application, the loose end of a fork bushing fit, might be totally unacceptable. It sounded like you were making a general statement that all bushing fits are an order of magnitude looser than press fits, and that isn't true.

What is incorrect about my ideas on press fit limitations? When I pointed out the error in your statement about stanchions not having any variance, I explained why.


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## CCS86 (Jan 6, 2020)

An FN 5 fit on a 35mm diameter shaft would have between 0.0014" - 0.004" interference. That is a tight tolerance, but not crazy.


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## Dougal (Jan 23, 2004)

CCS86 said:


> I'm trying to say that while press fits are governed by a tight window of being able to provide the function of staying in place, bushing fits are subjective in what is an acceptable amount of free-play. I don't doubt that the fork mfg acceptable range of bushing fit is far looser than a press fit. But in a different application, the loose end of a fork bushing fit, might be totally unacceptable. It sounded like you were making a general statement that all bushing fits are an order of magnitude looser than press fits, and that isn't true.
> 
> What is incorrect about my ideas on press fit limitations? When I pointed out the error in your statement about stanchions not having any variance, I explained why.


I think you need to go back and read what I actually wrote.

The tolerances you have posted are not workable for a fork stanchion.


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## 294037 (Jun 30, 2006)

I would not put too much stock in tech claims from marketing material made by Italian companies, they are notorious for printing blurb that may as well be directly spat out by google translate. Then once you take Pinkbike’s “expert” interpretation of it, who knows what the original intent could be, they were probably describing a carbonara recipe for all we know

And can we please stick to metric measurements like normal civilized people? We aren’t in the 1950’s!


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## davideb87 (Dec 13, 2017)

I'm italian and basically half of my Friends ride on a formula selva.
I don't comment that technical informations, but i assure you that formula should NOT be taken as a good example for bushings tolerance.
Most of them are trash within a year, there are so many cases of bad bushings and play that it can't be described as accidental, there is a problem in their method.

As a italian i really don't like to comment an italian company in a bad way ( also have their brakes which are amazing), but using formula forks as a example of excellence for bushings is so far from real that i can't pass on that.
Down here you buy a selva and you are aware that there are very high chances that you'll need to replace bushings after a season, everyone knows it.


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## romphaia (Sep 7, 2014)

Formulas have relatively loose bushings by design, to help lubrication (bushings aren't slotted) and be super smooth out of the box, obviously this has consequences on longevity. At least their bushings ARE replaceable.

Tolerances for press fit headset cups are 0.1-0.15mm. I have no experience with replacing stanchions or steerers but it would be hard, and scary, to think they would be looser than that!


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## digev (Mar 7, 2019)

Fair enough! It was still good to read what everyone had to say about all this ...

You cracked me up with that «carbonara recipe» 

Just read something cool on the SKF website about the difference between PTFE and POM, especially designs and variants.

The POM composite (bushings) seem to have a lot of interesting features compared to the simpler PTFE design.

Especially for lubrification.












> Excellent in dirty environments due to lubrication pockets ... Optimized for minimal maintenance in difficult environments
> 
> Pockets in the sliding surface make these bushings suitable for applications that require minimal maintenance under difficult operating conditions, for example in contaminated environments where lubricant cannot be supplied continuously or frequently. Therefore, the grease reservoirs should be filled prior to installation. Despite of their compact design, POM composite bushings can accommodate heavy radial loads and are less sensitive to misalignment.


https://www.skf.com/us/products/pla...rust-washers-strips/bushings/designs-variants

https://www.skf.com/binaries/327-12...F-bushings-thrust-washers-and-strips-1-EN.pdf



















What do you think?!


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## nightnerd (Mar 5, 2007)

Digev, I watched again your video where your uppers just drop in the lowers. maybe i'm wrong but it almost look like the uppers stops when the stancions reach the first set of bushing. I'm asking because I have a have a 2015 acs3-ed fox 36 that i always found harsh. I'm trying to find the best way to assess if the problem comes from the bushing being too tight. Maybe others can help as well explaining the best way to validate or invalidate if a fork has that issue. Thanks!


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## digev (Mar 7, 2019)

nightnerd said:


> Digev, I watched again your video where your uppers just drop in the lowers. maybe i'm wrong but it almost look like the uppers stops when the stancions reach the first set of bushing. I'm asking because I have a have a 2015 acs3-ed fox 36 that i always found harsh. I'm trying to find the best way to assess if the problem comes from the bushing being too tight. Maybe others can help as well explaining the best way to validate or invalidate if a fork has that issue. Thanks!


When I dropped the uppers they were already in the first set of bushings THEN they stopped because they've hit the second set of bushing ... I guess it's almost impossible to accurately hit the second set so they can carry on dropping. But when you «manually» guide the uppers into the second set, push them down then pull them up a few times it's still super smooth, unlike before.

If you want to check if your fork suffers from tight bushings, you should:

Empty the fork completely and keep only the chassis (uppers/lowers). So you remove everything else from the equation. (Everything, even the fork seals or the front axle)

Then you cycle the uppers into the lowers by hand ... I'd suggest you do a dry run first (literally) so it's even more obvious if they are tight and/or oval!

you can also put only one stanchion into it's leg to see if one side is worse than the other but that's about it!

it's not rocket science, they either slide freely/smoothly or they don't, and if they don't ... well, it probably translates into some form of harshness while riding, (essentially at the beginning of the stroke) but the good news is ..., now you know what to do 

Don't forget to relube the 4 bushings with a sticky and super slippery oil such as the Motorex Supergliss range with a paint brush and use the same oil to bath the foam rings and into your lowers.

Pick the best for your ambient temperature.










Credits go to Dougal @ Shockcraft

Source: https://www.shockcraft.co.nz/technical-support/suspension-oils/fork-bath-oils


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## Dougal (Jan 23, 2004)

JohnnyC7 said:


> I would not put too much stock in tech claims from marketing material made by Italian companies, they are notorious for printing blurb that may as well be directly spat out by google translate. Then once you take Pinkbike's "expert" interpretation of it, who knows what the original intent could be, they were probably describing a carbonara recipe for all we know
> 
> And can we please stick to metric measurements like normal civilized people? We aren't in the 1950's!


Still getting flashbacks from a decade ago huh?


----------



## Dougal (Jan 23, 2004)

digev said:


> Fair enough! It was still good to read what everyone had to say about all this ...
> 
> You cracked me up with that «carbonara recipe»
> 
> ...


Those bushing types are primarily used for rear shock eyelets under heavy rotation loads. They used to be lead coated on the inside for lubrication but now are mostly black PTFE with some red PU. The casings are a steel outer ring for strength with a bronze inner wear layer.

Fork leg bushings are lighter and simpler. Aluminium outer with creamy coloured PTFE:


----------



## Chris2fur (Jan 13, 2004)

Dougal said:


> It could simply be someone in management who doesn't understand the basics and thinks "technology" will save them. I see that a lot.
> 
> That article sounds more like they are matching crown spacing to lower leg spacing. Many companies (including Fox and Marzocchi) have produced forks with crown spacing not matching the lower castings. Makes for a pretty sticky fork.


Yes, or upper tubes not parallel. Ran into a Manitou with that issue. Needless to say, it was not smooth.


----------



## Chris2fur (Jan 13, 2004)

CCS86 said:


> With so much manufacturing out of China, I'm guessing undersized bores aren't that rare.
> 
> Sent from my Pixel 4 using Tapatalk


I don't know if it is due to the manufacturing location or due to engineers that don't understand interference fit tolerances, but your guess is correct. I can assure you it's not that rare. Way too many frames have suspension bearing sockets that are too tight, causing brand new bearing to be notchy from the get-go and to fail prematurely. ...and certain companies like to give it a double whamy by adding a strong fixative to an already too-tight fit.


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## digev (Mar 7, 2019)

Based on your experience/knowledge, what (usually) generates the most frictions in a fork?

Bushings
Dust/Wiper seals
Air Spring shaft seal
Air Spring Piston seal
Damper shaft seal
Damper piston seal


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## Dougal (Jan 23, 2004)

digev said:


> Based on your experience/knowledge, what (usually) generates the most frictions in a fork?
> 
> Bushings
> Dust/Wiper seals
> ...


Whatever has been implemented the worst really.

Any one of those can lockout a fork over small bumps if done wrong. X-Fusion made a dual quad-ring air piston which had so much stiction it could actually break the piston in two!

The real struggle is to get the sum total of all of those down to sub 2kg force while still having appropriate sealing.


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## digev (Mar 7, 2019)

Dougal said:


> Whatever has been implemented the worst really.
> 
> Any one of those can lockout a fork over small bumps if done wrong. X-Fusion made a dual quad-ring air piston which had so much stiction it could actually break the piston in two!
> 
> The real struggle is to get the sum total of all of those down to sub 2kg force while still having appropriate sealing.


Make sense! How do you measure the force? Do you just push the fork on a bathroom scale until the uppers start moving?


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## Dougal (Jan 23, 2004)

digev said:


> Make sense! How do you measure the force? Do you just push the fork on a bathroom scale until the uppers start moving?


That'll work fine.


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## Dougal (Jan 23, 2004)

romphaia said:


> Tolerances for press fit headset cups are 0.1-0.15mm. I have no experience with replacing stanchions or steerers but it would be hard, and scary, to think they would be looser than that!


Headset cups and stanchions are very different in forces and insertion depth. You could tap the steerer tube out of several popular forks today with a big rubber hammer!

Needless to say. Those are the ones with a reputation for creaking.


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## Gman086 (Jul 4, 2004)

nightnerd said:


> Digev, I watched again your video where your uppers just drop in the lowers. maybe i'm wrong but it almost look like the uppers stops when the stancions reach the first set of bushing. I'm asking because I have a have a 2015 acs3-ed fox 36 that i always found harsh. I'm trying to find the best way to assess if the problem comes from the bushing being too tight. Maybe others can help as well explaining the best way to validate or invalidate if a fork has that issue. Thanks!


The uppers stop there because of what Chris2fur stated... the uppers are NOT perfectly parallel with the lowers (which I believe are toed in). When you put on the hub and tighten the axle you would see the uppers drop into the bottom of the lowers. Not sure if fork makers do this on purpose or not but I noticed this on my '20 Fox 36 out of the box which concerned me at first until I installed the wheel.

Also, FWIW, my new 2020 fork had slightly tight bushings but after a handful of rides it's broken in with zero stiction issues. Did I get lucky? Doubtful as I'm sure I'm in the majority but for those who got dealt a bad hand, yeah, honing is the option.

Have FUN!

G MAN


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## digev (Mar 7, 2019)

Dougal said:


> That'll work fine.


Thanks! I'll try that before/after resizing bushings to measure the force/stiction difference!


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## digev (Mar 7, 2019)

Mojo Rising commenting about the forthcoming EXT ERA Fork ...



> Part two of our occasional social media series '36 (or should it be 38?) reasons to wait for a new ERA in fork design from EXT before buying your next fork
> 
> Reason number 4: EXT have been benchmarking all the enduro fork options on the dyno to find out how much stiction there is in each single part of the forks&#8230; Dampers, air shafts, seal blocks, main seals and bushes have all been tested individually and as assemblies for static and sliding friction with and without side load. You would be amazed how much support comes from stiction in a long travel, single crown fork. so much that damping is largely irrelevant at many shaft speeds&#8230;
> Reason number 5: EXT have tested a lot of different types of bushings and bushing materials in these lowers and have made massive strides forward in reducing static and sliding friction. This is music to our ears as we've learnt a thing or two about this and modified/changed/swapped/hacked countless sets of bushings over the years and nobody listened... Until now
> ...


Sounds familiar?

I really hope they publish something ... at some point. LOL

source:

__
http://instagr.am/p/B9FCWdfnSbW/


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## Novaterra (Jan 1, 2014)

Dougal said:


> That'll work fine.


cool, then my fork is ultra smooth, it looks as if i put a cup of coffee on my bars you can see the fork moving


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## GH28 (Jun 16, 2014)

Gman086 said:


> The uppers stop there because of what Chris2fur stated... the uppers are NOT perfectly parallel with the lowers (which I believe are toed in). When you put on the hub and tighten the axle you would see the uppers drop into the bottom of the lowers. Not sure if fork makers do this on purpose or not but I noticed this on my '20 Fox 36 out of the box which concerned me at first until I installed the wheel.
> 
> Also, FWIW, my new 2020 fork had slightly tight bushings but after a handful of rides it's broken in with zero stiction issues. Did I get lucky? Doubtful as I'm sure I'm in the majority but for those who got dealt a bad hand, yeah, honing is the option.
> 
> ...


All (competent) fork manufacturers should be installing the bushings and aligning them to the nominal use case, which is with a hub installed, whose length is median in the tolerance range for overall hub lengths. Likely they're using a precision tooled simulator of the stanchions as a centering/driving tool with the lowers clamped to a hub simulator. Only way to make that work with an otherwise bendy lower casting.


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## nicolasswid (Apr 15, 2014)

I have lots of friction Problems on my Rockshox SID, I made a video:





The problem is even after passing 6 times a reamer/honing cylinder at 32.12mm it is still very hard. I think my fork needs more play due to dimensional problems. I have a 32.22mm cylinder which does not enter absolutely, even with a chamfer, if I force too much, the bushings are getting damaged.

So I wonder if I can sand paper them, and then pass the 32.22mm bushing, I know it's not ideal , but it's working so bad right now.


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## mullen119 (Aug 30, 2009)

nicolasswid said:


> I have lots of friction Problems on my Rockshox SID, I made a video:
> 
> 
> 
> ...


There is an issue larger than just undersized bushings with your fork. There is no reason to go larger with burnishing the bushings. If 32.12 (which is already slightly larger than ideal) doesn't work, than you likely have some sort of larger issue.

Your video looks as if it moves relatively smoothly when there is no side load added and the forces are straight. Once you start pushing off from one side then it gets tight and binds. This would leave me to believe that it's most likely a machining error in the casting itself, or bushing is not sitting correctly in the casting. Either way, running a tool through is not going to help.


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## CCS86 (Jan 6, 2020)

If you are feeling desperate/brave, you could wet sand the stanchions.

There is a graph plotting surface roughness vs friction for plain bearings like this. The low point of friction is shockingly rough (like 250 grit). The friction rises as you go more rough and more smooth, but it rises much faster of the smooth side and gets totally out of hand at a polish.

Friction obviously isn't the only factor to manage. You have wear on the bushings and seals, ability to seal, etc. But a very light roughening could help with stiction.

Have you tried scrutinizing the the resting width between axle mating faces, compared to your hub width? (ie see if your hub is spreading the forks when you push it into place, or if there is excessive gap before clamping the axle). Doing this test with the fork aired down and compressed would be even more telling. I wish these bikes followed like motorcycles with a fully floating axle side and clamp bolts on that fork foot.


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## CCS86 (Jan 6, 2020)

I wonder how something like this would work for resizing the bushings:

https://www.mcmaster.com/2987a21


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## 294037 (Jun 30, 2006)

CCS86 said:


> I wonder how something like this would work for resizing the bushings:
> 
> https://www.mcmaster.com/2987a21


I've got a couple of these for seat tubes and they won't work. Would be more likely to chatter or straight up tear the bushing material out.


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## RS VR6 (Mar 29, 2007)

Interesting that this came up. 

I've recently noticed the black coating on my Yari on the air spring side of the stanchion start to show wear. I never noticed it until I shined a flashlight on the stanchion looking for damage. You can't really see it unless you shine a bright light on it. No noticeable wear on the damper side. I did buy the fork used...so it could have already been there. Wondering if the bushing on the air side is tighter than the damper side.


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## digev (Mar 7, 2019)

RS VR6 said:


> No noticeable wear on the damper side. I did buy the fork used...so it could have already been there. Wondering if the bushing on the air side is tighter than the damper side.


Could be, there's only one way to find out for sure! But it could also be dirt trapped by the seal! Either way, you should drop the lowers and have a look before it's too late.


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## digev (Mar 7, 2019)

nicolasswid said:


> I have lots of friction Problems on my Rockshox SID


Drop the lowers and try one stanchion at the time. If they slide «smoothly» then you don't really have tight bushings (especially if you did it already) but if the problem appears when both stanchions are in the lowers then maybe something is likely «bent», like the lowers are not aligned properly, too far appart at the end or something like that ...


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## nicolasswid (Apr 15, 2014)

Thank you very much for all your replies!

Some replies:
*I have measured the stanchion diameter to 32.03-32.05mm, by micrometer a little bigger than ideal maybe.
*The stanchion assembly is not straight! It is going wider at the bottom (0.3mm wider between stanchions).
*32.12mm is the reamer but not the final diameter of bushing. It is still very hard*to insert the reamer cylinder. I think diameter of the bushing is 32.09mm and the stanchions 32.04 mm so I think I have only 0.05mm of diameter play.
*The alignment of lower leg bushings looks OK. I inserted the reamer cylinder and check parallelism*with the stanchion assembly in the other leg... it looks OK!
*Before clamping the QR15, I have 0.8-1mm approx of total gap between hub and fork axle mating face. I tried to increase the hub width with thickness gauge (0.3-0.8mm) to compensate for the stanchions going wider on the bottom. It did work a little bit on the static test, but have no effect when sitting on the bike (as on the video).
*I am not sure I am brave enough to wet sand the stanchions! The fast black treatment would disappear?
*When I slide one stanchion at a time it is OK, low friction on the bench

Having said that, I don't really want to pay 300 USD for new stanchions, especially from Rockshox with this kind of quality control... and even more if there is a lower leg problem on the fork. So maybe only options are sanding the bushings or the stanchions...* Can friction be worse with a little looser bushings?


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## mike156 (Jul 10, 2017)

CCS86 said:


> I wonder how something like this would work for resizing the bushings:
> 
> https://www.mcmaster.com/2987a21


Its important to note here, you aren't honing/reaming the bushings. You are burnishing.

Two very different processes with very different results. Particularly on soft materials.


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## CCS86 (Jan 6, 2020)

mike156 said:


> Its important to note here, you aren't honing the bushings. You are burnishing.
> 
> Two very different processes with very different results. Particularly on soft materials.


That isn't a honing tool, it is an adjustable reamer.

Honing implies the use of abrasive media to change size/shape/surface roughness.

I work mostly with metals, but both burnishing and reaming seem like viable approaches to resizing these bushings. Assuming you have the correct tool.

Sent from my Pixel 4 using Tapatalk


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## CCS86 (Jan 6, 2020)

Can anyone confirm what ideal geometry of the burnishing tool would look like?

I have access to nice lathes, so I will probably turn myself one for my 35mm Pike.

I assume that leading with a cylindrical section that is a nice slip fit in the existing bushing size would help everything get aligned well. Then you would taper up to the oversized section. That could either be a cylindrical section as well, or even just hit the max diameter as a tangency of a fillet.


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## mike156 (Jul 10, 2017)

True, honing vs reaming is also different from each other, but they are both cutting material away. You aren't removing material with burnishing and that's the difference I was trying to point out. You are cold working it. This not only sizes it, but adds compression surface stress to close up any low spots.

The friction/wear graphs you posted are interesting in concept. Does it apply to a hard to soft surface with lubrication interface though? Also you can get secondary affects with extremely smooth surfaces that throws that out the window. If you've ever seen a DLC demo, you know what I mean. They take two EXTREMELY smooth surfaces with very tight tolerances yet they create a nearly frictionless bearing system.


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## digev (Mar 7, 2019)

CCS86 said:


> Can anyone confirm what ideal geometry of the burnishing tool would look like?
> 
> I have access to nice lathes, so I will probably turn myself one for my 35mm Pike.
> 
> I assume that leading with a cylindrical section that is a nice slip fit in the existing bushing size would help everything get aligned well. Then you would taper up to the oversized section. That could either be a cylindrical section as well, or even just hit the max diameter as a tangency of a fillet.




























Sent from my iPhone using Tapatalk


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## CCS86 (Jan 6, 2020)

Thanks man.

Tough to tell from photos, but after talking with Oliver from Blue Liquid, it sounds like the head is just a cylinder. Very simple.

Sent from my Pixel 4 using Tapatalk


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## CCS86 (Jan 6, 2020)

Roughly how long is the tool from tip to handle?


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## mike156 (Jul 10, 2017)

Crazy, that picture makes it look tapered?


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## CCS86 (Jan 6, 2020)

mike156 said:


> Crazy, that picture makes it look tapered?


Agreed.

Perspective is a powerful thing!


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## 294037 (Jun 30, 2006)

A shallow taper makes a huge difference to how easy it is to push through, especially on the tighter ones


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## CCS86 (Jan 6, 2020)

JohnnyC7 said:


> A shallow taper makes a huge difference to how easy it is to push through, especially on the tighter ones


What angle are you talking?

Still ending with a cylinder at the oversize?

I was thinking something like this:










I wonder if a circumferential groove would help cylindrical form by providing a very light cut. Since the burnisher is relying on plastic deformation to resize and reshape, there will be some amount of elastic springback, likely contributing to form error.


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## RS VR6 (Mar 29, 2007)

digev said:


> Could be, there's only one way to find out for sure! But it could also be dirt trapped by the seal! Either way, you should drop the lowers and have a look before it's too late.


I pulled the lowers off today and looked at the bushings and felt them and didn't notice anything abnormal. I also slid the lower on one leg and moved it up and down...and the air spring side did not feel like it was any tighter than the damper side. I was kinda surprised at how much "normal" friction there actually is. It is something I've never really put too much thought into. When I do a lower leg service...I would just slide the legs back on without a thought.


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## DMdh (Oct 9, 2019)

I made one myself after reading this post, and did it with almost no taper, just enough to round out the edges and ease insertion.

Already used it in my fork and did 3 passes up a down in each leg (dont know if you could do more) and already noticed great difference!


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## digev (Mar 7, 2019)

CCS86 said:


> Roughly how long is the tool from tip to handle?


380mm Sir


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## digev (Mar 7, 2019)

DMdh said:


> I made one myself after reading this post, and did it with almost no taper, just enough to round out the edges and ease insertion.
> 
> Already used it in my fork and did 3 passes up a down in each leg (dont know if you could do more) and already noticed great difference!


That's cool 

Did you lube the bushings as well?


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## digev (Mar 7, 2019)

RS VR6 said:


> I was kinda surprised at how much "normal" friction there actually is. It is something I've never really put too much thought into. When I do a lower leg service...I would just slide the legs back on without a thought.


Yeah that info goes under the radar even if it's definitely a key element contributing to a (more) supple fork!

Back to your stanchion with some rubbing on it, now that you've noticed, just watch from time to time to see if it worsens or not. It might just come from the previous use/owner but it's been fixed since.


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## DMdh (Oct 9, 2019)

digev said:


> That's cool
> 
> Did you lube the bushings as well?


Yes, a followed the instructions posted here 

very pleased with the results, already did 2 more burnishing heads just in case a friend needs it hehe


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## digev (Mar 7, 2019)

DMdh said:


> Yes, a followed the instructions posted here
> 
> very pleased with the results, already did 2 more burnishing heads just in case a friend needs it hehe


Yesss! Nice one. Sharing knowledge, tools and stoke


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## CCS86 (Jan 6, 2020)

digev said:


> 380mm Sir


Thanks again!

Are you guys lubing the tool during the burnishing process, or using the extra friction to help reshape?


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## digev (Mar 7, 2019)

CCS86 said:


> Thanks again!
> 
> Are you guys lubing the tool during the burnishing process, or using the extra friction to help reshape?


No probs 

I'm lubing the tool + bushings while doing it! Then I clean both after each pass.


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## CCS86 (Jan 6, 2020)

I went ahead and made myself a tool yesterday, with a 35.07 and 35.10 heads for now.


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## digev (Mar 7, 2019)

CCS86 said:


> I went ahead and made myself a tool yesterday, with a 35.07 and 35.10 heads for now.


Sweeeet! Did you try them out already?

Maybe the T handle should be wider so you get more leverage while twisting?

It might sound like a stupid tip but if anybody's got a tool and wants to do it for the first time, make sure you twist/rotate it going CLOCKWISE ... going down OR up because if you twist it counterclockwise the end will unscrew itself and good luck getting it back once it falls at the bottom of the lowers!

It nearly happened to me the first time so I know it's a possibility. LOL


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## CCS86 (Jan 6, 2020)

digev said:


> Sweeeet! Did you try them out already?
> 
> Maybe the T handle should be wider so you get more leverage while twisting?
> 
> ...


Not yet, but I am pulling the fork apart this morning to do it, then going riding.

I was kind of rushing to finish when I got to the handle, so we shall see how well it works. I can always put a bigger one on if need be. I thought about welding a nut to the top, so I could use an impact driver for rotation.

I thought about that whole unscrewing thing, so I milled lugs onto my tool shank, which engage the heads. This will prevent any unscrewing.

Stay tuned!


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## digev (Mar 7, 2019)

Great stuff! That did not take you long to make it happen  Have fun using your new toy and enjoy your ride!

Let us know how it went 

Later


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## mike156 (Jul 10, 2017)

Anybody want to do a tool loan/deposit program???

Got some PUSH seals I've been meaning to throw on my Lyrik.


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## digev (Mar 7, 2019)

mike156 said:


> Anybody want to do a tool loan/deposit program???
> 
> Got some PUSH seals I've been meaning to throw on my Lyrik.


If I was in the US I'd happily send it to you.


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## RS VR6 (Mar 29, 2007)

That would be awesome if there was one of those “send to the next” guy type of rentals. I’d love to try it on my bushings.


Sent from my iPhone using Tapatalk


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## jimarin (Mar 19, 2005)

So if you do it multiple times does it get looser the more you do it or will it always be really tight still when you remove the tool? It was tough to get it through and only slightly easier getting it out. I did get it all the way through both and then pulled it out.


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## digev (Mar 7, 2019)

jimarin said:


> So if you do it multiple times does it get looser the more you do it


Yes! On a brand new friend's Pike (maybe ridden 5/6 times) I had to do it 10/12 times on each side! It was ridiculously tight. Then we went for a ride and after a few hundred meters he stopped and laughed ...

Edit: 10/12 times = 5/6 top to bottom then back up again


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## jimarin (Mar 19, 2005)

digev said:


> Yes! On a brand new friend's Pike (maybe ridden 5/6 times) I had to do it 10/12 times on each side! It was ridiculously tight. Then we want for a ride and after a few hundred meters he stopped and laughed ...
> 
> Edit: 10/12 times = 5/6 top to bottom then back up again


So final desired result would be you can just take it in and out with out too much effort? I only put it through my boxxer once and it was a little better than when I rode it but still seems like there's some to go. One of the best riding dh forks I ever had (BOS) had way looser bushings than most forks I've work on and that's what I would like. Thanks I'll rip it apart today and work it.


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## digev (Mar 7, 2019)

jimarin said:


> So final desired result would be you can just take it in and out with out too much effort? I only put it through my boxxer once and it was a little better than when I rode it but still seems like there's some to go. One of the best riding dh forks I ever had (BOS) had way looser bushings than most forks I've work on and that's what I would like. Thanks I'll rip it apart today and work it.


Yes, at least that's what I did. Do it until you feel happy with the result would be my advice. Don't forget to lube those bushes during and after the process. Good luck


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## CCS86 (Jan 6, 2020)

Okay, after my first go with this tool I have a little bit of insight.

I made myself two heads, one is 35.07 and the other is 35.10. Oliver said that your (digev's) tool is 35.07, which your calipers round to 35.1

When I started with the 35.07 it was very tough to move the tool and I regretted not making the handle bigger. After a little thought I decided to make a modification. The surface finish of the head was very smooth and I speculated that this was actually increasing the friction. So, I used some 200 grit sandpaper to put a cross hatching on the tool head. This definitely helped make using the tool easier and I believe it makes the tool work faster by allowing it to very lightly cut / sweep the bushing material.

I also noticed that the upper bushing in each leg was the tightest and the lower bushings were significantly looser to begin with.

I actually used the tool dry rather than lubricated (Oliver says he does it this way too) which certainly made it a little bit harder to use, but I think that it helps the tool work by allowing some friction and heat at the interface. What I ended up doing was twisting the tool as I drove it to depth, then once it was fully engaged in a bushing I kept spinning the tool maybe five or more full rotations to build extra heat. Then I would leave the tool in place for a few minutes, while everything cooled down, in hopes that it would help improve cylindricity by holding form as the bushing cooled. I'm not sure how much of a difference that makes it was just an intuitive thing to try.

I also made a 3D printed alignment tool that I put on the shaft of my tool so that once I was through the upper bushing I could slide this part into place and help keep the tool aligned and prevent it from rotating off axis (see attached picture}. This, in addition to the slip fit nose of my tool head helped keep everything well aligned.

With the amount of force you were putting into the tool it's very important how you hold the lower fork leg to prevent twisting or breaking the brace. or even deforming the lower leg and bushing as you are using the tool by clamping too close to that area. I used soft jaws in my vise to clamp the leg I was working on, down near the axle where there is more material to support the loads.

I worked each leg maybe four times in and out, cleaning all surfaces in between. It does get a bit easier each time, showing that the tool is working. I checked fit and it felt pretty good so I called it there and reassembled the fork as my window to ride was starting to close. The forks motion is much improved after doing this for sure and after riding it the difference is very noticeable. The small bump compliance is definitely improved and the fork felt better overall.

I will probably tear it back apart again soon to work the bushings a little more as I think it could stand to loosen a touch more. I may even try putting a circumferential groove in the head of my tool, that would allow it to scrape any high spots out of the bushing as it presses through.


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## digev (Mar 7, 2019)

CCS86 said:


> Okay, after my first go with this tool I have a little bit of insight.
> 
> I made myself two heads, one is 35.07 and the other is 35.10. Oliver said that your (digev's) tool is 35.07, which your calipers round to 35.1
> 
> ...


Thank you for this detailed feedback! I'm not too surprised about the whole 35.07 thing because I used a cheap caliper. Still it's very good to know because we're talking about a 33% difference, it's quit something.

I just measured the handles and they are 13mm long. It does help to have more leverage while twisting.

Same experience with the upper bushings being tighter than the bottom ones. Across 4 different RS forks.

About the whole surface/heat feedback. When I tried it for the first time I did not put any oil on the tool or bushings but after working the first leg once I removed the tool ... that's when I realized the tool head was warm and thought maybe I went to fast or it needed oil to decrease friction.

The inside has a very thin PTFE coating/layer and I did not want to damage it with the heat. (unfounded?)

I then re-did it much slower with 100k Supergliss and it was (obviously) much easier to work the bushings after that. And they were still opening more and more after each pass. So I don't know if there's a known or right way to do it but I'd be glad to know 

You killed it with the alignement tool, great idea!

To hold the fork I was stepping on the front axle with my foot and after twisting a little bit to the right it stopped as I kept turning clockwise. I know it's probably not the most suitable way to do it but it did the job.

Now, about what it did ... because that's probably the most important factor. What you described is really what we all felt straight away, improved small bumps compliance and a bit more active and supple everywhere else. The end result will greatly depend on how tight they were to begin with! On the Pike's friend it was night and day.

Cool stuff that you did here, well done!


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## DMdh (Oct 9, 2019)

I worked each leg 3 times in and out, so 6 passes across the bushings in total, the first time it was pretty tight, but the next 2 it was way more loose.

How many times did you pass it guys?


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## digev (Mar 7, 2019)

Dropped the lowers of my Boxxer today to give it the «special treatment» and OMG it was the tightest bushings by far, especially on the spring side ... I'd say it took about (I lost count after a while because it was ridiculous) 6/7 tries with 20 rotations on each bushing, the damper side was better but still something like 4/5 tries and 10/15 rotations. Now the uppers fall straight into the lowers but it took 45mns and some sweating, wile applying Supergliss on the tool head and bushings each time.

Strangely enough I've never managed to get this fork plush even after 3 seasons. Riding it just a few months per year! Hmmm...

I can't wait for the bike park season to start and confirm that it was in fact related to stupidly tight bushings ruining the show!


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## jimarin (Mar 19, 2005)

Yea man my boxxer was crazy tight too.


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## nicolasswid (Apr 15, 2014)

Hello, the two mating surface of the fork are separated of 110.9mm when "free" (without axle tightened). The hub is 110mm. So there is 0.9mmof gap. Is it too much? How much is it supposed to be?

When axle is not tightened, the fork does not feel better


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## CCS86 (Jan 6, 2020)

nicolasswid said:


> Hello, the two mating surface of the fork are separated of 110.9mm when "free" (without axle tightened). The hub is 110mm. So there is 0.9mmof gap. Is it too much? How much is it supposed to be?
> 
> When axle is not tightened, the fork does not feel better


Is that with the fork fully extended?

You might try airing it down, put a bungee between the crown and bars to hold it compressed, and check again.

Sent from my Pixel 4 using Tapatalk


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## digev (Mar 7, 2019)

nicolasswid said:


> Hello, the two mating surface of the fork are separated of 110.9mm when "free" (without axle tightened). The hub is 110mm. So there is 0.9mmof gap. Is it too much? How much is it supposed to be?


+/- 2mm according to the Fox website!










Source: https://www.ridefox.com/fox17/help.php?m=bike&listall=specsheets

I guess RS has pretty much the same tolerances. What happens when you cycle the fork with the axle in place but un-tightened? Does it make a difference?


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## digev (Mar 7, 2019)

2 short videos to show the difference before and after burnishing/resizing the bushings!

Before
https://streamable.com/dpeq41

After
https://streamable.com/5i5mjj

credits: #thesuspensionlab
Source: https://www.instagram.com/s/aGlnaGxpZ2h0OjE3OTcxMjgwMjIxMjY5ODkx?igshid=y6fd6ad0jbik


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## CCS86 (Jan 6, 2020)

digev said:


> 2 short videos to show the difference before and after burnishing/resizing the bushings!
> 
> Before
> https://streamable.com/dpeq41
> ...


Ahh man, that poor fork can't hold its position! What have you done?



Sent from my 2PZC5 using Tapatalk


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## rain164845 (Jul 6, 2008)

Does anyone in the us have a 35mm burnishing tool for rent?

Sent from my SM-G975U using Tapatalk


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## digev (Mar 7, 2019)

Same thing for RS. The total spacing between the fork legs can vary +/- 2mm!

I've seen another drawing of a RS DC fork and the tolerance can go up to +/- 2.5mm.

It was a pretty smart move from Fox to introduce a floating axle on their latest 36/38!


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## jasonp22 (Oct 5, 2016)

Taking a step back with a very basic question - If I were to convert from air to coil spring, is bushing tightness still a concern?


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## CCS86 (Jan 6, 2020)

jasonp22 said:


> Taking a step back with a very basic question - If I were to convert from air to coil spring, is bushing tightness still a concern?


Yes. They are completely separate things.

Sent from my Pixel 4 using Tapatalk


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## digev (Mar 7, 2019)

jasonp22 said:


> Taking a step back with a very basic question - If I were to convert from air to coil spring, is bushing tightness still a concern?


Exactly, 2 different things!

if you remove the spring (air or coil) and if you remove the damper you'll end up with just the chassis (uppers/lowers) ... an empty fork if you will.

The tight bushings inside the legs will still prevent the uppers (stanchions) to slide freely up and down. See, nothing to do with the internals.

However, switching from an air spring to a coil spring is rarely a bad thing IMO  (but that's another subject all together)


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## jasonp22 (Oct 5, 2016)

Ah I see, got it. Thanks guys.


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## mike156 (Jul 10, 2017)

About to do some lockdown stretching. Guess I'll put the Push seals in that have been sitting around for months too.

Well built tool from Blue liquid labs. Maybe he can incorporate the handle into some bearing presses or something and make this a modular kit.


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## digev (Mar 7, 2019)

mike156 said:


> About to do some lockdown stretching. Guess I'll put the Push seals in that have been sitting around for months too.
> 
> Well built tool from Blue liquid labs. Maybe he can incorporate the handle into some bearing presses or something and make this a modular kit.
> 
> View attachment 1323457


Hey Hey! Sweet!!!

Very good idea about reusing some parts for another tool

Happy Burnishing


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## nicolasswid (Apr 15, 2014)

I checked the diameter of my bushings with a special tool I have for bores (T shape). After passing several times the 32.12 cylinder, the diameter of the bushings was 32.11mm. 

So with 32.04 stanchions: 0.07mm 0.0027 inches of play. I guess 0.07mm of play is OK is everything is perfectly aligned, but that's absolutely not the case here. If something is good on the RS fork, is that the bushing seems to have eternal life, it does not wear, nor breakin, which is not so good.

I sandpapered the 4 bushings until the 32.12mm tool could move more easily (possible to enter and remove with one hand), it got me to 32.18mm, so I have more or less 0.14mm of play. I removed the oil seals and used a 0.05mm feeler gauge to check where there was contact of the bushing with the stanchions. I am on the limit of the teflon coating of the bushing, there is still teflon , but it's not so thick, anyway, if the fork lasts 5 years instead of 10, it's better than going to the garbage.

First try was good during one hour, (after servicing it's always good). Then bad (frictions).* After 5 hours of ride it got better (I think surface finish was poor after sandpaper, it enhanced after a few rides. If you do this , remove the oil seal, the sand paper destroyed them (scratches). The most crazy is that even with 0.14mm play in each stanchion/bushing assembly, when the fork is assembled there is zero play, the alignment is so bad...So now it's working not so bad, but not so good...
Fork is harder when pull front (but still moving, before, it was stuck). On lateral loads, it is a little better.Now I don't know if I have to keep sanding bushing or try to deform stanchions, or wetsand stanchions... Or maybe try with supergliss if it's better.

Somebody know if on these "new" 2018 SIds the lower legs are still tapered so that I could move the bushings to increase play?

On the workshop I can see some effects when simulating a wider hub (110.9mm), but on the bike there is no difference... strange. Still there is no play in the fork with 110.0 or 110.9mm hub.


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## cesjr (Jul 13, 2011)

digev said:


> Exactly, 2 different things!
> 
> if you remove the spring (air or coil) and if you remove the damper you'll end up with just the chassis (uppers/lowers) ... an empty fork if you will.
> 
> ...


Hey I recently got one of these tools. Digev - if you have time could you explain what is your procedure for burnishing? What kind of oil do you suggest? Supergliss is a bit hard to sorce in the US. Thanks for any info.

Sent from my iPhone using Tapatalk Pro


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## jimarin (Mar 19, 2005)

I used maxima assembly lube and it worked fine.


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## nikon255 (Dec 27, 2015)

cesjr said:


> Hey I recently got one of these tools. Digev - if you have time could you explain what is your procedure for burnishing? What kind of oil do you suggest? Supergliss is a bit hard to sorce in the US. Thanks for any info.
> 
> Sent from my iPhone using Tapatalk Pro


fox gold 20. Generally all moves based on rotating. Rotate more than push/pull. My f36 was tight as fcuk. I cant even rotate. Slickoleum just vanished and didnt help. Supergliss was much better (so fox gold should), but still hard work. After few passes it improved. At the end lowers just slide in. Weird feeling


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## digev (Mar 7, 2019)

cesjr said:


> Hey I recently got one of these tools. Digev - if you have time could you explain what is your procedure for burnishing? What kind of oil do you suggest? Supergliss is a bit hard to sorce in the US. Thanks for any info.
> 
> Sent from my iPhone using Tapatalk Pro


You could try what other guys seem to like (Fox Gold, WPL 20WT, Motorex Power Synthetic 5W40, etc ...) whichever is easier to get.

Regarding the procedure, have a look at the previous posts. It's very straightforward, push down and twist slowly then pull up and twist again(always going clockwise). Do it as many times as as necessary.

After each ride wipe the dust/dirt with a soft clean rag from your stanchions and apply 2/3 drops of either WPL forkboost lube or RSP hyper wiper (wait until it goes all around the stanchions) then cycle the fork a few times ... it will get some of the dirt/dust trapped inside the seals, lubricate and reduce stiction. (It works on the dropper post as well). It's a 1mn job and it really makes a difference! Good luck


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## Chris2fur (Jan 13, 2004)

digev said:


> ...After each ride wipe the dust/dirt with a soft clean rag from your stanchions and apply 2/3 drops of either WPL forkboost lube or RSP hyper wiper (wait until it goes all around the stanchions) then cycle the fork a few times ... it will get some of the dirt/dust trapped inside the seals, lubricate and reduce stiction. (It works on the dropper post as well). It's a 1mn job and it really makes a difference! Good luck


I have not personally tried those two products. They may be great. Everything I have tried as a stanchion treatment, save one product, has always ended up attracting more dust than it got rid of in the first place. Finish Line Stanchion Lube is perfectly named for what it does. Great on droppers, too and never a residue to attract dust. It seems to disappear into the pores of the surface coating, but leaving the surface slick. 
https://www.enduroforkseals.com/products/lubricants/suspension-lubes/S10000101.html


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## CaveGiant (Aug 21, 2007)

Chris2fur said:


> I have not personally tried those two products. They may be great. Everything I have tried as a stanchion treatment, save one product, has always ended up attracting more dust than it got rid of in the first place. Finish Line Stanchion Lube is perfectly named for what it does. Great on droppers, too and never a residue to attract dust. It seems to disappear into the pores of the surface coating, but leaving the surface slick.
> https://www.enduroforkseals.com/products/lubricants/suspension-lubes/S10000101.html


Don't you still owe me a bottle of that?

Empty one arrived a few years ago. Said send another...never came =(

Great product though!


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## Chris2fur (Jan 13, 2004)

CaveGiant said:


> Don't you still owe me a bottle of that?
> 
> Empty one arrived a few years ago. Said send another...never came =(
> 
> Great product though!


Yeah, it's a good way to make money and reduce the chance of spillage, though, right? Seriously I'm horrified to hear we never followed through. Email me your info and we'll ship you some on Monday.


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## Dougal (Jan 23, 2004)

digev said:


> After each ride wipe the dust/dirt with a soft clean rag from your stanchions and apply 2/3 drops of either WPL forkboost lube or RSP hyper wiper (wait until it goes all around the stanchions) then cycle the fork a few times ... it will get some of the dirt/dust trapped inside the seals, lubricate and reduce stiction. (It works on the dropper post as well). It's a 1mn job and it really makes a difference! Good luck


If your fork seals are doing their job, you should already have a fine oil coating on your stanchions. This is visible (especially with black) as a glossy film.
If you don't then you're probably due for a lower leg service.


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## CaveGiant (Aug 21, 2007)

Chris2fur said:


> Yeah, it's a good way to make money and reduce the chance of spillage, though, right? Seriously I'm horrified to hear we never followed through. Email me your info and we'll ship you some on Monday.


thanks


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## Novaterra (Jan 1, 2014)

I thought my fork had some tight bushings. Butnow i took out the wjeel and measured the spacing in the fork. 109,3mm. If i cycle the fork through its travel it feels better(less stiction) at the end of the travel. So i'm going to make the hub 109,3. And ifthat doesn't help enough i'm going the other way and get the tool to do the bushings


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## digev (Mar 7, 2019)

Novaterra said:


> I thought my fork had some tight bushings. Butnow i took out the wjeel and measured the spacing in the fork. 109,3mm. If i cycle the fork through its travel it feels better(less stiction) at the end of the travel. So i'm going to make the hub 109,3. And ifthat doesn't help enough i'm going the other way and get the tool to do the bushings


Yeah it's worth checking that first! Nice one


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## CCS86 (Jan 6, 2020)

It's worth mentioning that loading the fork without the wheel installed, is more likely to be pure axial compression. Where with the wheel on and fork installed, you will get side loading due to the head angle. This alone will make the perceived friction very different.

Sent from my Pixel 4 using Tapatalk


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## digev (Mar 7, 2019)

Any idea about a tool to increase the spacing when it's not exactly 110?

OR

Remove some material from the end caps?

Mine is 109.6mm but the DT240 hub is bang on 110mm.

@CCS86: You seem to have the knowledge, the tools and the will to turn an idea into reality in less that 24h 

What do you think is best?


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## CCS86 (Jan 6, 2020)

digev said:


> Any idea about a tool to increase the spacing when it's not exactly 110?
> 
> OR
> 
> ...


Getting an accurate measurement of lower leg width (at the axle) is really tough. Plus, without a good way to measure the same, near the brace, it's hard to take action.

I think that the best way to evaluate hub width for your fork would be the following:

Get the fork in a fully compressed state and hold it there (air cap removed). Then take your wheel and use it to check fork width like a feeler gauge. You can use feeler gauges if there is a gap to quantify, or notice that the forks must spread to fit the hub.

Sent from my Pixel 4 using Tapatalk


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## digev (Mar 7, 2019)

Got it, thanks! I'll do that tomorrow


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## digev (Mar 7, 2019)

I think I found my 3/4mm difference!

Even without measuring, just looking at each side where the end caps go, one is deeper! Make sense?!

On the brake side, it's 24mm wide










The other side is 24.3mm wide



















3/4mm difference on one side matches with the ~109.6mm total spacing (give or take 1mm) instead of 110mm.


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## digev (Mar 7, 2019)

I'll ask Oliver @ Blueliquidlabs if he can come up with a facing tool with a 15mm axle! Something with a way to stop it when you reach the required width.

That kind of tool.









I was talking with Fabien the owner of Fast Suspension a few days ago and he was saying that they see a lot of lowers like that but they can't do anything about it otherwise the customers will loose their warranty. It's easier when it's too far apart (or the hub spacing is too narrow) and you just add a spacer.

He said stretch the lowers appart (and I did) but when you put your wheel back in place and re-tighten the axle it goes back to whatever width it was. It's not horrible and I can definitely live with it but now that I know, it bugs me a little. Just so we're clear the bushings were mega tight anyway ... even with the axle removed. But it could probably be even better (110mm hub with 110mm spacing).

Let's finish the job 100%


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## Gman086 (Jul 4, 2004)

^^Honestly I think the axle spacing is having a bigger affect than the bushing tolerance from what I've seen on Fox forks in particular!

Have FUN!

G MAN


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## CCS86 (Jan 6, 2020)

Gman086 said:


> ^^Honestly I think the axle spacing is having a bigger affect than the bushing tolerance from what I've seen on Fox forks in particular!
> 
> Have FUN!
> 
> G MAN


I would disagree with this.

When you have a fork width mismatch like this, both the upper and lower legs will deflect to find a shared axis for each leg. This will add a bit of radial force against the bushings (from the crown and the brace), which will add a small amount of friction. But, hitting the brakes for example puts wayyyyy more radial force into the bushings.

When a bushing to stanchion fit is too tight, it can create a huge amount of force and friction. Just think about how hard it is to move the tool through the bushing vs the stanchion, for such a minute change in size.

Sent from my Pixel 4 using Tapatalk


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## Chris2fur (Jan 13, 2004)

Dougal said:


> If your fork seals are doing their job, you should already have a fine oil coating on your stanchions. This is visible (especially with black) as a glossy film.
> If you don't then you're probably due for a lower leg service.


Yes, depending not only on the seals, though. Stanchion coatings are not all created equal. Some manufacturers misunderstood stanchion surface finish and got them too smooth on a microscopic level. You, of course already know this but I'm making the point for others with specific regard to Stanchion Lube. Proper stanchion coatings have enough roughness that the micropores retain lube. A highly polished nickel surface will not retain the lube because there are no spaces below the surface to store it. Good seals will wipe them clean--pretty much leave them dry. In these cases, the rider will have to deal with constant surface stiction or use Stanchion Lube pre-ride to mitigate it.

Also, the original post about lubing the stanchions was really about a particular way to clean small particles from the inside edge of the wiper. Applying a drop or two of Stanchion Lube just above the wiper and allowing it to settle, then cycling the fork, will leave a ring of lube that contains small particles lifted from the wiper edge, that can then be wiped off.

But, generally speaking, you are right that proper stanchion coating with good seals and good lube in the fork will leave a very fine coating on/in the stanchion surface and additional lube is not necessary. NOT like the old Fox seals that were, according to Fox, "designed to leak oil in order to lube the stanchion tubes."


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## Gman086 (Jul 4, 2004)

CCS86 said:


> I would disagree with this.
> 
> When you have a fork width mismatch like this, both the upper and lower legs will deflect to find a shared axis for each leg. This will add a bit of radial force against the bushings (from the crown and the brace), which will add a small amount of friction. But, hitting the brakes for example puts wayyyyy more radial force into the bushings.
> 
> ...


My point was I RARELY see tight bushings in Fox forks, certainly not the issue that digev is making it out to be. Axle spacing has been another story...

Have FUN!

G MAN


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## Dougal (Jan 23, 2004)

Gman086 said:


> My point was I RARELY see tight bushings in Fox forks, certainly not the issue that digev is making it out to be. Axle spacing has been another story...
> 
> Have FUN!
> 
> G MAN


Fox recently changed from the loosest bushings in the industry to some of the tightest.


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## digev (Mar 7, 2019)

Yeah Fox is so much better! LOL 

Before
https://streamable.com/fo2mqs

After
https://streamable.com/gi5pwj

credits: #diazsuspensiondesign
Source:https://www.instagram.com/s/aGlnaGxpZ2h0OjE4MDc2OTAyMDQwMTUwNDU2?igshid=10jdxy7csk5p7


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## DMdh (Oct 9, 2019)

Recently saw this video about triple clamp alignment, its incredible the amount of friction it eliminates.

Regarding the method he uses, anyone know if this is better or will you achieve the same result with the normal method of tightening the axle pinch bolts in the correct order and pumping the fork into its travel a little?


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## detsortehul (Jun 25, 2007)

digev said:


> Yeah Fox is so much better! LOL
> 
> Before
> https://streamable.com/fo2mqs
> ...


Links corrected 
https://streamable.com/fo2mqs
https://streamable.com/gi5pwj


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## KoolGrandWizardLuke (Dec 23, 2017)

DMdh said:


> Recently saw this video about triple clamp alignment, its incredible the amount of friction it eliminates.
> 
> Regarding the method he uses, anyone know if this is better or will you achieve the same result with the normal method of tightening the axle pinch bolts in the correct order and pumping the fork into its travel a little?


They achieve different things. Pumping the fork to align the lowers on the hub and axle aligns the lowers to the correct width on the axle/hub.
The method in the video aligns the triple clamps and stanchions square. If the upper and lower triple clamp are not aligned properly then the stanchions will not be parrallel. This is what can create a lot of friction.


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## mike156 (Jul 10, 2017)

Burnished the bushings in my 2018 Lyrik today and it wasn't the improvement others are reporting. I bought this fork last fall as a new take off so it has about 6 months of riding on it.

Before burnishing, the weight of the CSU would over come the friction when a single stanchion was put in a lower. Without a wheel mounted in the lowers, the CSU with both stanchions in would need a little tap to get going but would then continue sliding on it's on. With a wheel mounted, the CSU would slide down smoothly on it's own. 

Actual burnishing, I felt like it was going to ruin the bushing as it's fairly difficult to keep it straight while first starting out. I pulled it out after it made it about half in and you could clearly see a lip had formed in the bushing. In the end though, after getting it all the way through both bushings and back out, both looked smooth again without any lips.

After burnishing... It felt the same as before but it seems like I had a good one to start with. Makes me curious how much this varies from fork to fork.


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## mike156 (Jul 10, 2017)

First ride follow-up and I'm kind of surprised. It was feeling soft around the neighborhood spin so I added two clicks of LSC and a click of rebound (at the original recommended settings by Avy now). Added 2.5psi of air as well. 

Despite that, I used ~10mm more travel then ever before (still have about 20mm left) and it's never felt better. Ride some trails that I really like and have a bunch of everything from rocks, loose shale, steeps, jumps, berms, drops and some crappy climbs in between.

Work done was new seals (Enduro Hyglide), bushing burnishing, and new fluids (but the same type and amount as before). This was on a fork with about 4-5 months on it since it's last fluid change. Kind of curious to see if the seals "break in" and change anything.

As I stated in my last post, I was doubting it was going to be much of an improvement. It could be the seals, lube, or bushings though but between the 3, this fork is feeling noticably better over a fork that already felt great before.


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## nicolasswid (Apr 15, 2014)

On my SID, axle spacing did make a difference.
I found that using a 1.5mm handmade plastic washer helped.
I think it's compensate the fact my stanchions are not parralel.
But friction is variating a lot according how much you tighten the axle, how the washer is placed... If axle is not tightened, the fork twist and it's worst.

To check friction, I remove the top air cap with schrader valve (so no air in the fork), I fully compress, and then lift the fork (with wheel attached). In my case (bad fork), it extends until 30% sag approx when axle spacing good. And to 60% sag with original axle spacing.

Still the fork is not so good... but maybe riding it a lot it will get better.


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## nicolasswid (Apr 15, 2014)

Good news, I managed to repair/improve my SID!
I dissassembled it for the thousands time.
I sandpaper the bushings , then I put a "polish paste" (like a sandy red fine dust) on the bushings and on the burnishing 32.12mm tool. I worked the bushing again and again until the 32.12 tool was moving freely. At this point, I could insert both stanchions in the lower leg and they fell by gravity, smoothly, like the video you sent (without oil seals, without damper, without maxle, and with air piston fully compressed so that it doesnt interfere. With oil seal, it still fall by gravity but a little bit less quick). 
Still the bushings have a layer of plastic (PTFE?) but it is thin. diameter of the bushings is now 32.18-32.20mm approx

Axle spacing measured on lower legs "alone" measured 110.1. When inserting the stanchions, it raised to 111.1 (that mean the unparallel stanchions are deforming the lower legs... so I imagine 111.5mm would be perfect axle spacing for me. 
When the maxle is tightened on the 110mm hub the stanchions stopped to fall freely in the lower legs. So I made a 1.5mm thick washer to have 111.5 mm axle spacing and then the stanchions fall freely into the lower legs.

I assembled the fork, and it is now a totally different fork, really better, NOW it can be called a suspension.
I now use 90 psi (instead of 70 psi before, friction was so high!)

I tried to wet sand the stanchions also (on a small portion) but it was not improving the friction, does not recommend it.


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## digev (Mar 7, 2019)

Cool stuff! Happy for you

Now you're ready to help others in need of the same treatment if you ever hear someone complaining about a similar issue 

Enjoy your next rides! (Thanks for taking the time to post a feedback)


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## nikon255 (Dec 27, 2015)

sandpaper :madman::madmax::nono:


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## CCS86 (Jan 6, 2020)

I think you would be better off trying to bend the stanchions inwards until the lower legs sit at a nominal width.

By spacing your hub, you are accommodating non-parallel (diverging) stanchions, instead of fixing them. Even if friction feels better near the top of travel, it will likely be worse near the bottom.


Sent from my Pixel 4 using Tapatalk


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## Rumblefish2010 (Mar 29, 2012)

Just looked at your calculation of the size up recommendations:

(0.0015"+0.009")/2=0,00525"

I think 0,00525" is 0.1335mm?

(0.0381mm+0.2286mm)=0.1335mm



digev said:


> Fox say correct bushing tolerance is a diametric clearance of
> 
> min: 0.0015" (0.0381 mm)
> max: 0.0090" (0.2286 mm)
> ...


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## PHeller (Dec 28, 2012)

This thread makes me wonder about MRP Ribbon bushings being too tight - lots of complaints about harshness from that fork.


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## digev (Mar 7, 2019)

PHeller said:


> This thread makes me wonder about MRP Ribbon bushings being too tight - lots of complaints about harshness from that fork.


It's easy to find out!

Empty the fork, slide/cycle the CSU into the lowers by hand! It's either smooth or it's not


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## nikon255 (Dec 27, 2015)

position fork upside down and gently push lowers it should slides a bit itself. Kinda scary view for the first time after burnishing


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## nicolasswid (Apr 15, 2014)

You are right. I tried but I did not managed. Those things are rock solid. I put it in a vice and controlled the deformation with caliper... it is so strong it always go back at the exact place If I remember well I moved it 3mm approx. Then I decided it was too risky to force too much and risk to damage the parts, or to bend it too much or in another direction...


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## 294037 (Jun 30, 2006)

PHeller said:


> This thread makes me wonder about MRP Ribbon bushings being too tight - lots of complaints about harshness from that fork.


Yup I've seen several Ribbon's with tight bushings


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## Ole (Feb 22, 2004)

I have now ordered bushing removal/insertion tool and bushing resizing tool with 36.13mm and 36.20mm dies from blueliquidlabs.com, for my Fox 36. I hope to be done with tight bushings forever!


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## digev (Mar 7, 2019)

Ole said:


> I have now ordered bushing removal/insertion tool and bushing resizing tool with 36.13mm and 36.20mm dies from blueliquidlabs.com, for my Fox 36. I hope to be done with tight bushings forever!


Nice one  I'd be surprised if you regret it! Don't forget to lube the bushings while doing it (it just makes it easier) and after.


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## GlazedHam (Jan 14, 2004)

If my memory serves me, one of the suspension tuner who is still around today used to list "custom bushing selected based on the dimensions of your fork" as one of their primary "tuning" benefits. I know that last time I had my 36 rebuilt, the LBS likely just used the first bushings they found in the box.


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## GlazedHam (Jan 14, 2004)

Ole said:


> I have now ordered bushing removal/insertion tool and bushing resizing tool with 36.13mm and 36.20mm dies from blueliquidlabs.com, for my Fox 36. I hope to be done with tight bushings forever!


 For the lazy such as myself, could tell us the approximate cost?


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## ghostbiker (Oct 24, 2018)

GlazedHam said:


> For the lazy such as myself, could tell us the approximate cost?


I believe it´s 140USD for tool.


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## Ole (Feb 22, 2004)

GlazedHam said:


> For the lazy such as myself, could tell us the approximate cost?


Bushing removal tool: 90 USD
Bushing sizing tool with one sizing die of your choice: 140 USD
Each additional sizing die after the first one is 50 USD
The insertion tool is adapted to the central body of the sizing tool. The insertion adapters (hammer pad, clamp and insertion die) are 50 USD
Fox 36 bushings 36 USD


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## digev (Mar 7, 2019)

Ole said:


> Bushing sizing tool with one sizing die of your choice: 140 USD


Yep, that's what I got


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## Ole (Feb 22, 2004)

digev said:


> Yep, that's what I got


I am ordering dies for 36.10, 36.13 and 36.20mm. That way I can work my way up to something that works well for my usage.


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## digev (Mar 7, 2019)

Do yourself a favor and check yours, it's so worth it 


__
http://instagr.am/p/CDCCHWWHhn-/


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## JB450 (Mar 31, 2019)

That insta post is crazy. So much bushing bind.

My fork isn't anything like that, but I'm still making a burnishing tool to check it at my next service. 

Sent from my INE-LX2 using Tapatalk


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## digev (Mar 7, 2019)

JB450 said:


> That insta post is crazy. So much bushing bind.
> 
> My fork isn't anything like that, but I'm still making a burnishing tool to check it at my next service.


You are right, it's the best timing to check those bad boys out!

To be honest, out of all the forks I've done (burnished) they were pretty much all like that 

Pike/Lyrik/Boxxer

But not anymore, now they all run smoooooth! Makes a Huge difference at low speed and you can feel it move freely and kiss the ground as it was intended to. Your hands will thank you


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## JB450 (Mar 31, 2019)

digev said:


> You are right, it's the best timing to check those bad boys out!
> 
> To be honest, out of all the forks I've done (burnished) they were pretty much all like that
> 
> ...


Yeah, I figure there is definitely room for improvement on my revelations.

Sent from my INE-LX2 using Tapatalk


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## digev (Mar 7, 2019)

JB450 said:


> Yeah, I figure there is definitely room for improvement on my revelations.


Only one way to find out


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## digev (Mar 7, 2019)

mike156 said:


> First ride follow-up and I'm kind of surprised. It was feeling soft around the neighborhood spin so I added two clicks of LSC and a click of rebound (at the original recommended settings by Avy now). Added 2.5psi of air as well.
> 
> Despite that, I used ~10mm more travel then ever before (still have about 20mm left) and it's never felt better. Ride some trails that I really like and have a bunch of everything from rocks, loose shale, steeps, jumps, berms, drops and some crappy climbs in between.
> 
> ...


Missed your post somehow! Thanks for the detailed feedback, it should help others  and glad it now feels even better, well ... everywhere 

Have a nice summer!


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## Iranian-Mechanic (May 6, 2004)

I cant get the point

Why dont the manufacturers just make the bushings the right diameter ?
As all the stanchions in a specific fork model are exactly the same diameter right ? Zero tolerance so why should the bushings be different ?


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## JB450 (Mar 31, 2019)

Iranian-Mechanic said:


> I cant get the point
> 
> Why dont the manufacturers just make the bushings the right diameter ?
> As all the stanchions in a specific fork model are exactly the same diameter right ? Zero tolerance so why should the bushings be different ?


Time. Cost. Profit.

The manufacturers don't actually care. They only care about the above three things, but not necessarily in that order.

Sent from my INE-LX2 using Tapatalk


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## Iranian-Mechanic (May 6, 2004)

JB450 said:


> Time. Cost. Profit.
> 
> The manufacturers don't actually care. They only care about the above three things, but not necessarily in that order.
> 
> Sent from my INE-LX2 using Tapatalk


Hmmm thing were better back in the good ol days when manufacturers were bikrs themselves like Ritchey like Synyard like Joe breezer...& so on

They had the love & passion of biking besides the will to profit and i believe those kid of peoples love of biking was more power full than their love on money and profit......

Nowadays....because of the big companies no passionate small manufacturer could compete .........i call that warmartism in bike industry and have written an article on that subject in my personal website back in 2015 but unfortunately its not in English and in my local language......


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## mike156 (Jul 10, 2017)

Manufacturing tolerances is why.

Its a near net shape cast magnesium piece with minimal machining. The machining they do is likely just done on a basic mill center, which can be extremely accurate but when it's setup to do hundreds of pieces a day, you usually sacrifice accuracy for throughput.

They also likely run them slightly on the tight side to begin with to ensure all bearings are a press fit so you don't have a bushing bore that's too big and the bushing falls out.

Then you get tool wear that will have the bore shrink as you machine more pieces between tool changes.

They also probably run them a little tight as they won't have to warrantee a sticky fork, but a fork that clicks from overly loose bushings probably would be a warrantee repair.

The bushings themselves could be a source of variance.

As I mentioned, mine wasn't very tight at all and I didn't expect this to have much impact. Even in a fork that didn't seem to need it though, it still made a noticable improvement. I do think part of it was the fluid change. After almost three months of riding, I've opened compression damping up one click last week after the fork started feeling a little more harsh again. Probably needs the fluids changed again on the spring side.


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## Dougal (Jan 23, 2004)

Iranian-Mechanic said:


> I cant get the point
> 
> Why dont the manufacturers just make the bushings the right diameter ?
> As all the stanchions in a specific fork model are exactly the same diameter right ? Zero tolerance so why should the bushings be different ?


Because zero tolerance is impossible.

Fork bushings used to be loose (esp Fox) but they've tightened them up hugely to get better stiffness numbers.

Also bushings naturally resemble an egg shape. It's difficult to get a split ring perfectly round.


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## Iranian-Mechanic (May 6, 2004)

Dougal said:


> Because zero tolerance is impossible.
> 
> Fork bushings used to be loose (esp Fox) but they've tightened them up hugely to get better stiffness numbers.
> 
> Also bushings naturally resemble an egg shape. It's difficult to get a split ring perfectly round.


Thank You very much again Mr. Dougal 
But i mean they can calculate the tolerance cant they ? thay have plenty of precise machinery & plenty of million dollar CAD/CAM softwares & and plenty of good engineers......Dont think calculation a tolerance between two sliding parts would be a hard job for them would it ?

Me my self for example when servicing cup & Cone hubs i have a standard for my self to set the anchor point of the axle to have 0.2 mm of tollerance between the two sides i mean if one side is 5 mm the the other should be between 4.8 & 5.2










and it takes my a couple of hours to reach that standard opening & closing & Tightening & loosening & measuring &.....

Also for other works i have similar standards that take a huge amount of my time to achieve but in the manufacturing process with that amount of technology equipment & possibilities i think its a matter of willing to do or not to do and profit more on time & resources and labor hours

Its not impossible but maybe it would not be profitable in a world which these things doesnt matter anymore


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## ghostbiker (Oct 24, 2018)

Iranian-Mechanic said:


> ... and it takes my a couple of hours to reach that standard opening & closing & Tightening & loosening & measuring &.....


I would bet the whole for is made in less than your couple of hours. Ain´t nobody got time for precision here, they are in to make money not to pay money to Taiwanese workers for messing around for hour with single fork bushings.


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## Iranian-Mechanic (May 6, 2004)

ghostbiker said:


> I would bet the whole for is made in less than your couple of hours. Ain´t nobody got time for precision here, they are in to make money not to pay money to Taiwanese workers for messing around for hour with single fork bushings.


Well certainly thats mass production done on a production line and all the parts & jobs are standardized also done by machines or several people in the length of the production line

And this is an individual mechanical job done by one person also its not unexpected that i hace to clean the mechanical mess the previous mechanics have done

And the whole is not made in less that a couple of hours in a couple of hours i think they make tens if not hundreds of hubs on the line

But you know what i always thought that people in the manufacturing process & in the after market repair works sacrifice accuracy for time effort & profit 
Its a long while im not that much active over here but seems this phenomenon is in a global scale and doesnt matter if its in a developed or a developing country or part of the globe.....

Seems its more a matter of mindset.....a mindset thats riunning every thing in all fields.....


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## mike156 (Jul 10, 2017)

Cost/Benefit

What would it cost to hold tolerance tighter and what would be the benefit? For a manufacturer, tighter tolerances will drive prices higher more quickly then just about anything else. For this reason, you want the largest tolerances possible while still obtaining your design goals.

Realize they have calculated out those tolerances to the sixth decimal place and know what is ideal. But there A LOT that goes into tolerance stacking and manufacturing capabilities.

Here, take for example a basic 0.500" hole.
Flame cut - +/-0.100
Drill bit - +0.006/-0.001
CNC mill - +/-0.003
Boring - +/-0.001
Reaming - +/-0.0005
Honing - +/- 0.0001

Each step down that list, the equipment cost goes up. The operator ability goes up. The time to run the process goes up. Non-conforming product goes up. Inspection costs go up. Not only does the equipment matter, but the environmental controls matter. Heat management matters. Material quality matters.

The tighter tolerances you hold, the higher the price goes. THIS is (often) what you are paying for between a cheap part and an expensive part. TIME, training and equipment investment.

Will holding 0.0002" tolerances make the product better than 0.005"? If not, don't hold that tighter tolerances. If so, how much better? Will 1 in 5 parts fail at that loose tolerance but 1 in 1000 at the tight tolerance? Probably hold the tighter tolerances then. Or maybe it is 1/1000 vs 1/10,000... Better option is likely just warrantee 10 of them instead of hold the tighter tolerances.


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## mike156 (Jul 10, 2017)

Back to the original topic though...

I pulled the seals to do this originally. But I'm thinking about doing it on a friend's fork that is new. Anybody doing it without pulling the seals?


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## nikon255 (Dec 27, 2015)

I did. Just clean everything well, lube bushings with something good like supergliss and go


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## CCS86 (Jan 6, 2020)

mike156 said:


> Back to the original topic though...
> 
> I pulled the seals to do this originally. But I'm thinking about doing it on a friend's fork that is new. Anybody doing it without pulling the seals?


Good summery on tolerances. I burnished with seals in, and don't see an issue with it, if you are careful.

Also worth mentioning that to get into those tighter tolerances requires multiple processes on the same hole. Maybe drill > ream > burnish.

Just like like costs go up to physically make tight tolerances, they also go up in accurately measuring the features. CMMs and their operators aren't cheap. They probably air gauge the lowers and bushings.

Plus, the act of pressing bushings into bores will always contribute to a degradation of roundness/cylindricity.

I would love to tour the Manitou factory and chat with their process design engineers.

Sent from my Pixel 4 using Tapatalk


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## Dougal (Jan 23, 2004)

Iranian-Mechanic said:


> Thank You very much again Mr. Dougal
> But i mean they can calculate the tolerance cant they ? thay have plenty of precise machinery & plenty of million dollar CAD/CAM softwares & and plenty of good engineers......Dont think calculation a tolerance between two sliding parts would be a hard job for them would it ?
> 
> Me my self for example when servicing cup & Cone hubs i have a standard for my self to set the anchor point of the axle to have 0.2 mm of tollerance between the two sides i mean if one side is 5 mm the the other should be between 4.8 & 5.2
> ...


As the others have said, precision costs money. For people to spend that money requires a benefit. Otherwise your competitors can push out products that work just as well for a lot less money.

With the axle example, I would never pay someone to spend time adjusting cones to 0.2mm. Because it simply doesn't need to be that precise. ~1mm is good enough and you can see that by eye.

There is also no perfect size for bushings. It depends on the final size of your stanchion tubes and the lubricating oil you plan to use. A bushing that was perfectly sized to the stanchion would be unridable as you get a lot of friction and no lubrication as the oil gets wiped off the stanchion. I have done that to see what it was like. Rode badly.
So you need some clearance for lubrication and you need some clearance for flex while riding. If your clearance gets too big it becomes perceptible play when the fork isn't ridden and fork torsional stiffness starts to suffer.

So you have an acceptable window of diameter and ovality also ends up in the same window. If production can stay within that then you're good. Otherwise you get angry customers and lost sales. Fixing bushing issues as warranty later can get very very expensive where fixing a production problem early can be just some staff time.

Every brand I have seen has had bushing issues. Some too tight, some too loose, some oval bushings and one even had oval stanchions (fit one leg, turn it 90 deg and it goes tight, turn it 180 deg and it goes loose again!).

It is clear the whole industry is still getting it right. I've spend a lot of time annoying the Manitou engineers on this topic and their new stuff appears to be dead right.


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## Iranian-Mechanic (May 6, 2004)

Dougal said:


> As the others have said, precision costs money. For people to spend that money requires a benefit. Otherwise your competitors can push out products that work just as well for a lot less money.
> 
> With the axle example, I would never pay someone to spend time adjusting cones to 0.2mm. Because it simply doesn't need to be that precise. ~1mm is good enough and you can see that by eye.
> 
> ...


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## One Pivot (Nov 20, 2009)

Overwhelmingly, fork bushings don't *need* to be resized or burnished. They're sort of good enough. They go for no clunking, and if it binds a little bit, 99% of people wont care. 

But we're forum nerds here, and if you're willing to burnish some bushings, and retune your stack, and go for low friction seals, and use the latest ultra slick oils, and mindfully pick fluids, you can get a uniquely good fork! 

I'm always surprised how many people will ride a rock hard fork that they didnt even bother to adjust the spring pressure. Burnishing a bushing isnt a thing to most. 

Thanks to everyone for posting so much details. I need to finish up my lathe project and make these myself.


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## digev (Mar 7, 2019)

Tolerances/Variations can come from the tubes (stanchions) as well!

The following provider (AMSpec-inc) make stanchions for well known suspension companies such as Fox, Rockshox, SR Suntour etc ... and they state what they aim for:

Tolerance range

Outer / Inner diameter : ±0.02mm
Thickness : ±0.02mm
Straightness : <0.05mm
Roundness : <0.05mm
Concentricity : <0.05mm
Surface Roughness : Ry 0.8~1.6

Source: https://www.amspec-inc.com/msg/Bicycle-Suspension-Fork-Tube.html

You can't do anything about a tube with a 35.02mm OD but you can still «widen» the bushings


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## digev (Mar 7, 2019)

If someone is looking at getting new bushings for his/her 35mm RS, ND Tuned is selling something interesting!

They are made by Igus and don't have any metal parts so even if they wear out they won't damage (metal on metal) the stanchions like the regular PTFE coated ones that typically have a maximum wear surface of 0.06mm vs 0.25mm for the Igus


















They cost 44€ ($50) + shipping

Source: http://ndtuned.com/b2b/index.php?route=product/product&path=63&product_id=121&limit=100

Igus Iglidur J3 specs: https://www.igus.eu/product/18

4 Reasons To Replace PTFE-lined Bushings: https://www.igus.com/info/plain-bearings-replace-ptfe-lined-bushings

we don't care about the weight so it's just down to 3 good reasons


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## digev (Mar 7, 2019)

A few batch of happy forks gliding effortlessly after getting the bushings resized!

https://streamable.com/lcbg7n
https://streamable.com/a025ww
https://streamable.com/96qnwb

https://streamable.com/h7m4wj
https://streamable.com/yygyqf

Credits: cjsuspension & slickandslidesuspension

Not a fork, but even the new Trek SuperCaliber with its IsoStrut shock created in partnership with FOX using the frame as a sleeve (and you've would have guessed ... bushings) is not immune to manufacturing tolerances issues ...

https://streamable.com/f8x465


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## ben_mtb (Feb 23, 2018)

I have a lyrik fork which had some stiction. Not as bad as some of the videos above. When I pushed on handle bars, it needed some weight before moving. Initially I thought it was air spring. I replaced it with push acs3. Still it was not as smooth as air pike or smashpot 36 that I also have.

I removed the seals, damper and spring and tried the test. The fork was moving under its weight, like in the videos, sometimes it needed a small nudge. Then I tried the test with a hub, and fork stopped moving under the weight.

I measured the hub opening. It was about 109.5mm, the hub was slightly wider than 110mm. Till this point I was thinking about replacing this fork. So I just cut about 0.5mm into one side of the lowers, then assembled the fork. It made a huge difference. Now its almost as smooth as smashpot 36 fork that I have. It still may benefit from bushing work, but for now I'm happy.

Thanks to everyone who contributed to this thread!


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## Dougal (Jan 23, 2004)

digev said:


> Tolerances/Variations can come from the tubes (stanchions) as well!
> 
> The following provider (AMSpec-inc) make stanchions for well known suspension companies such as Fox, Rockshox, SR Suntour etc ... and they state what they aim for:
> 
> ...


That's a different company to the one making stanchions for RS, Fox and others recently. But I know these companies can run several vendors for any one product. Keeps the industry honest.

Until recently I would have told you that every stanchion from a reputable manufacturer measured into a +0 and -0.02mm window. But I have seen three absolute shockers.


One company had 35mm tubes and bushings which were undersize to the point a 35mm bushing tool just would not even look at going in.
One fork from another company had both ovalised bushings and ovalised stanchions. Lowers were loose enough to knock in a fore/aft direction on each leg, but turn the lowers 90 degrees and the play would disappear!
One fork last week had a stanchion 0.02mm smaller than the other. This is enough variation to complete screw up the press-fit into the crown. But we only found it during a bushing resize. Same leg was a good fit on one tube and knocked on the other.


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## digev (Mar 7, 2019)

ben_mtb said:


> I have a lyrik fork which had some stiction. Not as bad as some of the videos above. When I pushed on handle bars, it needed some weight before moving. Initially I thought it was air spring. I replaced it with push acs3. Still it was not as smooth as air pike or smashpot 36 that I also have.
> 
> I removed the seals, damper and spring and tried the test. The fork was moving under its weight, like in the videos, sometimes it needed a small nudge. Then I tried the test with a hub, and fork stopped moving under the weight.
> 
> ...


Cool info, thanks for sharing it 

How did you «cut» the (15x31) torque cap contact surface please?


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## digev (Mar 7, 2019)

Dougal said:


> That's a different company to the one making stanchions for RS, Fox and others recently. But I know these companies can run several vendors for any one product. Keeps the industry honest.
> 
> Until recently I would have told you that every stanchion from a reputable manufacturer measured into a +0 and -0.02mm window. But I have seen three absolute shockers.
> 
> ...


Always good to hear about your experience because you see a lot more stuff than we do 

I guess it's worth checking those variations with a «proper» caliper to understand where they come from. Either alignment or fit can definitely impact the performance! It's not that difficult to double check but pretty sure 99% of riders think it's «correct» because they are reputable companies or don't even think about the chassis and go straight to the internals (let the tail chasing begin) ... I was one of them up until recently so I should know 

If you've ridden long enough you know some forks feel *special* (same year / same model)! that could well be the explanation


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## david31 (Jun 16, 2020)

digev said:


> Cool info, thanks for sharing it
> 
> How did you «cut» the (15x31) torque cap contact surface please?


Curious about this too--the other side dropout definitely makes it a little harder

My guess would be a custom 15mm/9/16" diameter shank extension end mill holder to hold a 25mm/1" end mill for plunge cutting

Holding the lowers probably isn't too bad on the round sections with some v-blocks. Indicate the hub surface flat and indicate on the axle bore if you want to be precise

I'd assume the OEMs have custom tooling for this so they can machine everything in one operation to cut cost though


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## ben_mtb (Feb 23, 2018)

digev said:


> How did you «cut» the (15x31) torque cap contact surface please?





david31 said:


> 25mm/1" end mill for plunge cutting


Nothing fancy like that. I actually used 100 grid sand paper cut to a size of a washer. I took 3/8 threaded rod, and fixed the sandpaper between nuts, backed by the washer. And attached the rod to a drill. I had to round the nuts to make them pass through axle hole. The other fork lowers keeps the rod perpendicular. Two sets of sand papers were able to make 0.5mm cut.  If I was taking my time, I would 3d print two "bushings" and thread them onto the rod.

Yeah... this was a second hand fork that came with hc97 damper. I replaced air spring with acs3 coil. And with all that it was riding like average air fork. After removing the friction it feels great, like how any coiled fork with good damper should feel. I just came from a ride, it erases the rock gardens now. I ordered some Supergliss from shockcraft to see if it can get even better 

Like race tech's book or any other pros (on this forum) say - the first thing that should be addressed is friction. But this thread and videos really drove the point home for me. :thumbsup:


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## digev (Mar 7, 2019)

ben_mtb said:


> Nothing fancy like that. I actually used 100 grid sand paper cut to a size of a washer. I took 3/8 threaded rod, and fixed the sandpaper between nuts, backed by the washer. And attached the rod to a drill. I had to round the nuts to make them pass through axle hole. The other fork lowers keeps the rod perpendicular. Two sets of sand papers were able to make 0.5mm cut.  If I was taking my time, I would 3d print two "bushings" and thread them onto the rod.
> 
> Yeah... this was a second hand fork that came with hc97 damper. I replaced air spring with acs3 coil. And with all that it was riding like average air fork. After removing the friction it feels great, like how any coiled fork with good damper should feel. I just came from a ride, it erases the rock gardens now. I ordered some Supergliss from shockcraft to see if it can get even better
> 
> Like race tech's book or any other pros (on this forum) say - the first thing that should be addressed is friction. But this thread and videos really drove the point home for me. :thumbsup:


Great stuff! Simple DIY yet effective, thanks for sharing the design 

I wonder if somehow you could use the stock 15mm axle and add a few bits to it ... but anyway, the end result is what matters and you just proved it 

The feeling of the fork after removing a fair amount of stiction/friction is sooo enjoyable and that's really how it should have felt in the first place! Tracking the ground smoothly and letting the spring and damper do their job ... it grows on me every time I ride it 

Not many people get to experience the difference unless they get the *special treatment* done by a suspension specialist but it's usually done with other stuff as well so they might not realize how much of an impact all this had on the overall feel and performance!

Glad to hear this thread is inspiring other riders and you are getting stocked on the new «feel» because it was such an eye opener for me ... it had to be shared 

Thanks to all the other contributors as well for making it accurate and interesting 

To all of you reading this! If you feel your fork isn't compliant or harsh especially over small bumps (possibly due to excess force required to overcome stiction), do yourself a favor and check the bushings clearance and lowers spacing and if necessary/required get it done or do it yourself but don't let a few mm or tenth of a millimeter (in case of the bushings) mess with the joy of riding your bike!


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## rstark18 (Apr 10, 2006)

I guess the new Fox floating axle will eliminate the lowers not being in exact tolerance with the hub flange.


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## digev (Mar 7, 2019)

rstark18 said:


> I guess the new Fox floating axle will eliminate the lowers not being in exact tolerance with the hub flange.


Absolutely


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## Dougal (Jan 23, 2004)

I think you guys are barking up the wrong tree with axle and hub modifications.

If bushings are burnished to the right clearance then +/- 0.5mm at the hub simply won't matter. 
If you are concerned about fork alignment then you should always check how it slides with a hub and wheel installed. 

Machining out dropouts is more likely to put the stanchions out of line than into line.


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## CCS86 (Jan 6, 2020)

I would much prefer to modify or remake an axle spacer, than to machine the fork lower, if there was really a discrepancy there.

It would also be important to measure the dropout width at full topout and bottom out (without any force left acting on the fork), to make sure you have a complete picture of where the fork legs "want" to be.


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## digev (Mar 7, 2019)

Dougal said:


> I think you guys are barking up the wrong tree with axle and hub modifications.
> 
> If bushings are burnished to the right clearance then +/- 0.5mm at the hub simply won't matter.
> If you are concerned about fork alignment then you should always check how it slides with a hub and wheel installed.
> ...





CCS86 said:


> I would much prefer to modify or remake an axle spacer, than to machine the fork lower, if there was really a discrepancy there.
> 
> It would also be important to measure the dropout width at full topout and bottom out (without any force left acting on the fork), to make sure you have a complete picture of where the fork legs "want" to be.


I get what you mean guys because the variations (no matter where they are) will eventually all end up impacting the bushings clearance first! So burnishing is a safer and more «generic» way to sort all this in one go!

But just for the sake of knowing, don't you think that getting the legs parallel again *could* improve the overall performance of the fork «even more»? Or that's just marginal gains? Because you can't leverage many improvements on the chassis but it could be one of them and they all add up in the end!

Can this have an impact on seals (create more friction) on the air shaft or the damper shaft because they are attached at the bottom of the lowers but the top is traveling inside the stanchions and even if the bushings aren't a problem anymore after burnishing, those 2 parts will not end up being parallel at some point while moving into the travel?


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## CCS86 (Jan 6, 2020)

digev said:


> But just for the sake of knowing, don't you think that getting the legs parallel again *could* improve the overall performance of the fork «even more»? Or that's just marginal gains? Because you can't leverage many improvements on the chassis but it could be one of them and they all add up in the end!


Absolutely.



digev said:


> Can this have an impact on seals (create more friction) on the air shaft or the damper shaft because they are attached at the bottom of the lowers but the top is traveling inside the stanchions and even if the bushings aren't a problem anymore after burnishing, those 2 parts will not end up being parallel at some point while moving into the travel?


I wouldn't worry much about that. There is generally a little bit of clearance between the shaft foot and the lower leg. So when you install it and tighten it down, it is generally in an unflexed orientation. So, making sure that the fork legs don't get put in bending during wheel installation, would be a good thing not a bad thing.


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## CCS86 (Jan 6, 2020)

Only days after saying I would prefer to modify axle spacers, I found myself modifying my new Mezzer fork 

I pulled the wheel to check the dropout width of my fork and found it a full 1mm below the boost 110mm spec; where my total hub width was right on the money. So, it made sense to fix the out-of-spec component.

The paint seemed extra thick in the axle flange area. So, I first attempted to chisel off the paint. It has flaked right off on a RS fork, but it was very well bonded.

3D printer to the rescue again. I created a cool 2-piece printed tool that works to deck both sides of the axle flange (one at a time), while accurately centering on the other side. You just use adhesive backed sandpaper to provide the cut. I ended up having to cut significantly past the paint and into the metal to achieve the proper width. But the end result was great.

Getting an accurate measurement of the dropout width is a little tricky. I think the best option is to use inside spring calipers, like this: https://www.amazon.com/General-Tools-454-6-Calipers-Opening/dp/B00004T7SB/

You start with them set slightly narrow, and "tick tock" them between the dropouts, slowly increasing the width until just before the "tick" stops. Keeping the slightest bit of freeplay in there helps to ensure you aren't actually spring loaded up against the surfaces. Once you have them set to match the dropouts, you can measure your inside caliper with a set of digital / vernier calipers (using the same technique).

I also think it is worth checking the width with the fork topped out and bottomed out, to see if it changes much. You need to get the fork into that bottom out position without leaving an outside force acting on it, which could be bending the assembly. Usually holding the air valve open while you bottom the fork will keep it pretty deep in the stroke.

If anyone is interested, I could make a custom version of this tool from a few photos and measurements from your fork dropouts.


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## digev (Mar 7, 2019)

CCS86 said:


> Only days after saying I would prefer to modify axle spacers, I found myself modifying my new Mezzer fork
> 
> I pulled the wheel to check the dropout width of my fork and found it a full 1mm below the boost 110mm spec; where my total hub width was right on the money. So, it made sense to fix the out-of-spec component.


LOL 

What you did seems great and super clean! Imagine those with 3/4mm difference (me) or even up to 5mm like the comment from a week ago ... it does make sense to try and fix the out-of-spec component indeed IMO. Yes resizing the bushings will take care of *most* of the domino effect and you could probably stop there, but *if* the spacing has an impact ... why not finish the job and make sure everything is right! I've got a set of DT 240 and they are dead accurate at 110m as well. I don't know if you want to sell your tool or else but I would definitely be interested as it seems simple enough to do the job properly and make sure you've done everything (along with bushing resizing if necessary) to reduce frictions coming from misalignment and tight tolerances!

Great job, well done ... and thanks for sharing your ideas and experience


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## Dougal (Jan 23, 2004)

CCS86 said:


> Only days after saying I would prefer to modify axle spacers, I found myself modifying my new Mezzer fork
> 
> I pulled the wheel to check the dropout width of my fork and found it a full 1mm below the boost 110mm spec; where my total hub width was right on the money. So, it made sense to fix the out-of-spec component.
> 
> The paint seemed extra thick in the axle flange area. So, I first attempted to chisel off the paint. It has flaked right off on a RS fork, but it was very well bonded.


Did you check for parrallel before that and sliding both with and without the hub in place?

I'm sure you did. But all the people who are modifying forks never mention checking if they have binding issues at different hub widths first.


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## CCS86 (Jan 6, 2020)

Dougal said:


> Did you check for parrallel before that and sliding both with and without the hub in place?
> 
> I'm sure you did. But all the people who are modifying forks never mention checking if they have binding issues at different hub widths first.


Parallel between which features?

I checked for parallel between the dropout flange faces. There was a little bit of error, but they were pretty close. The tool I made definitely improved it.

Sliding friction is tough to check without gutting the fork. Do you really think there is potential that sliding friction ever drops by prying the lowers apart, forcing them from their natural resting position, in assembly with the CSU? I suppose it's possible that if the stanchions were parallel, but the lowers ran narrow towards the bottom, the hub could help deform the lowers straight, instead of letting the stanchions do the work.

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## Dougal (Jan 23, 2004)

Parallel upper and lower tubes.

Meaning. Are the lowers more parallel with unmodified dropouts splayed to fit a 110mm hub vs clearanced.

Because the biggest potential for misalignment in a casting is the brace. Which comes right when the fork is flexed to fit a standard hub. If you modify the dropouts you're potentially locking in misalignment which should be cured by just installing the hub.

from the Shockcraft mobile typewriter


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## CCS86 (Jan 6, 2020)

Dougal said:


> Parallel upper and lower tubes.
> 
> Meaning. Are the lowers more parallel with unmodified dropouts splayed to fit a 110mm hub vs clearanced.
> 
> Because the biggest potential for misalignment in a casting is the brace. Which comes right when the fork is flexed to fit a standard hub. If you modify the dropouts you're potentially locking in misalignment which should be cured by just installing the hub.


Okay, that was my line of thinking too.

Stanchions are relatively easy to check using the same spring inside caliper approach. I found my stanchion to stanchion distance only varied about 0.003" from the crown to the very tips.

The lowers are seemingly much harder to check. The critical geometry is the composite cylinder of the (installed) upper & lower bushings. The outside of the leg castings is not likely to be a good analog for this.

Short of bringing the lowers to my shop, and using a long probe on our Romer CMM inspection arm, or having a set of un-installed, perfectly straight 37mm tubes to project the geometry out to where I can measure; I'm not sure how else I could do it with reasonable accuracy.

Maybe that just leaves you with gutting the fork (IRT, air spring, damper, dust seals, all removed) and checking with feel. Using a fine threaded, 2-part axle stand-in could help you quickly find the hub width that felt best. Then you could modify the fork until that matched the 110mm spacing.

I had a fresh set of lowers and CSU ready to go on my fork, so modifying the original lowers didn't bother me much. I will definitely explore this idea before messing with the new ones, asI have already found the bare lowers alone are ~108mm wide, but increase to 109.2mm once the CSU is inserted.


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## mike156 (Jul 10, 2017)

Air gauge those bad boys, lol.

Otherwise, the feel method is pretty telling. What Dougal is taking about is exactly what I saw. The friction was lower once I mounted a wheel in the fork. It was clearly moving things into better alignment.

The casting could be several mm out of parallel, but if it was fixtured with a 110mm spacer in the hub when the bushing machining happened, everything would then be straight when you mount a hub.

Maybe an effective way to do this would be too machine a spacer at like 105mm and then use some washers to shim it out until you find the lowest friction width. From there, Match up either the fork or the hub to that width.

My DT350 hub was dead on 110.0 as well.


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## Dougal (Jan 23, 2004)

I say confirm stanchions are parrallel (they almost always are) and then a dry sliding test with and without the hub will tell you.

Spring and damper shafts can usually be disconnected and slid up out the way enough for a quick check without stripping the whole fork. Of course these tests are best done without wiper seals. But don't remove them unless you're replacing them.


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## CCS86 (Jan 6, 2020)

Like I mentioned, my new CSU showed about 0.003" of parallelism error (viewed from the front), but a very subtle push with my hands got this to zero.

I agree with Dougal, especially in this Mezzer, the dust seals are hard to remove without damaging. They are actually a pretty kick-ass design. I managed to make a 3D printed tool that let me extract them without damaging them (no contact with the inner or outer seal lips).

From there, I fixtured the bottom of one fork leg and left the other floating. The roughly 0.8mm change in dropout width when inserting the stanchions is very visible. I decided that the tendency of the stanchion ends to fetch up on the second bushing is probably my best metric for ideal hub width.

In this video it is pretty clear, when you deform the lowers into a certain position, there is a sweet spot that lets the stanchions slide right in. That should be the ideal lower leg position. Getting an accurate measurement of what that width is, then using the 110mm hub as the fixed parameter, I can see how much material to remove on the dropout. New threaded length setter/checker on the 3D printer now.


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## link1896 (Jul 13, 2007)

Great discussion people. 

CCS86, what profile for your burnishing heads did you settle on? I plan on making some. 

It took me reading this thread half way though before I realised the tool was just a turned lump of steel at the desired final bushing ID, and not a honing tool. 



The IGUS bushings look interesting.


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## CCS86 (Jan 6, 2020)

This tool worked really nicely.

With the fork fixtured like the video above, stanchions hung up entering the second bushings, I installed the tool loosely. Then, slowly I expanded the tool until the CSU dropped in under its weight. Tool gets removed and measured for width.

I also started with the lowers over expanded and worked inwards, to bracket the best range. Ideally, the tool measures at or below the width of your hub, leaving you room to remove some material.

I was happy to find that the best width occured just as all the paint cleaned off the dropouts on the lowers. This goes with my hunch that the lowers are bare when fixtured with a 110mm spacer for machining the bushing bores. A nice flat, bare aluminum flange to land the wheel hub against is going to give you a stiffer connection and fork assembly.










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## digev (Mar 7, 2019)

CCS86 said:


> In this video it is pretty clear, when you deform the lowers into a certain position, there is a sweet spot that lets the stanchions slide right in. That should be the ideal lower leg position. Getting an accurate measurement of what that width is, then using the 110mm hub as the fixed parameter, I can see how much material to remove on the dropout. New threaded length setter/checker on the 3D printer now.


Very well done ... from the video (Proof of concept) to the checker (to find the sweet spot and measure how much material needs to be removed) and the facing tool (to do the job) ... woow, brilliant


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## CCS86 (Jan 6, 2020)

link1896 said:


> CCS86, what profile for your burnishing heads did you settle on? I plan on making some. .


I ended up putting a 10mm nose on the head at 34.9mm (0.1mm under nominal). This definitely helped get the tool started straight.

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## link1896 (Jul 13, 2007)

Thanks dude. 

Sharp transition that makes a cut?


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## CCS86 (Jan 6, 2020)

link1896 said:


> Thanks dude.
> 
> Sharp transition that makes a cut?


I did a very shallow transition (forget the angle off the top of my head), with fillet blends. You don't want to make a cut with a burnisher, just use pure compressive force to plastically deform the high spots.

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## link1896 (Jul 13, 2007)

got it, thanks a million.


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## Ole (Feb 22, 2004)

Ole said:


> I have now ordered bushing removal/insertion tool and bushing resizing tool with 36.13mm and 36.20mm dies from blueliquidlabs.com, for my Fox 36. I hope to be done with tight bushings forever!


Well, that took it's sweet time to get to Norway. I guess Covid-19 and Trump dismantling USPS didn't help...

I was given an old VAN36 that has been so neglected that the coating has worn off on one leg. The lower legs fall off with no recistance. But even so, the 36.10mm die was quite hard to get in. Is that really where the tolerances are?

My 2020 36 started out very nice, and remained so for several months before becoming "bindy" despite servicing the lowers. Roughing up the surface of the bushings with 800 sandpaper helped a lot on the binding, but became slow instead. After 10 or so rides, the tolerances improved and it would be quite nice. But it still would only be nice a couple rides before getting harsh again. I then used a syringe with a ball pump needle to inject oil past the dust vipers and basically fill the foam ring area with oil before each ride, but it would still get harsh a bit into the ride. I speculated gravity would move the oil past the bushing whenever the fork moved. I tried lifting the dust vipers and foam rings and filling that space with alcohol, just to see how tight the busings were. The alcohol didn't drip down when the fork was still. So not really any clearance to speak of, and no oil would seep into the top when stored hanging from the front wheel. I then got the old hacksaw blade out and cut two grooves in the upper groveless bushings, one in the front, one in the back. Filled up the top with oil instead of alcohol and tried compressing the fork again. Lots of air and oil would wheeze in and out of the grooves, and now also easilly seep into the top during storage. The next two rides were awesome as long as I rode hard, I haven't had a fork that nice since the old VAN36 days. The next step is to try the 36.10mm die on it to hopefully get it to perform well even when not charging all the time.

I have also heard that Kashima is not so good at bringing lube oil up past the bushings, oil doesn't adhere to it so well. Any thoughts on this? My sons' decade old RockShock forks have much less breakaway force than any Kashima fork I've ever had...


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## smudge (Jan 12, 2004)

Ole said:


> Well, that took it's sweet time to get to Norway. I guess Covid-19 and Trump dismantling USPS didn't help...
> 
> I was given an old VAN36 that has been so neglected that the coating has worn off on one leg. The lower legs fall off with no recistance. But even so, the 36.10mm die was quite hard to get in. Is that really where the tolerances are?
> 
> ...


Just another area to look...when I tore mine down last month I found that the bushing in the neg plate was binding on the air shaft. I made a bullet tool that was +0.002" oversize and pressed it through when reinstalling the plate on the shaft. It made a surprising difference despite the small surface area of that bushing on the shaft.


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## ghostbiker (Oct 24, 2018)

Ole said:


> I have also heard that Kashima is not so good at bringing lube oil up past the bushings, oil doesn't adhere to it so well. Any thoughts on this? My sons' decade old RockShock forks have much less breakaway force than any Kashima fork I've ever had...


Yes, Kashima is not good, it´s too smooth with pores filled in, so there is nowhere for oil to stick. But it´s low friction if you like running your forks dry lol.


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## Nick_M2R (Oct 18, 2008)

Have a set of Lyriks that have some bushing bind going on, and have been in touch with Oli at Blue Liquid Labs, and will be getting one of his fine bushing burnishing tools.

From this thread, seems the nominal tool width for Rockshox 35mm forks is to go a 35.07mm tool. I note that some have also used a 35.1mm tool as well. 

Should one find the improvement acceptable once burnished with the 35.07mm tool, would there be no reason to go up to the 35.1mm tool, other than wanting it to be a looser fit? Given burnishing involves plastic deformation, once the tool is pushed through it should hold the larger size, but I believe mentioned some posts back, is that the bushing will shrink back slightly (From what I presume is the metal backing slightly expanding and contracting)

Will like go for the 35.07 and 35.1, but given ill be having these sent to Australia, want to make sure I order correctly, given the International post is both long/bit of a crap shoot at the moment


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## digev (Mar 7, 2019)

I'd say you're safe to go with the 35.1mm as they do shrink back a little and that much clearance is still acceptable! Now as to how much difference it makes, no idea. In reality it depends on «your» fork as they all have subtle variations on different spots but the generic approach of burnishing up to a certain diameter so it fixes almost all of them at once is probably the easiest and still safest bet.

+.1mm seems to be a reasonable

I did mine (and a bunch of other RS) with the +.07mm and it did make a difference each and every time but if I had to buy one again I would probably push it up to +.1mm! Doesn't sound like much but it's a 30% difference ... now does it stay 30% wider once the bushing material flex back, I don't know 

PS: Oliver is working on a facing cutter tool to be used with the burnishing tool handle (to make it 2in1, great) + gauging tool to make sure the legs are parallel once placed onto your hub. The goal is to find the sweet spot where the CSU/stanchions travel inside the lowers with the least bending possible (If needed, of course)

Like @CCS86 did


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## digev (Mar 7, 2019)

smudge said:


> Just another area to look...when I tore mine down last month I found that the bushing in the neg plate was binding on the air shaft. I made a bullet tool that was +0.002" oversize and pressed it through when reinstalling the plate on the shaft. It made a surprising difference despite the small surface area of that bushing on the shaft.


I tend to agree with that thinking! Anything traveling inside something else could be a potential area for improvements 

That's not surprise that coil forks feel more supple and track great, less stiction/friction can only improve the sensitivity


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## digev (Mar 7, 2019)

ghostbiker said:


> Yes, Kashima is not good, it´s too smooth with pores filled in, so there is nowhere for oil to stick. But it´s low friction if you like running your forks dry lol.


I've had Kashima forks since they got released many years ago and the last 36 (3years ago) had the black stanchions and it made absolutely no difference whatsoever (brake away force was the same and I didn't notice any improvement in that regard)! So yeah, Kashima is probably slightly better on paper or in a lab but there's probably many things to fix/improve before getting the benefit of a very slight decrease in friction compared to say ... tight bushings, LOL 

BTW Kashima coating is impregnated with MoS2 (Super low friction coefficient: 0.06) but a good old rub will generate a huge amount of static and dynamic friction, way way wayyyy more than any fancy surface treatment can help with!


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## link1896 (Jul 13, 2007)

digev said:


> I'd say you're safe to go with the 35.1mm as they do shrink back a little and that much clearance is still acceptable! Now as to how much difference it makes, no idea. In reality it depends on «your» fork as they all have subtle variations on different spots but the generic approach of burnishing up to a certain diameter so it fixes almost all of them at once is probably the easiest and still safest bet.
> 
> +.1mm seems to be a reasonable
> 
> ...


I was thinking fancy and making mine with two indexed carbide inserts, with a spigot that extends into the dropout hole on the cutting side, and a drop in shaft located with a bushing at the other face, driven by a cordless drill.

Only way I could make such a tool would be using a Dremel and using aluminium 2011 T6 for the tool. Place the work piece in the mill chuck ( locked in position, cut away then rotate 180) and mount the Dremel to the bed. Getting the angle of the dangle could be challenging.

Other way would be take an existing indexed carbide insert end mill of the right diameter , and drill a hole up the end to make a 15mm plug that goes into the axle hole.

Many ways to skin the cat.

I'll draw something and/or photos soon.

You guys are champions.


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## CCS86 (Jan 6, 2020)

I'm all for cool tools, but unless you have a ton of material to remove, my 3D printed tool with sandpaper does a great job, with very low risk, fork still on bike.

Sent from my Pixel 4 using Tapatalk


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## link1896 (Jul 13, 2007)

something like this, with a locating pin in the middle that locates to a bush placed in the axle hole.


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## piciu256 (Feb 15, 2019)

Does mayby someone here have a 34mm bushing sizing tool to rent/ make? I'm in central EU.


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## digev (Mar 7, 2019)

piciu256 said:


> Does mayby someone here have a 34mm bushing sizing tool to rent/ make? I'm in central EU.


Contact Oliver @ blueliquidlabs, he'll make one for you  (he's shipping worldwide)


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## digev (Mar 7, 2019)

Result: https://streamable.com/lh8y96

Credits: @Goatcyclesnz


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## digev (Mar 7, 2019)

It's cool to see them pop out everywhere, homemade or purchased ... they'll make some riders happy!


































PS: I get PMs regularly about where someone could find a shop/tunner to do the «special treatment» to their fork!

If you have a shop and can do it for customers please leave a message with your info so people don't have to search around. win-win 

Option 2: Buy one (link left on the very first post of this thread)
Option 3: Make your own
Option 4: Have you friend buy one or make one and borrow it 

No matter the option, your fork will slide effortlessly after that!


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## johnsogr (May 31, 2009)

Noob here, but find this very interesting. Have a RS Yari, if I buy this tool, do I just force it into the lowers? Are there instructions on actually how to do the “expanding”? Would love to see someone do it on YouTube. thanks for the help!


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## digev (Mar 7, 2019)

johnsogr said:


> Noob here, but find this very interesting. Have a RS Yari, if I buy this tool, do I just force it into the lowers? Are there instructions on actually how to do the "expanding"? Would love to see someone do it on YouTube. thanks for the help!


Yes you just push and twist at the same time, once you've gone trough both bushings you pull and keep twisting (very simple yet very effective)


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## johnsogr (May 31, 2009)

Sweet! So I can just email Oliver - thank you!


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## digev (Mar 7, 2019)

johnsogr said:


> Sweet! So I can just email Oliver - thank you!


Cool


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## Nick_M2R (Oct 18, 2008)

Mines on the way, very excited! Sitting in Chicago waiting for the long trek down to Australia.....

Will post up my fork results when it arrives!


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## digev (Mar 7, 2019)

Nick_M2R said:


> Mines on the way, very excited! Sitting in Chicago waiting for the long trek down to Australia.....
> 
> Will post up my fork results when it arrives!


Keep us posted 

Have a safe trip back home


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## dlocki (Mar 30, 2017)

digev said:


> It's cool to see them pop out everywhere, homemade or purchased ... they'll make some riders happy!
> 
> 
> 
> ...


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## digev (Mar 7, 2019)

dlocki said:


> Yep i made that one


HeyHey, Nice

What die diameter did you go for? Happy about the result(s)?


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## dlocki (Mar 30, 2017)

Started with 35.07 on a brand new set of forks so hard to tell. The forks on the bench were a friends. He says they are better. I made a 35.1 yesterday that I am going to try next time I have the lowers off


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## ridiculously (Oct 28, 2020)

I have a RS with about 500 miles on it that has been driving me crazy with the stiction. It would be OK at best for one ride after a clean and lube. 

Eventually, I found this thread and I think I've got it sorted out by "resizing" the bushings. 

I'm rather cheap and don't have access to a machine shop, so after many hours of checking the diameters of different cylinders in my house. I found an impact socket that was just about the diameter I needed. I beveled the edges by spinning it up with a drill and using a file followed by sandpaper. A locking extension was used to make sure the socket was not left behind in the fork legs. 

So far so good. 

Obviously, if you care about your fork and its worth anything, buy or have the proper tool made. But if your ready to abandon your fork and are not sure if a busing resize is the right solution. Maybe this is worth a try.


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## brash (Dec 4, 2018)

digev said:


> BTW Kashima coating is impregnated with MoS2 (Super low friction coefficient: 0.06) but a good old rub will generate a huge amount of static and dynamic friction, way way wayyyy more than any fancy surface treatment can help with!


Very interesting.

This week I had a front tyre get a slash in it, sealant went everywhere including the fork uppers. I gave them a good clean with suspension clean/iso alc and wiped with a microfibre cloth.

The amount of static it produced was insane! That explains it. :eekster:


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## piciu256 (Feb 15, 2019)

Kashima is just a marketing gimmic tho, it does reduce friction a bit and reduce wear, but only without any lubrication, in a fork it's irrelevant as the pores are filled with oil and effectively the surfaces should never touch and flow on a layer of oil instead (if you don't use a degreaser instead of oil when servicing that is  )


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## karpiel (Aug 27, 2010)

What is the chance of completely pulling out the bush if you are a bit heavy handed with the burnishing ?


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## Dougal (Jan 23, 2004)

karpiel said:


> What is the chance of completely pulling out the bush if you are a bit heavy handed with the burnishing ?


Zero. The aluminum grips the lower legs better than the ptfe can grip your tool.

You're more likely to damage the surface than remove the bushing.

Sent from the Shockcraft mobile typewriter


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## digev (Mar 7, 2019)

Credits: @stirlingbikedoctor



















Credits: @lopdog_ws


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## nicolasswid (Apr 15, 2014)

Hello all. About hub width issue, you will be happy to see that the new FOx 38 have a floating axle design to perfectly align the fork and make it smoother. In fact it's like a kind of spacer which can be adjusted to perfectly match hub width. If they done this thing which is heavy and unpractical, it should be useful (maybe more useful on a stiff 38mm than on a 32).

https://www.pinkbike.com/news/first-ride-new-fox-38-fork-pond-beaver-2020.html

https://www.ridefox.com/family.php?m=bike&family=38

https://enduro-mtb.com/en/new-fox-float-38-2021-review/


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## digev (Mar 7, 2019)

nicolasswid said:


> Hello all. About hub width issue, you will be happy to see that the new FOx 38 have a floating axle design to perfectly align the fork and make it smoother. In fact it's like a kind of spacer which can be adjusted to perfectly match hub width. If they done this thing which is heavy and unpractical, it should be useful (maybe more useful on a stiff 38mm than on a 32).
> 
> https://www.pinkbike.com/news/first-ride-new-fox-38-fork-pond-beaver-2020.html
> 
> ...


Yeah, we know 

Floating axles aren't new, they are to MTBs ... on some MX bikes they even have a rear floating axle as well to improve traction etc..

It's cool to see them crossover to MTBikes ... and definitely a good news for hub alignment (therefore friction), like you mentioned 

We probably never seen them before because of the extra weight it adds, but who cares now


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## digev (Mar 7, 2019)




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## Rick Draper (Dec 1, 2009)

digev said:


> Floating axles aren't new, they are to MTBs


Floating axles aren't that new to MTB though, the Fox 36 has always had one since 2005, it just went away when they went to 15mm QR axles then boost spacing. The 40 has always had a floating axle.


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## digev (Mar 7, 2019)

Fair enough! Thanks for the clarification


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## Dougal (Jan 23, 2004)

nicolasswid said:


> Hello all. About hub width issue, you will be happy to see that the new FOx 38 have a floating axle design to perfectly align the fork and make it smoother. In fact it's like a kind of spacer which can be adjusted to perfectly match hub width. If they done this thing which is heavy and unpractical, it should be useful (maybe more useful on a stiff 38mm than on a 32).
> 
> https://www.pinkbike.com/news/first-ride-new-fox-38-fork-pond-beaver-2020.html
> 
> ...


My 2000 Xvert Carbon has a floating axle. They are not new and a lot of 20mm forks used them from then to now. Including every 20mm axled manitou fork.

It is the 15mm axle standard that didn't have a stiff enough axle so needed to clamp against the dropouts for stiffness. Ironically enough it was Fox who created the 15mm axle because their F32 forks had no spare offset to fit a 20mm.


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## Ole (Feb 22, 2004)

Dougal said:


> The aluminum grips the lower legs better than the ptfe can grip your tool.
> 
> You're more likely to damage the surface than remove the bushing.


I had one bushing partially come loose when I adjusted the size. One side of the split moved up a few mm.


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## nikon255 (Dec 27, 2015)

Ole said:


> I had one bushing partially come loose when I adjusted the size. One side of the split moved up a few mm.


one general rule. More rotation than pushing/pulling.


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## Charlo489 (Apr 23, 2013)

So for those that went ahead and resized their bushings, is it worth it ? My lyrik is pretty sticky, I measured it takes 3.5kg to break the initial friction. Would I see an improvement if I take it to a shop ?


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## pedalinbob (Jan 12, 2004)

Yeah, I'm still contemplating this intervention with my fork, which is definitely sticking about an inch into travel. It gives the fork a very definite platform...and some harshness.

I would think that if the bushing was a bit under sized, the binding would be throughout the stroke.

I thought the inconsistency could be a difference in upper diameter, but the binding occurs in only one leg, regardless of which upper is inserted (that is a good tip, by the way, to isolate the problem).

These inconsistencies are why I'm reluctant to spend over $100 and possibly have no improvement. 
I need to disassemble the fork again (including these seals) to get a sense of the exact nature of the binding...and maybe have the bushings and uppers miked.

I can afford a new fork, but I'm just too darn frugal (thanks mom).
And honestly, dropping $600 on a fork isn't exactly chump change...for me, anyway. 

Bob


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## The_Bob (Jan 16, 2018)

did the work on my Pike Ultimate. Has made a really big difference in the mid and larger sized trail features. The jarring, rattling feeling I was getting is mostly gone. Small, high frequency bumps are still not great, but I'm pinning that on the damper performance.


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## digev (Mar 7, 2019)

pedalinbob said:


> Yeah, I'm still contemplating this intervention with my fork, which is definitely sticking about an inch into travel. It gives the fork a very definite platform...and some harshness.
> 
> I would think that if the bushing was a bit under sized, the binding would be throughout the stroke.
> 
> I thought the inconsistency could be a difference in upper diameter, but the binding occurs in only one leg, regardless of which upper is inserted (that is a good tip, by the way, to isolate the problem).


Sounds like one bushing or one set is tighter or misaligned or slightly out of shape compared to the other side ... (anything is possible)

Because it happens only on one side, binding is definitely worsening the friction (lockout feel)!

Testing/Troubleshooting is key (like you already did) but there's a very good chance you'd solve the issue by resizing the bushings ... so both stanchions can slide freely and simultaneously to get rid of the binding


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## digev (Mar 7, 2019)

The_Bob said:


> did the work on my Pike Ultimate. Has made a really big difference in the mid and larger sized trail features. The jarring, rattling feeling I was getting is mostly gone. Small, high frequency bumps are still not great, but I'm pinning that on the damper performance.


Hey Hey, so you owe your mate a nice dinner 

Have you tried testing with lower pressures in your front tire? Small, high frequency bumps like you described (vibrations/chatter) are easily fixed that way (If your bushings have been sorted)! Or you could say most people put too much pressure in the front tire and it's creating this issue  Either way, it's free, fast and easy to try


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## davidsthubbins (Dec 14, 2009)

So Dougal says Fox has tightened their bushings to get higher stiffness numbers. That raises the question... have any of you that have done this noticed a decrease in stiffness? Less friction is great, but not necessarily at the expense of stiffness.


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## CCS86 (Jan 6, 2020)

Increasing bushing clearance doesn't reduce actual stiffness, just measured stiffness (depending on the testing methodology) because of the added freeplay.

Sent from my Pixel 4 using Tapatalk


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## davidsthubbins (Dec 14, 2009)

CCS86 said:


> Increasing bushing clearance doesn't reduce actual stiffness, just measured stiffness (depending on the testing methodology) because of the added freeplay.
> 
> Sent from my Pixel 4 using Tapatalk


That makes sense, but I'm asking about a feeling. Is there ever a case where increasing the bushing size is felt elsewhere, besides decreased friction? Does the "added freeplay" ever translate to a feeling of decreased stiffness?


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## CCS86 (Jan 6, 2020)

I think it would have to be way excessive before you felt it on trail. Too tight, on the other hand, VERY noticeable.

Sent from my Pixel 4 using Tapatalk


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## mike156 (Jul 10, 2017)

You'd probably hear an overly loose bushing clearance before you felt it? The DVO diamond I had seemed like it was running loose, you could easily feel it had some clearance off you held onto the lower while pushing on it. It would also make a slight climbing noise when lightly loaded. It never felt weird though.


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## The_Bob (Jan 16, 2018)

digev said:


> Hey Hey, so you owe your mate a nice dinner
> 
> Have you tried testing with lower pressures in your front tire? Small, high frequency bumps like you described (vibrations/chatter) are easily fixed that way (If your bushings have been sorted)! Or you could say most people put too much pressure in the front tire and it's creating this issue  Either way, it's free, fast and easy to try


Yup, I owe the man! I run my Minion up front with 20PSI, which I always check before a ride. I've moved over to the Fox 34 now after the Pike debacle and with the same 20PSI and the Fox suggested settings I am very happy. I'm still planning on getting a 34.07mm head for the tool to check the Fox 34 bushings at the first lower leg service :thumbsup:


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## brash (Dec 4, 2018)

Checked my 38’s today after never been quite right. Worse bushing tightness of any fork I’ve owned. Shits me that a $2k fork is this sloppily constructed. 

To top it off, I damaged the damper shaft thread when tapping the footnut with a rubber mallet. Same way I’ve done it for 30+ lower services. This one just seemed to be the one that ruined my day. 

Hoping the thread can be repaired with a run of a tap or I’m in strife. Have a race on Sunday. 

What a day lol.


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## digev (Mar 7, 2019)

brash said:


> Checked my 38's today after never been quite right. Worse bushing tightness of any fork I've owned. Shits me that a $2k fork is this sloppily constructed.
> 
> To top it off, I damaged the damper shaft thread when tapping the footnut with a rubber mallet. Same way I've done it for 30+ lower services. This one just seemed to be the one that ruined my day.
> 
> ...


So they have big lower legs channel to lubricate the foam rings and bushings but they are still too tight! Damn ... at least you know what to do now 

Fingers crossed for your damper shaft thread and good luck for your race


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## brash (Dec 4, 2018)

digev said:


> So they have big lower legs channel to lubricate the foam rings and bushings but they are still too tight! Damn ... at least you know what to do now
> 
> Fingers crossed for your damper shaft thread and good luck for your race


Thanks buddy.

Very simple solution to my fork damper thread, quick run up and down the thread with a die and the footnut goes on nicely now. Dodged a bullet with that one! :eekster: Might invest in the proper fox tool now lol.

As for the bushings, The local suspension centre has a set of 38mm proto tools I've been informed, so I might be the guinea pig to see it's effectiveness.

I was blown away at the stiction, I service some of my buddies forks and give them a quick check before re-assembly and this was the worst one yet. I will say though that the foam rings were very well coated, seems that channel does work pretty well.

Edit

Went back together fine as expected but seems like the low speed rebound adjust or is stuck/broken. The HSR and Lsr don't adjust independently. I've obviously broken something.

I'll race it on Sunday. If it doesn't make it an unridable mess I'll just live with it. Driveway test feels fine, intact a fair bit of my stiction issues were solved by all forks feel great when loaded with slick honey on the wipers.


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## digev (Mar 7, 2019)

brash said:


> ...
> 
> As for the bushings, The local suspension centre has a set of 38mm proto tools I've been informed, so I might be the guinea pig to see it's effectiveness.
> 
> ...


I'd say do it because it might feel better straight after servicing but it will get back to sticky very quickly! You discovered the issue and the solution is around the corner (suspension center with 38.xmm die), it's worth it!


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## digev (Mar 7, 2019)

Before










After










Source: @creationcycles


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## johnsogr (May 31, 2009)

Sweet! I just used my 35.07 tool - how many times did you go through to get them that smooth?


Sent from my iPhone using Tapatalk


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## brash (Dec 4, 2018)

damn that's smooth!

I fixed my damper, in short I am an idiot lol  All is well again. 

Lesson to self, don't service suspension with a 2 year old in the garage.


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## carbonpaul (Mar 12, 2013)

*Pike Burnish Tool*

Purchased the burnish tool for my Pike from Oliver Majewski at Blue Liquid Labs / Blue Liquid Labs | An Oliver Majewski Project

We did a Annandale today and it felt great!

I put the new updated airshaft in my pike recently but even with slickhoney it felt a bit "sticky" but after burnishing all is better.

I noticed when filled with my usual air pressure I was getting full travel too easily and had to increase my pressure by 10 pounds which shows how smooth it is now!

Let me know if you are in the Bay Area and need to borrow the tool.

Paul


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## digev (Mar 7, 2019)

johnsogr said:


> Sweet! I just used my 35.07 tool - how many times did you go through to get them that smooth?


As many times as necessary to make it slide smoothly, there's not a «right» amount of passes/turns ... some are so tight you'll end up pretty warmed up by the end  Happy Burnishing 

PS: lubricate the tool and the bushings between each pass



brash said:


> damn that's smooth!
> 
> I fixed my damper, in short I am an idiot lol  All is well again.
> 
> Lesson to self, don't service suspension with a 2 year old in the garage.


I know exactly what you mean  but it's also super cool to have them around while wrenching (maybe not when messing with dampers) 

PS: Uppers sliding into the lowers under their own weight is the end goal (get it done to your 38 and you'll see ... maybe ask your shop to do a quick before/after recording)



carbonpaul said:


> Purchased the burnish tool for my Pike from Oliver Majewski at Blue Liquid Labs / Blue Liquid Labs | An Oliver Majewski Project
> 
> We did a Annandale today and it felt great!
> 
> ...


Always good to hear about real life experience, thanks Paul for the kind offer


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## FactoryMatt (Apr 25, 2018)

got a Supercaliber with a real tight fox bushing in the frame like the one below. can't wait size it to free up the rear end some.


__
http://instagr.am/p/CE9YxoChoF2/


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## Grins83 (Nov 18, 2019)

Hi all,

First off, thanks to all contributors to this great thread, very informative.

Here's my feedback. I own three 27.5/160mm Suntour Aion forks. First one is great, 2nd one is nice and the last one is harsh with no small bump sensitivity. 

No tight bushings here as each stanchion slides freely in each leg but poor tolerances for uppers and lowers. The stanchions are not parallel, they diverge with a 0.6mm difference from top to bottom.

By means of 2 sets of uppers used independently, I was able to figure out the geometry of the lowers.
There is a 0.26mm mismatch between crown spacing and upper bushings spacing. The lowers are too narrow, generating a lot of friction off the top.

On top of that, there was a generous layer of paint on the lowers (at the axle), similar to what CCS86 described. Things were made still worse with the wheel in place, with 0.5mm interference between hub length and axle spacing.

As I rode this fork quite extensively, thinking it would improve over time, it's now too late for a warranty claim.

What I did, following the great information you guys provided here:
- I tried to improve the stanchions geometry but could only reduce the divergence by 0.1mm. (I dared not push too hard on the stanchions)
- I measured the optimum hub length that would let the stanchions slide almost freely, at least around the sag
- I removed excess paint and then brought axle spacing to optimum

The result is still not great but things have improved very significantly, with the fork now being rideable. 

Thanks again to you all, this thread was an eye opener.


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## spo0n (Nov 7, 2020)

carbonpaul said:


> Purchased the burnish tool for my Pike from Oliver Majewski at Blue Liquid Labs / Blue Liquid Labs | An Oliver Majewski Project
> 
> We did a Annandale today and it felt great!
> 
> ...


on that topic.. anyone know how to reduce friction on those rockshox seal heads? the fox ones always seemed a lot lower friction


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## KoolGrandWizardLuke (Dec 23, 2017)

This problem of upper CSU/stanchion and lower castings, and hub being all different widths is just another reason why Upside Down forks feel so great.
Literally the only critical machining is in the two upper crowns.
The hub width doesn't even matter once you are on an USD fork with 20x110mm axle


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## mike156 (Jul 10, 2017)

Isn't torsional stiffness total **** though on inverted forks, since you have no wheel arch bridge???


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## Dougal (Jan 23, 2004)

mike156 said:


> Isn't torsional stiffness total **** though on inverted forks, since you have no wheel arch bridge???


They are all softer torsionally than conventional. How soft depends very heavily on the axle size and design.


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## KoolGrandWizardLuke (Dec 23, 2017)

mike156 said:


> Isn't torsional stiffness total **** though on inverted forks, since you have no wheel arch bridge???


Yes.

Isn't longitudinal stiffness total **** though on a right way up fork since you have a small diameter tube?
This is much more important as low and medium frequency lateral vibrations reduce traction, increase friction in the suspension system, and cause rider fatigue at the handlebars.

Put it this way. Lateral stiffness is not a concern for me on a modern Manitou Dorado.


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## GlazedHam (Jan 14, 2004)

*repeat*

I posted this early on in the thread, but I'm posting it again because it's really all I have to contribute. In the early, early days of suspension forks ( like 60 to 80mm travel days), I swear one of the still existent suspension tweaking companies advertised "custom fitted bushings" as their main selling point along with different oil and some fresh stickers. Their stuff felt great ...anyone else remember this?


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## mike156 (Jul 10, 2017)

KoolGrandWizardLuke said:


> Yes.
> 
> Isn't longitudinal stiffness total **** though on a right way up fork since you have a small diameter tube?
> This is much more important as low and medium frequency lateral vibrations reduce traction, increase friction in the suspension system, and cause rider fatigue at the handlebars.
> ...


Wouldn't misalignment from torsional loads cause bushing binding at that point though?

I could see an inverted dual crown being reasonably stiff, as obviously it works for MX bikes. But I guess I was comparing apples to apples here and thinking single crown vs. single crown. An inverted single crown seems like it would be about as stiff as a cooked noodle?


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## KoolGrandWizardLuke (Dec 23, 2017)

mike156 said:


> Wouldn't misalignment from torsional loads cause bushing binding at that point though?
> 
> I could see an inverted dual crown being reasonably stiff, as obviously it works for MX bikes. But I guess I was comparing apples to apples here and thinking single crown vs. single crown. An inverted single crown seems like it would be about as stiff as a cooked noodle?


On an Upside Down fork assuming you can keep the axle clamped as a single piece to the lowers then torsional loads act the same as lateral loads. This is where a good axle and clamping design come into play. Not a quick release threaded in design.
The floating axle design allows you to align and clamp the lower constraint exactly square with the uppers.
A torsional load then only acts to apply what is essentially opposing lateral loads on to each fork leg.

The difference is that on a standard fork you will never have the uppers/CSU, fork arch, and lowers at the hub all the same width. The fork arch actually makes the fork bind worse once it's stiffness has been overcome and it flexes heavily.


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## Dougal (Jan 23, 2004)

mike156 said:


> Wouldn't misalignment from torsional loads cause bushing binding at that point though?


Luckily inverted DC forks have both the best lubrication (oil bath bushings, not splash bath bushings) and more bushing separation than conventional forks.

Single crown inverted forks are indeed a terrible idea. Every company that has had a go has given up. But damn do they look good.

Halson Inversion PDS (but this one had slotted uppers and a brace).
Manitou Dorado SC
Marzocchi RAC & Shiver SC
Rockshox RS1
Some fatbike fork I can't remember the name of.
X-fusion.

Some people like noodles, but not enough to pay the bills.


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## FactoryMatt (Apr 25, 2018)

Dougal, 

Any experience with Intend or Bright Performance Shocks Inverted SC forks? just curious. they do look good.


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## Dougal (Jan 23, 2004)

FactoryMatt said:


> Dougal,
> 
> Any experience with Intend or Bright Performance Shocks Inverted SC forks? just curious. they do look good.


None at all. Honestly I don't expect to ever see one down here.


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## digev (Mar 7, 2019)

Read a super interesting study yesterday titled «Edges, clearances, and wear: Little things that make big differences in bushing friction»

While I didn't quit get everything (obviously ) it was still interesting enough to spot the similarities/drawbacks measured by their testing rig (Tribometer)

Examples



> A PTFE bushing with 0.15mm interference initially required 50% more torque than a PTFE bushing with 0.35?m clearance.





> Misalignment sensitivity was studied. Relatively poor performance and large scatter in standard bushings were attributed to misalignment of shaft and bushing axes from inherent over constraint, a radius on the edge of the bushing mitigated these effects and increased wear life by several orders of magnitude.


PDF: http://research.me.udel.edu/~dlburris/papers/JA24.pdf

Hope you learn a thing or two  Happy reading!


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## nicolasswid (Apr 15, 2014)

OK, just some help to fine tune hub width.

Remove air of the fork.
Turn your bike upside down. Loosen the axle. Normally there should be a gap between hub and fork. For example 110mm hub and 110.8mm fork spacing. Measure this gap with a thickness gauge (feeler).* 0.8mm in my case. Then you can build a washer shim of 0.8mm thickness and install it...

Procedure to measure stiction (static friction, copied from motor bikes).*
* Remove most of the air... approx 60% of the air*
* Attach some weight to the 2 extremities of the bar. I used 2*10kg in my case, it was two set of snow chains for car, which was practical (in a fabric case with handles which I attached to the bar). The idea is to have a weight on your bar that can compress the fork to approx 50% travel. A motorbike is heavy so they don't have this problem but a MTB is too light to sag the fork. Adjust air pressure to have approx 50% of travel.
* Compress the fork totally, until stop, then release it. It will travel upward and stop. Lower the sag o ring to mark this position.
* Totally extend the fork (lift the bike) then release it (wheel must be on contact to ground when you release, not higher). fork will travel downward... in an ideal world (no stiction) it will stop exactly at the same place... it is not the case because of stiction. You can repeat the measurement 3 times and have an average.

In my case it was 25mm of stiction before shim installation And 21mm after. So fine tuning the shim helped a little bit, but still my fork is not very fine, 21mm is huge


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## spo0n (Nov 7, 2020)

nicolasswid said:


> OK, just some help to fine tune hub width.
> 
> Remove air of the fork.
> Turn your bike upside down. Loosen the axle. Normally there should be a gap between hub and fork. For example 110mm hub and 110.8mm fork spacing. Measure this gap with a thickness gauge (feeler).* 0.8mm in my case. Then you can build a washer shim of 0.8mm thickness and install it...
> ...


I wish i could test this but coil fork


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## nicolasswid (Apr 15, 2014)

If it's a coil fork you can do it, but with more weight (2x15kg?) maybe a little hard to do. Well coil fork should perform much better in the stiction area.


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## silvermax (Feb 11, 2020)

Thought i'd chime in with my '16 Reba that's been through its first season of use. The fork's been binding from new but i thought it would ease up with time. Didn't happen tho!

I did the bushings test back when i first got it and found out that it starts binding only when the wheel is clamped. It can be in the dropouts but as long as its not clamped = no friction/binding. Furthermore the harder i clamp it the more the friction. So i assume im having the same issue as nicolass which seems to be easier to fix. Luckily, im running Shimano cup and cone hubs so ill just stick the washer between the 2 locknuts that fix one of the cones as that increases the hub spacing.
As far as figuring out the thickness of the washer, im planning on taking out the seals on the next lowers service so i can feel everything by hand and then use the hub by adjusting the locknuts (causing axle play) untill i find a happy spot. Then calculate the before & after hub spacing.

Come to think of it, when i first found out about this binding i tried sticking a washer made out of a beer can between one hub endcap and dropout. The washer was 0.15mm thick but the binding didnt ease up and adding a second one made it worse so i assume that i need to go thinner than that :skep:. Wish i had a bigger spacing mismatch haha. So
considering how tight the stanchion/bushing/hub interface tolerances need to be i honestly cant imagine forks with zero bushings bind from factory unless they loosen up the bushings diameter a bit.


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## digev (Mar 7, 2019)

Another tight 36!


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## silvermax (Feb 11, 2020)

Seems like 36 Factory? Ugh. I’m pretty sure this is what you would call low quality control. What is Fox even thinking?


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## JB450 (Mar 31, 2019)

For those interested in making their own burnishing tool, with interchangeable heads. Another option is this.

I have used a threaded hole with a grub screw to stop the head from unscrewing, and also so I can interchange the heads.

Still have some machining to do on the head 









Sent from my INE-LX2 using Tapatalk


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## digev (Mar 7, 2019)

JB450 said:


> For those interested in making their own burnishing tool, with interchangeable heads. Another option is this.
> 
> I have used a threaded hole with a grub screw to stop the head from unscrewing, and also so I can interchange the heads.
> 
> Still have some machining to do on the head


Nice Job


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## petercarm (Nov 5, 2007)

Dougal said:


> They are all softer torsionally than conventional. How soft depends very heavily on the axle size and design.


One way to get a torsionally stiff upside down fork using elements from contemporary right side up architectures.









But you end up with the same "how do you take the wheel off" dilemma and nobody will buy into the asymmetry despite the spring and damper forces being asymmetric in our symmetric-looking forks


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## CCS86 (Jan 6, 2020)

petercarm said:


> One way to get a torsionally stiff upside down fork using elements from contemporary right side up architectures.
> 
> View attachment 1379629
> 
> ...


That looks less torsionally stiff to me. Less laterally stiff. Maybe more longitudinally stiff.

Plus, now all axial fork loads create an additional bending moment on the fork legs.

Sent from my Pixel 4 using Tapatalk


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## petercarm (Nov 5, 2007)

CCS86 said:


> That looks less torsionally stiff to me. Less laterally stiff. Maybe more longitudinally stiff.
> 
> Plus, now all axial fork loads create an additional bending moment on the fork legs.
> 
> Sent from my Pixel 4 using Tapatalk


I'm not going to go in depth as it is just a rendering and there is no math behind it. The upper tubes are conjoined so you have the effect of a conventional fork arch (only more so) and you have avoided all alignment issues.

Axial loads on conventional forks are inducing bending moments because of the spring on one side and damper in the other.

The rendering is a lefty. It doesn't attempt to house both spring and damper in the same leg and the rotation resistance is just like a conventional fork (twin stanchion) rather than square shaft and roller bearings. That's all. I did it about 6 years ago as a concept that didn't go anywhere (perhaps with reason).

No particular reason the idea couldn't be mocked up in dual crown with pretty basic workshop skills.


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## karpiel (Aug 27, 2010)

What devices are being used to hold the fork whilst re-sizing the bushes ?


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## johnsogr (May 31, 2009)

I just wedged my foot and leg in between the lowers.


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## wschruba (Apr 13, 2012)

johnsogr said:


> I just wedged my foot and leg in between the lowers.
> 
> Sent from my iPhone using Tapatalk


Clamp the lowers with an axle. Bad habit to get into, especially if you are twisting the burnisher.


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## CCS86 (Jan 6, 2020)

I think it's much safer to use rubber soft jaws in a vise to grab the fork leg you are working on and not use the other fork leg for restraint at all. The risk of damaging the brace isn't worth it to me.

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## digev (Mar 7, 2019)

karpiel said:


> What devices are being used to hold the fork whilst re-sizing the bushes ?


You step on the axle!










Source: https://m.pinkbike.com/photo/14377081/


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## johnsogr (May 31, 2009)

Interesting, I had the axle in, figured the forces I was creating with the burnishing tool wasn’t even close to what the fork was facing on the trail, but point taken


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## CCS86 (Jan 6, 2020)

johnsogr said:


> Interesting, I had the axle in, figured the forces I was creating with the burnishing tool wasn't even close to what the fork was facing on the trail, but point taken
> 
> Sent from my iPad using Tapatalk


The forces aren't even close because of how you're loading it and the fact that it's not in a complete assembly when you're burnishing.

You could huck 10ft to flat on an assembled fork and not hurt it. Or you could take the lowers in your bare hands, pull them apart and break the brace.

Sent from my Pixel 4 using Tapatalk


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## pedalinbob (Jan 12, 2004)

I finally completely disassembled my fork to isolate the friction between stanchion and bushing.
The drive side is tighter than the left, but not as severe as I expected.

Given this finding, I was wondering if something other than the bushings could cause the notchy feel (where my fork settles at sag and requires a big jump in force to resume movement, like it is binding).
For a recap: It is really noticeable: I can ride along, hitting maybe 1/2" bumps, and the fork won't budge until I hit a larger bump or exceed some threshold, where it "unbinds."
It is easily duplicated by pressing on the bars at a constant pressure and it will simply stop about an inch into travel.
I'm running low speed compression damping wide open (though may use 4 clicks at times) and have a pretty light high speed damping tune.

Anyway, I noticed that the rebound damper rod has a surprising amount of friction where it passes through the threaded cap.
I assume this is from the seal, which probably has to be pretty tight to keep the damper fluid in.

Is it possible that something other than the bushings could cause the binding?
I kinda doubt it, but figured I would ask anyway.

If the answer is no, then I better order the burnishing tool asap!

Bob


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## arc (Sep 9, 2004)

My 2020 F36 grip2 has a piston rod with varying diameters where the negative piston rides. First 40mm are ok, then tightens up until loosening up for the last 20mm. If the fork gets deep into travel it's really slow to rebound through the tight section. Its getting better over time. The fork feels pretty good for the first couple rides after a lowers service and then gets sticky again. 

The lower damper seal feels sticky as well, stickier than my old Van36 that came with a bent damper rod. The bushings don't seem overly tight for a fairly new fork but its going to take forever to bed them in with this amount of stiction.


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## digev (Mar 7, 2019)

BEFORE
https://streamable.com/ho66d4

AFTER
https://streamable.com/t5di9b

Credits: @creationcycles


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## wschruba (Apr 13, 2012)

arc said:


> My 2020 F36 grip2 has a piston rod with varying diameters where the negative piston rides. First 40mm are ok, then tightens up until loosening up for the last 20mm. If the fork gets deep into travel it's really slow to rebound through the tight section. Its getting better over time. The fork feels pretty good for the first couple rides after a lowers service and then gets sticky again.
> 
> The lower damper seal feels sticky as well, stickier than my old Van36 that came with a bent damper rod. The bushings don't seem overly tight for a fairly new fork but its going to take forever to bed them in with this amount of stiction.


I mean, this kinda sounds like a warranty issue. Did you call fox?


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## digev (Mar 7, 2019)

pedalinbob said:


> I finally completely disassembled my fork to isolate the friction between stanchion and bushing.
> The drive side is tighter than the left, but not as severe as I expected.
> 
> Given this finding, I was wondering if something other than the bushings could cause the notchy feel (where my fork settles at sag and requires a big jump in force to resume movement, like it is binding).
> ...


If one side is tighter than the other it may cause the fork to bind because one stanchion will slide slightly further down than the other and biding (a lock) will occur! therefore a massive amount of friction will happen and you'll need more force to «unbind» it and make it parallel/straight again ... before it can slide effortlessly again! In short, resizing your bushings should sort this out


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## pedalinbob (Jan 12, 2004)

Your are brilliant, sir!

I'm no engineer, but as a fairly skilled ex-wrench, that makes sense. I'm usually pretty good at sorting this sort of thing out, but I wasn't confident that I was fully isolating the issue, and the still-noticeable but much less severe friction threw me.

In theory, having both sides equally tight could result in smoother action overall because it may not go into a binding condition.

I think the way my fork moves smoothly for the first ~25mm or so, but becomes much tighter requiring a big jump in force, but returns to smooth movment is an in-your-face clue that it is binding.
I really don't think it is a normal air spring progressiveness.

I did bolt the wheel backing to see if it induces more friction, and there was no change.

I also thought about reassembling everything, placing the fork on a scale and slowly applying pressure to the crown and noting the jump in pressure required. 
I already know what is happening, but it would be cool to see it measured.
But, I'll just order the tool and get on with it.

I also think that each part of the system adds some friction, so when it is all together, the issue is magnified.

I'm probably just a victim of manufacturing variance, because I doubt that my barely 160lb butt is enough to stress the fork unusually.

Bob


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## digev (Mar 7, 2019)

pedalinbob said:


> Your are brilliant, sir!
> 
> I'm no engineer, but as a fairly skilled ex-wrench, that makes sense. I'm usually pretty good at sorting this sort of thing out, but I wasn't confident that I was fully isolating the issue, and the still-noticeable but much less severe friction threw me.
> 
> ...




Keep us posted


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## arc (Sep 9, 2004)

wschruba said:


> I mean, this kinda sounds like a warranty issue. Did you call fox?


I'm in Canada and we cannot deal with Fox directly. I have to deal with the Canadian Fox repair depots and don't get to pick which one. I have hopes for the new one on the eastern half of Canada being better than the old one. But I fully expect the fork to be gone for a month and then be told there is nothing wrong with it if I do send it in.


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## wschruba (Apr 13, 2012)

arc said:


> I'm in Canada and we cannot deal with Fox directly. I have to deal with the Canadian Fox repair depots and don't get to pick which one. I have hopes for the new one on the eastern half of Canada being better than the old one. But I fully expect the fork to be gone for a month and then be told there is nothing wrong with it if I do send it in.


This may as well be true, but you can save yourself a ton of grief by taking micrometer (not caliper) measurements of the shaft, and taking photo proof of it. While I'm aware that you generally can't squeeze parts out of the service department directly (even in the USA), you can start the groundwork as far as your expectations by calling. Get an RA/get the ball rolling on what you want them to look at. If you have a shop you use locally, they typically have more pull as far as warrantied/heavily discounted parts.


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## SqueakyWheel73 (Sep 21, 2018)

digev said:


> No probs I'm lubing the tool + bushings while doing it! Then I clean both after each pass.


So I'm seriously considering ordering the tool from Oliver so that I can resize my bushings. I've seen people recommending using the supergliss for lubing the bushings, but I haven't been able to find any online here in the US. What else can be used for this purpose?


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## The_Bob (Jan 16, 2018)

Whatever you use for your lower leg lube should be fine. I used Fox Gold when working on my Pike with good results


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## digev (Mar 7, 2019)

The_Bob said:


> Whatever you use for your lower leg lube should be fine. I used Fox Gold when working on my Pike with good results


Absolutely 

Now if you really want some Motorex Supergliss you can order some from Dougal @ shockcraft.co.nz, he's shipping small quantities worldwide! Some buddies also tried the EXT performance lube with great results (this thing sticks and it's very slippery as well) and they have distributors in the US

Source: http://www.extremeshox.com/wp-content/uploads/2018/07/HDT68SYNTH.pdf

Tip: If you have a RS, you can use 15cc of oil in each leg instead of the recommended 10cc to lubricate even more (I do that since last season with no «obvious» downside)


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## nicolasswid (Apr 15, 2014)

So I decided to disassemble the fork (SID 2018) and check again everything , after bushing resize the fork was better, but not so good... same kind of problems as bob.

I decided to measure and track every stiction force. All the measures are done in clean, lubed condition, with good quality lubricant (supergliss and RS dynamic seal grease).

On the entire fork (deflatted)... cannot measure because the value is too high for my kitchen scale... probably 4kg! that it huge. Dougal recommends a total of 2kg.

Without damper (stiction of bushings*+ wiperseals*+ air spring): still too high to be measured.
Without air spring: (stiction of bushing*+ wiper seals): 900 g* * in a "free state" (without wheel axle). The 2 wiper seals should have approx 800g of stiction (the bushings are resized, so the stanchions are falling in the lowers by their own weight, bushing stiction is almost zero WHEN NOT STRESSED (without forces).* * bushing*+ wiper seals stiction is* 2700 g in a stressed state (wheel axle tightened at the maximum, without hub... the goal is kind of simulate the loads that occur on the fork during riding.

I tried to do some "cross hatch*wet sanding of the stanchions" (as done by motocross) on a small portion of the stanchions... but measure was slightly worst*or identical.

Stiction of air spring alone: 2200-2900g* IT is huge! a lot of stiction in the air spring. Sticion of main piston (positive spring):500-1600 g (results vary a lot)
Sticion of negative piston small O-ring (inner): 200-500 g* 
Sticion of negative piston big O-ring (outer): 1600 g**

So the bushings is now OK after resizing, problem is now on the Air spring. My O rings have been changed a few months ago... but they are perfectly broke in (25 hours riding maybe). They are supposed to be the new 2020 O-rings (compatible but another material to be compatible with new Rockshox dynamic seal grease). 
So I changed the big O-rings with the old one I removed during the maintenance (approx 100 hours of riding, looks perfect). Stiction dropped from 1600g to 400-900 g* per o-ring.I realized that you did not need so much sealing from the main "positive" piston. The reason is that, if it leaks, it will leak inside the negative chamber, and then the negative chamber will send it inside the positive chamber through the dimple when the fork is extended... so I filed (grinded) a little bit the inside diameter of plastic throat of the piston... like 0.2mm was removed at diameter. Until the stiction was better... around 400g for this seal.
After this, the complete air piston (positive*+ negative) lubed with dynamic seal grease + supergliss have 500-800g! approx 2kg gained!
Stiction of the complete fork is approx 2kg right now.

After a ride, it is a totally different fork, now it really travel and follow the terrain... still not as good as my lefty hybrid or my old coil marzocchi, but acceptable for a fork of this price.

So as Dougal say it seems friction can come from any of the parts: bushing, seals, air spring, damper...
If you have some problems, my 2 cents would be to measure everything before investing .


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## croakies (Mar 4, 2011)

nicolasswid said:


> So I decided to disassemble the fork (SID 2018) and check again everything , after bushing resize the fork was better, but not so good... same kind of problems as bob.
> 
> I decided to measure and track every stiction force. All the measures are done in clean, lubed condition, with good quality lubricant (supergliss and RS dynamic seal grease).
> 
> ...


Cool exercise man  good to hear you got positive results out of it.

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## SqueakyWheel73 (Sep 21, 2018)

I disassembled my Fox 36 last night, removed the seals and damper and air shaft and experimented with how much binding there was. Initially, I was pleasantly surprised - the uppers slid through the upper set of pushing reasonably smoothly but definitely encountered some friction/binding when the lower bushing are engaged.

I then installed a wheel and torqued the through-axle to spec and tried again. It was *substantially* worse. I was really shocked by how much force it took to push the fork down the final 10-20 mm of its travel.

So what's the best way to go about solving this? I would like to get the tool to hone the bushings, but it seems like the issue with the axle width needs to be resolved first. My front hub is a DT Swiss 240. My assumption is that the hub is too narrow since I don't need to spread the fork legs to get the axle in. If this is correct, are there shims that can be purchased to help widen the axle length to minimize the binding that I am seeing?


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## gatag (May 21, 2015)

I've been thoroughly reading these suspension threads, very good information mainly from Dougal et al. I am waiting for my Lyrik Ultimate and want to get the most of it right off the bat. Thinking of ordering a tool from Oliver. 

The thing that has me baffled is: why do you guys think that the burnishing procedure is not done at the factory? I would reckon that doing so would add almost nothing in terms of cost and time into the production line and the benefits (from what I've been reading) are enormous. Brands could make a good forks into outstanding forks just by adding +/-15 minutes of extra labor.


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## digev (Mar 7, 2019)

nicolasswid said:


> So I decided to disassemble the fork (SID 2018) and check again everything , after bushing resize the fork was better, but not so good... same kind of problems as bob.
> 
> I decided to measure and track every stiction force. All the measures are done in clean, lubed condition, with good quality lubricant (supergliss and RS dynamic seal grease).
> 
> ...


Cool stuff man! I always wanted to «measure» each component to have a rough estimation of all this.

But now that I use a coil + open bath + resized bushings I can't be bothered because it's all I ever expected in terms of performance and tracking but it's still very interesting to read what you've done!

On that note (seals/ friction) I kept the Dual flow rebound from the Yari BUT after noticing a huge amount of friction between the rebound shaft and the seal head assembly during servicing I swapped it for an x-ring seal and it was better but still very sticky, then tried with a regular O-ring and it and made a huge difference ... with everything lubed and just cycling by hand (not the best way to measure but here you go) it was night and day different ... so much smoother in fact than I had to re-shim the rebound stack because it was too fast  (more info: https://forums.mtbr.com/shocks-suspension/super-yari-1069974.html#post14327017

So, yes ... disassembling and testing each component/assembly to try and find out if the friction can be reduced is definitely a good thing! Empty stanchions sliding inside empty lowers is just one of those tests 

Thanks for sharing your findings


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## digev (Mar 7, 2019)

SqueakyWheel73 said:


> I disassembled my Fox 36 last night, removed the seals and damper and air shaft and experimented with how much binding there was. Initially, I was pleasantly surprised - the uppers slid through the upper set of pushing reasonably smoothly but definitely encountered some friction/binding when the lower bushing are engaged.
> 
> I then installed a wheel and torqued the through-axle to spec and tried again. It was *substantially* worse. I was really shocked by how much force it took to push the fork down the final 10-20 mm of its travel.
> 
> So what's the best way to go about solving this? I would like to get the tool to hone the bushings, but it seems like the issue with the axle width needs to be resolved first. My front hub is a DT Swiss 240. My assumption is that the hub is too narrow since I don't need to spread the fork legs to get the axle in. If this is correct, are there shims that can be purchased to help widen the axle length to minimize the binding that I am seeing?


The thing is ... no matter what's causing the issue, out of shape bushings, tight bushings, slight stanchions tolerance variations (roundness, diameter), misalignment etc ... it will always create an «undesirable» contact point between the stanchion(s) and the bushing(s), so by creating more room between those 2 parts you're almost always guaranteed to improve the overall performance no matter the chassis issue(s). It's kind of a generic approach to solve all this in one go! But nothing's wrong about solving what is really causing the issue


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## digev (Mar 7, 2019)

gatag said:


> I've been thoroughly reading these suspension threads, very good information mainly from Dougal et al. I am waiting for my Lyrik Ultimate and want to get the most of it right off the bat. Thinking of ordering a tool from Oliver.
> 
> The thing that has me baffled is: why do you guys think that the burnishing procedure is not done at the factory? I would reckon that doing so would add almost nothing in terms of cost and time into the production line and the benefits (from what I've been reading) are enormous. Brands could make a good forks into outstanding forks just by adding +/-15 minutes of extra labor.


Good question!


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## JB450 (Mar 31, 2019)

gatag said:


> cost and time


Exactly this.

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## nicolasswid (Apr 15, 2014)

cost and time! The fact is most forks are supposed to be OK and do not need burnishing, on those forks, burnishing would be counter productive (too much play). So if you want to do it well, that's a lot of trials.
I think fork manufacturers used to sell with more play (clearance) before and too much peoples complained about play in fork. Now they sell 1500 dollars fork that does not travel and everyone is happy.

It is very hard and expensive to manufacture 200mm stanchions with less than 0.1mm of deviation


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## nicolasswid (Apr 15, 2014)

you can check the width of the hub. And of the fork. And correct it with shims/washers. PLease see my post above you can search "feeler gauge"


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## SqueakyWheel73 (Sep 21, 2018)

nicolasswid said:


> you can check the width of the hub. And of the fork. And correct it with shims/washers. PLease see my post above you can search "feeler gauge"


Thanks - I remembered reading that post but I haven't had time to go back and re-read everything. The feeler gauge is a good idea. Were you able to purchase the shims or did you actually make these yourself?


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## FactoryMatt (Apr 25, 2018)

gatag said:


> I've been thoroughly reading these suspension threads, very good information mainly from Dougal et al. I am waiting for my Lyrik Ultimate and want to get the most of it right off the bat. Thinking of ordering a tool from Oliver.
> 
> The thing that has me baffled is: why do you guys think that the burnishing procedure is not done at the factory? I would reckon that doing so would add almost nothing in terms of cost and time into the production line and the benefits (from what I've been reading) are enormous. Brands could make a good forks into outstanding forks just by adding +/-15 minutes of extra labor.


my lyrik was fine out of the box bushingwise. if you want to get the most out of it, send your damper cartridge to Dougal. Trust me.

re burnishing, probably tool costs, and a likely increase in warranty replacements for folks that wear their forks until they knock. my guess.


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## digev (Mar 7, 2019)

gatag said:


> I am waiting for my Lyrik Ultimate and want to get the most of it right off the bat. Thinking of ordering a tool from Oliver.


In the words of «Paul Thede»

Source: Race Tech's Motorcycle Suspension Bible (Chapter 4 - Friction)



> Friction ... BAD! As far as suspension components are concerned, the less friction you have on sliding surfaces, the better the suspension works





> II is my opinion that friction is the first area that should be addressed before any other suspension tuning or setup is done.





> Remember, reduce friction first, then go to springs, then damping


There you have it 

PS: This book is pure gold ... recommended by Jono @ thesuspensionlab a few months ago (can't thank him enough)


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## silvermax (Feb 11, 2020)

nicolasswid said:


> cost and time! The fact is most forks are supposed to be OK and do not need burnishing, on those forks, burnishing would be counter productive (too much play). So if you want to do it well, that's a lot of trials.
> I think fork manufacturers used to sell with more play (clearance) before and too much peoples complained about play in fork. Now they sell 1500 dollars fork that does not travel and everyone is happy.
> 
> It is very hard and expensive to manufacture 200mm stanchions with less than 0.1mm of deviation


Yeah. Its just not a process that can be automated. There are just too many variables. Stanchion misalignment and diameter tolerance, dropouts and hub spacing difference. You can't just take the reamer and size the bushings to a given diameter and call it a good job. A pair of stanchions need to be matched to a pair of lowers, then mounted to a hub then assess.

So i guess manufacturers pick the lesser evil of the two (obviously people dont like wrecked stanchions after 6 months)


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## Nick_M2R (Oct 18, 2008)

Took delivery of Olivers Bushing sizing tool. Finally got around to using it the other day, on 2 sets of Lyrik's. The first was a Lyrik Ive had on my Remedy for a year, the second was a brand new Lyrik Ultimate.

I must say, I wasn't sure how much of a difference I would notice. Don't get me wrong, was happy to order the bushing tool as Im a sucker for a well made custom tool! After using it however?

Holy $h!t am I a believer.

Lyrik 1:

Given this fork had been used for awhile, the lowers where able to fall into the lowers by their own weight, but with a high degree of resistance. 4 passes through each Upper and Lower bushing, and the difference was substantial. The lowers now glide smoothly into the fork, with no noticeable knocking.

Lyrik 2:

Brand new Lyrik Ultimate. Dang the bushings in this thing where TIGHT. Uppers would not go into the lowers on their own weight, needed to be pushed, with significant break away force to get it moving. This needed about 8 passes through each upper and lower bushing. Once done though, again the difference was incredible! Will be taking it out for its first ride this weekend and will report back

Pics below show the CSU and Lowers. First is before burnishing, and shows the uppers not going into the lowers. Second is after burnishing, and them gliding in smoothly under their own weight.

















Observations:

You will need some way of holding the lowers, as the force to rotate the burnishing head into the bushing can be significant, even with oil applied (I used Fox Gold). A pic above shows a fox tech using his foot on the axle, personally I feel this is a great way to potentially damage your lowers. I placed the lowers on my front wheel, stabilised the wheel against a wall and gripped it with my legs. Bit of a dance, but once you get the hang of it, gives FAR better stability to the lowers whilst your rotating the tool in. Its a work out! Get ready to get the arms pumping, especially if your bushings are tight.

Another thing I noticed. Olivers tool consists of the main shaft with a threaded rod going through it, that the handle and burnishing head tighten onto. When you rotate the tool clockwise down into the bushings, it tightens both the handle and burnishing head onto the shaft. Don't be tempted to start rotating it counter clockwise to help pull the tool back through the bushings, as if the bushings are very tight, there is a chance it could cause the burnishing head to loosen off the threaded rod. You'll hear and feel it, PAY ATTENTION! Immediately go clockwise to tighten, and keep doing so whilst pulling hard through the bushing. If the tool head loosens off and falls in the lowers, you're F$%ked. Buy a new set of lowers, will be easier than getting the tool head out due to the tolerances!

Final Word:

Im very happy with this tool! Well made, and does the job. Got a few of my riding buddies wanting to use it so its payed for itself already. For myself, I got both the 35.07 and 35.10 sized head. I only used the 35.07 and was more than happy with the results on that.


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## karpiel (Aug 27, 2010)

Excellent writeup, I also have a tool on order with Oliver, hope I have as much success.
You could rotate tool clockwise to remove ? Maybe ?


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## ghostbiker (Oct 24, 2018)

karpiel said:


> e
> You could rotate tool clockwise to remove ? Maybe ?


Absolutely yes and you should do it that way.


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## SqueakyWheel73 (Sep 21, 2018)

Nick_M2R said:


> Lyrik 1:
> 
> Given this fork had been used for awhile, the lowers where able to fall into the lowers by their own weight, but with a high degree of resistance. 4 passes through each Upper and Lower bushing, and the difference was substantial. The lowers now glide smoothly into the fork, with no noticeable knocking.


My Fox 36 is very similar to your Lyrik 1. I did an extra check with the axle installed, and the resistance became significantly higher - the lowers stopped about half an inch from the bottom. I described this to Oliver and he recommended shims on the axle rather than trying to take more material off the bushings. So he's making me a few axle shims to see if it helps.

I'll be really curious if you can notice any significant difference in this fork. It sounds like the difference for the second Lyrik could/should be more dramatic. Please post back after you've gotten some rides in on your forks.


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## mike156 (Jul 10, 2017)

ALWAYS turn the tool clockwise.

We aren't threading the bushings, there is no reason to turn it counter clockwise. The head unscrewing is a BIG reason to turn it clockwise though.


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## Nick_M2R (Oct 18, 2008)

karpiel said:


> You could rotate tool clockwise to remove ? Maybe ?


Correct, my observation was more as a share for anyone considering the tool, who might not be aware of what to look for and try to back it out via anti-clockwise rotation. I had intended to only remove it via clockwise rotation, but the second Lyriks bushings initially where so tight, even with the Fox Gold, it was very difficult to remove via clockwise rotation and pulling, so I gently went via anti-clockwise rotation to make backing it out easier, but was very careful whilst doing so. I had torqued the burnishing head to a high torque so it didn't come loose.

More a warning for anyone considering the tool


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## Nick_M2R (Oct 18, 2008)

mike156 said:


> ALWAYS turn the tool clockwise.
> 
> We aren't threading the bushings, there is no reason to turn it counter clockwise. The head unscrewing is a BIG reason to turn it clockwise though.


Correct, more a warning for anyone considering getting the tool who might not be aware of it, as its not mentioned. To many it makes sense, but to others who might not be as familiar burnishing tools, especially when it requires a lot of force to rotate the tool


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## digev (Mar 7, 2019)

Nick_M2R said:


> Correct, more a warning for anyone considering getting the tool who might not be aware of it, as its not mentioned. To many it makes sense, but to others who might not be as familiar burnishing tools, especially when it requires a lot of force to rotate the tool


I did mention it at some point but it's worth repeating 

Thanks for sharing your feedback, that's great! Now hit the trails to feel the difference


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## digev (Mar 7, 2019)

SqueakyWheel73 said:


> My Fox 36 is very similar to your Lyrik 1. I did an extra check with the axle installed, and the resistance became significantly higher - the lowers stopped about half an inch from the bottom. I described this to Oliver and he recommended shims on the axle rather than trying to take more material off the bushings. So he's making me a few axle shims to see if it helps.


Out of curiosity, did you measure your hub width and spacing between the lowers? Just to find out where the mismatch comes from


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## digev (Mar 7, 2019)

karpiel said:


> Excellent writeup, I also have a tool on order with Oliver, hope I have as much success.
> You could rotate tool clockwise to remove ? Maybe ?


HeyHey fellow Yeti rider 

It's a very simple process, you'll see ... but we could ask Oliver to add a feature so it locks the die to prevent any unscrewing (Like CCS86 did), that's the beauty of hand made tools and a single point of contact listening to our needs


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## JB450 (Mar 31, 2019)

Finished tool.

Grub screw to stop any chance of unthreading. And to allow multiple sized heads.









Sent from my INE-LX2 using Tapatalk


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## digev (Mar 7, 2019)

JB450 said:


> Finished tool.
> 
> Grub screw to stop any chance of unthreading. And to allow multiple sized heads.
> 
> ...


Woow! Looks gigantic or is it just the perspective? Good job, very cool to see homemade tools as well! (Oliver's tool or any other allow for multiples heads/dies as well)


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## JB450 (Mar 31, 2019)

digev said:


> Woow! Looks gigantic or is it just the perspective? Good job, very cool to see homemade tools as well! (Oliver's tool or any other allow for multiples heads/dies as well)


Mostly perspective I would say, but it is definitely most probably longer than required 

I couldn't be bothered cutting the shaft down (it's a piece of stainless steel pipe). Handle is a piece of 1/2 inch stainless tubing and the head is a piece of stainless round bar. All parts were liberated from the scrap bin at my work.

Sent from my INE-LX2 using Tapatalk


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## GH28 (Jun 16, 2014)

If tool drawer space were not a concern, I wonder if it would be way cheaper to make a handful of long bowling-pin looking tools that only had a cross-hole drilled for a handle or a large screwdriver. No threading at all. A bunch of metal with one precision surface each and the rest gets rough cut. And no retention risk of something getting dropped inside the lowers.


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## SqueakyWheel73 (Sep 21, 2018)

digev said:


> Out of curiosity, did you measure your hub width and spacing between the lowers? Just to find out where the mismatch comes from


I didn't actually measure it, but here was my observation:

1) With no axle/hub in the lowers, the uppers dropped into the lowers under their own weight. Definitely a little friction, but still a 'thunk' when the uppers bottomed out.

2) With the hub between the lowers and the axle threaded but no tension applied, there was no difference from #1.

3) When I torqued the axle to spec, the friction/binding definitely increased and the lowers stopped falling on their own about half an inch from the bottom. It took noticeable force to push them all the way down.

The friction/binding increased in the last quarter to half turn of the axle. So the lowers are definitely getting pulled in on the hub, causing the binding. We aren't talking much, but I don't have feeler gauges around to try to measure it and Oliver didn't seem to think it was necessary.


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## wschruba (Apr 13, 2012)

GH28 said:


> If tool drawer space were not a concern, I wonder if it would be way cheaper to make a handful of long bowling-pin looking tools that only had a cross-hole drilled for a handle or a large screwdriver. No threading at all. A bunch of metal with one precision surface each and the rest gets rough cut. And no retention risk of something getting dropped inside the lowers.


It would be much more expensive, too. The stock would, at the minimum, need to be slightly larger than the burnishing surface, and would need quite a bit of machining. Versus the two-piece design: pick a standard piece of stock, and attach a head of 20-30 millimeters in length to it.

A pair of pins, like on large milling cutters/taps would suffice. The head of the tool is then retained by the screw, and not being driven by it.

See: the locating pins, just visible, at the base of the taps









Best practice would still be turning the tool only in the direction of the threading, though. Cutting/reaming tools work best when used consistently, and it isn't just in this case. You could unscrew the handle from a rat-tail file if you turned it the wrong way during draw-filing...but that wouldn't be the fault of the handle.


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## digev (Mar 7, 2019)

SqueakyWheel73 said:


> When I torqued the axle to spec, the friction/binding definitely increased and the lowers stopped falling on their own about half an inch from the bottom. It took noticeable force to push them all the way down.
> 
> The friction/binding increased in the last quarter to half turn of the axle. So the lowers are definitely getting pulled in on the hub, causing the binding. We aren't talking much, but I don't have feeler gauges around to try to measure it and Oliver didn't seem to think it was necessary.


Fair enough


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## The_Bob (Jan 16, 2018)

Got to 30 hours on my 34 Factory and decided to do the lowers and bushings. The two upper bushings were a bit tight, the lower ones were ok. The foam rings were quite dry. Lubed everything, new fluids and buttoned it back up. It is so smooth now it is ridiculous. I had to add 2PSI to my pressure to get 20% sag, but it feels amazing. Thanks again Digev for the thread and the info for the tool


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## digev (Mar 7, 2019)

The_Bob said:


> Got to 30 hours on my 34 Factory and decided to do the lowers and bushings. The two upper bushings were a bit tight, the lower ones were ok. The foam rings were quite dry. Lubed everything, new fluids and buttoned it back up. It is so smooth now it is ridiculous. I had to add 2PSI to my pressure to get 20% sag, but it feels amazing. Thanks again Digev for the thread and the info for the tool


You're Welcome! Enjoy the buttery smooth fork and hopefully it will stay like that for a lot longer now ... The different «feel» (like you described) is exactly what you notice first! Thanks for the feedback, always appreciated


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## JB450 (Mar 31, 2019)

Lowers service today and bushing burnish.

Soo much stiction before burnishing.

Homemade tool works a treat.

For reference I made the head to 35.08 for my revelations.


__
http://instagr.am/p/CI78JmZhWxR/

Sent from my INE-LX2 using Tapatalk


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## digev (Mar 7, 2019)

JB450 said:


> Lowers service today and bushing burnish.
> 
> Soo much stiction before burnishing.
> 
> ...


That tool is Huuuge 

Happy for you it worked out great! Thanks for sharing the pics and the diameter


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## JB450 (Mar 31, 2019)

digev said:


> That tool is Huuuge
> 
> Happy for you it worked out great! Thanks for sharing the pics and the diameter


No worries 

Hahaha, yeah it is pretty bloody long.

Worked well with the lowers bolted to the wheel with me sitting on the wheel though.

Definitely recommend doing it that way as apposed to standing on the axle. Was much easier and no chance of damaging the lowers.

Sent from my INE-LX2 using Tapatalk


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## digev (Mar 7, 2019)

JB450 said:


> No worries
> 
> Hahaha, yeah it is pretty bloody long.
> 
> ...


Time to test ride it now, here comes the fun part


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## JB450 (Mar 31, 2019)

digev said:


> Time to test ride it now, here comes the fun part


Might have a bounce in the street tomorrow.

But Sunday is proper ride day 

Sent from my INE-LX2 using Tapatalk


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## The_Bob (Jan 16, 2018)

Rode today with the serviced and burnished 34. I have *ALL* the small bump compliance. Fork is amazingly supple.


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## digev (Mar 7, 2019)

The_Bob said:


> Rode today with the serviced at burnished 34. I have *ALL* the small bump compliance. Fork is amazingly supple.


Hahaha ... now you know what we were talking about


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## FactoryMatt (Apr 25, 2018)

did a Supercaliber bushing with Oliver's burnishing tool. it went from so tight the stanchion would hardly move without twisting it, to perfect. absolutely perfect. not too loose, not too tight. only took one pass, though it was a VERY difficult pass. OD of the tool was ~36.1mm using Verniers. Really stoked.


http://imgur.com/zbBl4OU


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## digev (Mar 7, 2019)

FactoryMatt said:


> did a Supercaliber bushing with Oliver's burnishing tool. it went from so tight the stanchion would hardly move without twisting it, to perfect. absolutely perfect. not too loose, not too tight. only took one pass, though it was a VERY difficult pass. OD of the tool was ~36.1mm using Verniers. Really stoked.


Whoop Whoop  Nice one! I saw a post few months ago from @diazsuspensiondesign where he was showing the amount of stiction coming from the 36mm bushing inside the supercaliber ...



> When your rear shock is hiding in a [ it's actually a 36 stanchion, not a 40, FYI ] you get a shock overhaul, custom tune, and mini fork overhaul all in one. As you can tell from the video, the bushings inside the frame of this Trek SuperCaliber [we found the same issue on another frame as well] are super-uber-dooper tight. In this case it's more likely a manufacturing issue in the carbon fiber chassis of the iso strut because the bushings don't sit perfectly round inside the frame. In any case, we had to go way outside our normal bushing fitment routine to re-super this super caliber. In the end, this customer had a far more supple ride not only from the bushing adjustments but also from the custom tuned baby shock. Which, believe it or not, make a massive difference when you only have 60mm of rear wheel travel.


Source: https://m.facebook.com/diazsuspensi...-stanchion-not-a-40-fyi-you/3643325625719523/ (with video)

Where the Fork was the obvious place to start in reality every part with a bushing can be adjusted/improved if necessary (like you just did)

Take the integrated dropper post from BMC for example (sliding up and down the frame on 2 bushings) , the RAD ... well they sell something they call the «calibration tool» when you swap the bushings to re-shape them and make sure they are perfectly round, because they know it makes a difference 

Source: https://www.bmc-switzerland.com/media/downloads/download/rad_bushing_remplacement_2020_EN.pdf


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## JB450 (Mar 31, 2019)

After having a bounce around the street today to re-adjust settings (after the burnishing) I have ended up with a little bit more sag at the same pressures, but have had to dial in some actual rebound for once 

The bushes were actually slowing down my rebound for me 









Sent from my INE-LX2 using Tapatalk


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## digev (Mar 7, 2019)

2 months ago while reviewing/comparing the 38 and ZEB the guys at BikeRadar used a «spring dyno» while visiting Mojo! (They did that to measure the total spring force against travel for both forks)










Now this is where it becomes interesting (from a friction point of view), they published the following graph showing the results for the first 120mm of travel



> The dotted lines show the force measured when the fork was allowed to rebound - the difference between the dotted and solid lines is due to friction












Both forks have roughly:

10kgf of friction at 20mm
30kgf of friction at 120mm

Do I read that right?

Source: RockShox Zeb vs Fox 38 | Hard-hitting enduro forks go head-to-head


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## mike156 (Jul 10, 2017)

I would assume some of that is rebound damping force. Probably like the 10kgf at 20mm is mostly friction from the bushings and wiper seals. The extra 20kgf is the air piston seals and then rebound damping.


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## digev (Mar 7, 2019)

Can't help it 










Merry Christmas everyone 

Source: @mtbmaker


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## spo0n (Nov 7, 2020)

Who is burnishing Mezzers?


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## CCS86 (Jan 6, 2020)

spo0n said:


> Who is burnishing Mezzers?


For the vast majority, no need at all.

The bushing fit seems to range from spot on, to a touch loose.

Sent from my Pixel 4 using Tapatalk


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## spo0n (Nov 7, 2020)

CCS86 said:


> For the vast majority, no need at all.
> 
> The bushing fit seems to range from spot on, to a touch loose.
> 
> Sent from my Pixel 4 using Tapatalk


awesome to hear, mine came yesterday 😃


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## CCS86 (Jan 6, 2020)

spo0n said:


> awesome to hear, mine came yesterday


Definitely worth a quick tear down to make sure the IRT and main air pistons are well greased. I love my Mezzer.

Sent from my Pixel 4 using Tapatalk


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## spo0n (Nov 7, 2020)

CCS86 said:


> Definitely worth a quick tear down to make sure the IRT and main air pistons are well greased. I love my Mezzer.
> 
> Sent from my Pixel 4 using Tapatalk


Already done haha, plenty of slickoleum on the irt piston and main piston.


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## mike156 (Jul 10, 2017)

One leg on my Mezzer was tight enough to keep the uppers from dropping in under there own weight. It would actually stop an already moving stanchion in the same place every time. After Going through with the burnishing till 3-4 times though, it's smooth.

The other leg was considerably easier to burnish and only needed one pass.


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## digev (Mar 7, 2019)

mike156 said:


> One leg on my Mezzer was tight enough to keep the uppers from dropping in under there own weight. It would actually stop an already moving stanchion in the same place every time. After Going through with the burnishing till 3-4 times though, it's smooth.
> 
> The other leg was considerably easier to burnish and only needed one pass.


Thanks for sharing your feedback


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## 294037 (Jun 30, 2006)

digev said:


> 2 months ago while reviewing/comparing the 38 and ZEB the guys at BikeRadar used a «spring dyno» while visiting Mojo! (They did that to measure the total spring force against travel for both forks)
> 
> 
> 
> ...


That's not just friction, that's (also some undetermined percentage of) hysteresis due to the adiabatic process of compressing an air spring. Even a frictionless air spring will look like that


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## digev (Mar 7, 2019)

JohnnyC7 said:


> That's not just friction, that's mostly hysteresis due to the adiabatic process of compressing an air spring. Even a frictionless air spring will look like that


I'm not sure to fully understand what you mean but let's say it's really what happens, then why would they test it like that and make a difference between the dotted and solid lines? And of course write the difference between the 2 = friction?

To be honest I found those numbers rather high (ex: 10kgf of friction for the first 20mm of travel) and that's why I asked if it was the right way to read/understand this graph ... so your explanation of «something else» happening makes sense

Now I understand the confusion about «someone» saying you can get up to 50kgf of friction when asked to talk about the ERA vs other forks ...if they used that method!

What would be the «right» way to do it in your opinion please? To show people the difference between fork X and Y or before and after burnishing for example?

Thanks for you expertise


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## CCS86 (Jan 6, 2020)

The basic theme is that you generate heat when compressing an air spring and that increase in air temp, inside the air spring, is contributing to the spring force. This heat is dissipating to the environment during the test, reducing the spring force. If you compressed the fork to a certain position and held it there, you should see a drop in spring force as temps equalize.

Without crunching the numbers I don't know how large an effect this is relative to the air spring forces generated. My gut says that it isn't the lion's share of that delta though.

I think that in this type of test you see the friction effect doubled up, because friction is resisting the compression, adding to the spring force generated. Then, during the rebound stroke, friction is acting in the opposite direction, reducing the spring force generated. So, for every 1 kg of frictional force, I believe you will see a 2 kg separation between those traces.

Sent from my Pixel 4 using Tapatalk


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## mike156 (Jul 10, 2017)

What. No. That's not right. I'd have to run the numbers but there is no way you are losing that much to entropy.

Edit: should have refreshed the page as this response was to JohnnyC7.

CCS86 is likely on the right path. The compression ratio is low on a fork so the heat energy will be low as well. That heat will be returned to the air on expansion with a slight lose to entropy.


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## digev (Mar 7, 2019)

Thank you for the explanation guys, now I understand


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## Dougal (Jan 23, 2004)

Those plots make no sense at all. TBH the same theme applies to most of the claims we saw regarding a recent fork release from the same source.

Air spring hysteresis depends on compression/extension speed. When using a bottle jack rig (as the pics show) the compression would be very slow. But how fast was the extension?


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## 294037 (Jun 30, 2006)

CCS86 said:


> I think that in this type of test you see the friction effect doubled up, because friction is resisting the compression, adding to the spring force generated. Then, during the rebound stroke, friction is acting in the opposite direction, reducing the spring force generated. So, for every 1 kg of frictional force, I believe you will see a 2 kg separation between those traces.


Yes that is true, the friction force is acting in both directions her which widens the gap. 10kg is a very realistic number (5kg either way) but 30kg would be pretty concerning, especially considering the ERA is supposed to have significantly reduced friction

Thats the problem with sharing a graph like this, the friction alone is larger than the difference in rate throughout the stroke! Which makes it pretty meaningless since there is considerable overlap between where the "true" values lie. I would to see some notes attached with a friction value as well as how the test was performed


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## link1896 (Jul 13, 2007)

Tool for spreading lowers to spot on 100/110

An old TA with a sleeve turned up for a perfect fit, grub screw to lock to the shaft.

Turn the assembly and legs spread open.


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## link1896 (Jul 13, 2007)

Measuring fox 36 stanchions with a calibrated external micrometer, calibrated with a standard at 25mm and 50mm, I’ve got 2019 36 performances on the bench. Matte black stanchions.

One measures 35.92, other 35.95 mm. Consistent all along, round. Forks have 200 hours on them. 


From digev’s first post, bushing clearance window is 0.0381 to 0.286mm.

Do we want to land at 0.133mm? Plasticity gives us a 0.07ish result from a 0.1mm head over a few passes? 

I’m seeing many burnishing heads in my future. 

Has anyone used an accurate internal micrometer to measure results?


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## digev (Mar 7, 2019)

link1896 said:


> Measuring fox 36 stanchions with a calibrated external micrometer, calibrated with a standard at 25mm and 50mm, I've got 2019 36 performances on the bench. Matte black stanchions.
> 
> One measures 35.92, other 35.95 mm. Consistent all along, round. Forks have 200 hours on them.
> 
> ...


People seem to be really happy about the +0.07mm head/die! After feeding the tool, the material will spring back a little and in reality you've probably stretched the bushings by +0.02mm

It may sound a bit conservative but in reality it does the trick! Like Dougal mentioned on this thread the «ideal» match would be as much wiggle room as you can without impacting what the bushings should be doing in the first place ... guiding the stanchions without any play.

Without knowing the exact stanchions/bushings OD/ID diameter and roundness you can't find that «perfect» match but the generic approach of increasing the bushings ID a little and reshaping (probably as important) them in the process seems to be the simplest and best approach so far ... AND it works on the trails in real life, probably the best way to measure the results 










Source: Sizing of a NORGLIDE PTFE Bushing | Saint-Gobain

Happy New Year Guys and thanks to all of you who contributed to this thread so far, let's slide smoothly into 2021 

It's now time for the last ride of the year 

Take care and enjoy!!!


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## JB450 (Mar 31, 2019)

link1896 said:


> Measuring fox 36 stanchions with a calibrated external micrometer, calibrated with a standard at 25mm and 50mm, I've got 2019 36 performances on the bench. Matte black stanchions.
> 
> One measures 35.92, other 35.95 mm. Consistent all along, round. Forks have 200 hours on them.
> 
> ...


FWIW the final dimension of the burnishing head I made for my 35mm revs was 35.08.

I didn't think my forks were too bad on the trail, but after 3 passes through each bush (4 through one of them due to a small flat side of a lwr Bush from installation) the difference was huge.

I could've probably in hindsight done an extra pass or two through each bush, but I was conscious of not ending up with bushing play.

Each pass was easier and easier to complete.


digev said:


> People seem to be really happy about the +0.07mm head/die! After feeding the tool, the material will spring back a little and in reality you've probably stretched the bushings by +0.05mm
> 
> It may sound a bit conservative but in reality it does the trick! Like Dougal mentioned on this thread the «ideal» match would be as much wiggle room as you can without impacting what the bushings should be doing in the first place ... guiding the stanchions without any play.
> 
> ...


Happy New year.

Sent from my INE-LX2 using Tapatalk


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## Rey112 (Jan 1, 2021)

.


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## Dougal (Jan 23, 2004)

Burnishing isn't all about sizing bushings. It's largely about shaping bushings.
Many go in slightly egg shaped which means they are contacting the stanchions at 2-3 points instead of evenly supporting them with clearance for oil film.

Burnishing forces the bushings to round and gives even support with even oil film.


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## teK-- (Dec 3, 2011)

Dougal said:


> Burnishing isn't all about sizing bushings. It's largely about shaping bushings.
> Many go in slightly egg shaped which means they are contacting the stanchions at 2-3 points instead of evenly supporting them with clearance for oil film.
> 
> Burnishing forces the bushings to round and gives even support with even oil film.


Makes sense.

Why this not a part of the assembly process at the factory astounds me.

It results in a huge variation in performance depending whether you get a "good" one or not.

Sadly, I did not get a good one and ended up replacing/honing the bushings and replacing the CSU as they had wear marks from the too-tight bushings.


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## digev (Mar 7, 2019)

teK-- said:


> Makes sense.
> 
> Why this not a part of the assembly process at the factory astounds me.
> 
> ...


You touch on something interesting because most people would think that resizing will probably decrease the service life of bushings where in reality it's quit the opposite and it could prevent wearing out the shaft or stanchion in our case.

Too tight or too loose is bad, in between is good.

A cool study has been published about that

The Tribological Performance of Self-Lubricating Bearings Following Secondary Sizing Adjustment (Burnishing)



> An investigation was conducted to evaluate the effect of burnishing on tribological performance on a variety of self-lubricating bearings [...] Significant burnishing levels were achieved with no measurable reduction in polymer bearing wear life


Source: https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=2888&context=icec

The result? (Spoiler Alert!)



> Wear data showed that bearing life of a lead free PTFE / CaF2 bushings at all burnishing levels was the same or greater than the baseline PTFE bushing material in the unburnished state


That's good to know 

In the same document they showed the relation between the diameter of the burnishing tool and the final ID change, the 0.07mm tool seems to match the belief that you will end up with +0.02mm more clearance (not real clearance because we don't know the real stanchion diameter)


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## JB450 (Mar 31, 2019)

teK-- said:


> Why this not a part of the assembly process at the factory astounds me.


Time and money (profit). Simple.

The manufacturer does not care about burnishing bushes at the factory because the time spent burnishing at the factory can be spent assembling the next fork. It's an assembly line. Not a suspension workshop.

Sent from my INE-LX2 using Tapatalk


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## digev (Mar 7, 2019)

teK-- said:


> Why this not a part of the assembly process at the factory astounds me.
> 
> It results in a huge variation in performance depending whether you get a "good" one or not.


Let's have a look at some bushing data provided by SKF

Bushing dimensions

ID: 35mm
Wall Thickness: 1.970mm <> 2.005mm
Shaft: 34.950mm <> 34.975mm
Operating clearance: 0.015 <> 0.135mm

They already tell you that a 0.035mm ID variation can occur and still be considered OK to pass the QC

Now imagine a bang on 35mm stanchion inside an «approved» -0.035mm bushing ... From a mass manufacturing point of view it's fine ... even if it's not ideal

Now if we throw roundness, alignment and stanchions variations as well into the mix, what are the odds of having a good fit? LOL

They can end up being OK (most people don't notice or care) but the chances of having everything lined up is very slim! You could estimate yourself lucky if all those parameters were to play nice with each other 

In the end it kinda works, the fork goes up and down and that's what people expect, it's just not optimized or ideal! (Worst case it's causing issues)

That I could understand ... but what I find unfortunate is riders looking for ways to improve their ride quality usually end up buying bullshit upgrades because they just don't know how much of a difference it makes!

Source: SKF - Metric PTFE composite bushings - shaft and housing tolerances, operating clearance


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## Rey112 (Jan 1, 2021)

I have taken the bushings out of the RS 35 and I can measure them.


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## CCS86 (Jan 6, 2020)

Rey112 said:


> I have taken the bushings out of the RS 35 and I can measure them.


An uninstalled bushing won't tell you much though. It will change significantly in size and shape (roundness) once installed, due to the press fit.

Sent from my Pixel 4 using Tapatalk


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## digev (Mar 7, 2019)

CCS86 said:


> An uninstalled bushing won't tell you much though. It will change significantly in size and shape (roundness) once installed, due to the press fit.


True and measuring (once the bushings are back into the fork) will only tell you what you already know or witnessed through troubleshooting


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## digev (Mar 7, 2019)




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## Rey112 (Jan 1, 2021)

Is this bushings push roller tapered or not?


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## 294037 (Jun 30, 2006)

digev said:


> Let's have a look at some bushing data provided by SKF
> 
> Bushing dimensions
> 
> ...


Good points, and you will find most manufacturers size their bushings after installation, but a) they won't use as large of a tool to allow for faster work, more margin for error and less likely to feel "loose" on the shop floor. And b) tools wear, so the early production might feel great but later ones are more snug


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## 006_007 (Jan 12, 2004)

I would be all about doing this but the associated costs of doing it on my own fork (tools) is cost prohibitive. 

And I don't think I have anyone in Vancouver/whistler that will touch manitou (maybe I could reach out to vorsprung on the topic if I cover the manitou decals on the lowers lol).

Is there anyone in the states that if I purchased a brand new mezzer that they would do it prior to shipping?


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## Dougal (Jan 23, 2004)

006_007 said:


> And I don't think I have anyone in Vancouver/whistler that will touch manitou (maybe I could reach out to vorsprung on the topic if I cover the manitou decals on the lowers lol).


No-one except Zac Smith at Smithtech who distributes Manitou, Hayes, SunRingle and Protaper?





HOME | smithtech







www.smithtechbike.com





He's in North Vancouver


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## 006_007 (Jan 12, 2004)

Dougal said:


> No-one except Zac Smith at Smithtech who distributes Manitou, Hayes, SunRingle and Protaper?
> 
> 
> 
> ...


Zac moved to Calgary a few years ago - when i picked up my McLeod from him he was literally packing his house up to leave.

And I am not certain if he does things that are being discussed in here.


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## mike156 (Jul 10, 2017)

Talk to your local shops to see if they do this in general and then ask if you could buy them the 37mm head for payment or something.

If nothing else, buy the $150 tool between you and a couple riding buddies.


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## 006_007 (Jan 12, 2004)

mike156 said:


> Talk to your local shops to see if they do this in general and then ask if you could buy them the 37mm head for payment or something.
> 
> If nothing else, buy the $150 tool between you and a couple riding buddies.


Will see if I can track purchase something for under 200 (with head). It can stay on the wall with the headset press that rarely is used lol.


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## Dougal (Jan 23, 2004)

006_007 said:


> Zac moved to Calgary a few years ago - when i picked up my McLeod from him he was literally packing his house up to leave.
> 
> And I am not certain if he does things that are being discussed in here.


Interesting, I didn't know that and neither does his website!

The mezzers have been pretty good regarding bushing sizing. The burnishing usually goes "yep, that's good".
I had a few tight Mattocs though.


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## teK-- (Dec 3, 2011)

Some great info being shared in this thread, thanks everyone


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## teK-- (Dec 3, 2011)

JB450 said:


> Time and money (profit). Simple.
> 
> The manufacturer does not care about burnishing bushes at the factory because the time spent burnishing at the factory can be spent assembling the next fork. It's an assembly line. Not a suspension workshop.
> 
> Sent from my INE-LX2 using Tapatalk


I understand why they don't do it, but what I mean to say is I am shocked and disappointed that they could leave it out of the finishing process.

It's just like the Fox negative springs being stuffed with excessive grease. The manufacturers should spend less money on spruiking the incremental improvements to their springs every year, and more on manufacturing costs. If they cannot even get the basics of assembly correct, they aren't giving their customers a chance to get the expected performance out of their purchase.


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## JB450 (Mar 31, 2019)

teK-- said:


> I understand why they don't do it, but what I mean to say is I am shocked and disappointed that they could leave it out of the finishing process.
> 
> It's just like the Fox negative springs being stuffed with excessive grease. The manufacturers should spend less money on spruiking the incremental improvements to their springs every year, and more on manufacturing costs. If they cannot even get the basics of assembly correct, they aren't giving their customers a chance to get the expected performance out of their purchase.


I totally agree 

Sent from my INE-LX2 using Tapatalk


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## Rey112 (Jan 1, 2021)

[QUOTE = "digev, post: 14925443, członek: 849257"]
Jeśli ktoś szuka nowych tulei do swojego 35 mm RS, ND Tuned sprzedaje coś ciekawego!

Są wykonane przez firmę Igus i nie mają żadnych metalowych części, więc nawet jeśli się zużyją, nie uszkodzą (metal na metalu) kłonic, takich jak zwykłe pokryte PTFE, które zwykle mają maksymalną powierzchnię ścieralną 0,06 mm w porównaniu z 0,25 mm dla Igusa


















Kosztują 44 € (50 $) + wysyłka

Źródło: ND Tuned Bushing Kit ROCKSHOX 35

Dane techniczne Igus Iglidur J3: iglidur® J3, sleeve bearing, mm

4 powody, dla których warto wymienić tuleje wyłożone PTFE: - 4 Reasons To Replace PTFE-lined Bushings

nie dbamy o wagę, więc mamy tylko 3 dobre powody 
[/ZACYTOWAĆ]
These bushings will not smash and catch slack? Anyone using them?


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## digev (Mar 7, 2019)

Rey112 said:


> [QUOTE = "digev, post: 14925443, członek: 849257"]
> Jeśli ktoś szuka nowych tulei do swojego 35 mm RS, ND Tuned sprzedaje coś ciekawego!
> 
> Są wykonane przez firmę Igus i nie mają żadnych metalowych części, więc nawet jeśli się zużyją, nie uszkodzą (metal na metalu) kłonic, takich jak zwykłe pokryte PTFE, które zwykle mają maksymalną powierzchnię ścieralną 0,06 mm w porównaniu z 0,25 mm dla Igusa
> ...


Dude, many people are probably willing to help (myself included) but you should start writing in English please otherwise you're making the task difficult! Even a Google translate would do


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## digev (Mar 7, 2019)

All these pics come from dedicated suspension service centers!!


































They are out there ... next time you get your fork serviced/retuned ask if they can check and if necessary resize/reshape your bushings to reduce friction ... if the answer is NO or they don't know why you're asking the question ... you know what to do


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## Rey112 (Jan 1, 2021)

digev said:


> Dude, many people are probably willing to help (myself included) but you should start writing in English please otherwise you're making the task difficult! Even a Google translate would do


My point was whether plastic bushings (without a metal frame) will not knead / deform themselves, which will cause excessive slack in some time.


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## digev (Mar 7, 2019)

Rey112 said:


> My point was whether plastic bushings (without a metal frame) will not knead / deform themselves, which will cause excessive slack in some time.


Can't say for sure but ND Tuned are known for their quality and I don't see them sell a product that's not reliable or causing issues ... so in short, they've tested those bushings and think they're worth selling! If I had to change mine I would give them a go


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## Rey112 (Jan 1, 2021)

-Are there any opinions of their owners?


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## digev (Mar 7, 2019)

My mate's 2016 Pike is now as smooth as it can be ... it wasn't horrible like others (Thank god after 4 years of riding) but it definitely made a difference and he felt it straight away on the trails ... that feel is here to stay


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## link1896 (Jul 13, 2007)

digev said:


> All these pics come from dedicated suspension service centers!!
> 
> 
> 
> ...


That bushing installation tool is very cool. I will be copying that.


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## Rey112 (Jan 1, 2021)

Would bronze or bronze and POM (composite) bushings be suitable for a shock absorber?


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## TazMini (Jun 21, 2019)

Been scrolling past this thread for months. Finally read it and just placed my order with Oliver for a set of tools. Used to race cars and off the shelf suspension always needed reworking, so this makes sense. 


Sent from my iPhone using Tapatalk


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## 294037 (Jun 30, 2006)

link1896 said:


> That bushing installation tool is very cool. I will be copying that.


Thats the BBI tool like I have. If you can I would recommend a threaded design instead of a slide hammer like this


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## 006_007 (Jan 12, 2004)

Prior to ordering the tool from Oliver are we measuring our stanchions first (top-middle-bottom)? Or are we just reheating .07 over what we believe our stanchion is sized at?

Or is everyone participating in this in the business of suspension servicing or a home mechanic?


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## trel (Aug 7, 2018)

I'm a home bike mechanic for a hobby (auto mechanic trade). I've done a bunch of mods on my own forks to get them feeling less harsh with mixed but over all good success, and learned a lot along the way.

Recently after a discussion with Oliver I ordered a burnishing tool with a 35.07mm and 35.10mm head. Due to the time and cost of sending it to me in Australia, I got both heads straight away to feel the results for myself. The cost is worth it to me as I have 3x 35mm stanchion Rockshox forks (2 Lyriks and 1 Pike) which I have done, and Yari and Lyrik belonging to friends that I will do soon.

I did a few passes with 35.07 on each fork, they all felt better. Then a few at 35.10 just because I could. The forks were all super tight and now feel a lot better. Free to get moving off the top. No binding up/ notchy platform feel through the travel. I can use more PSI without harshness and have more support through the travel. Resizing bushings will be the first mod I do to any fork in the future.


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## digev (Mar 7, 2019)

TazMini said:


> Been scrolling past this thread for months. Finally read it and just placed my order with Oliver for a set of tools. Used to race cars and off the shelf suspension always needed reworking, so this makes sense.


It does make a lot of sense, you'll see when you get to use the tool but even more after riding the fork once done 

The result will always be positive but expectations can vary depending on whether or not the bushings were a major issue or just needed some massaging!

That's why the first step would be to strip the fork and slide the uppers into the lowers with nothing else to assess the need for burnishing! The pros working in the suspension business and seeing hundreds could probably tell us what the chances are on average (and probably based on brands/models) but I wouldn't be surprised if the answer was «very often»



JohnnyC7 said:


> Thats the BBI tool like I have. If you can I would recommend a threaded design instead of a slide hammer like this


Easier to use, more precise or just a preference?



006_007 said:


> Prior to ordering the tool from Oliver are we measuring our stanchions first (top-middle-bottom)? Or are we just reheating .07 over what we believe our stanchion is sized at?
> 
> Or is everyone participating in this in the business of suspension servicing or a home mechanic?


Both! But it definitely comes from the suspension business and the need for that tool

No need to measure but you could ask Oliver why he believes +0.07mm is the magic number 

Some people have asked for an additional +0.10mm and are happy too! I think the Fox tool comes with 2 dies per stanchion size ... one is the exact diameter, so +0.00mm (probably to test or something) and the other one is a +0.10mm, so ....

In a perfect world accurately measuring everything and making the tool to create an optimal match would be ideal but in reality it would probably make just a small difference compared to doing it or not



trel said:


> The forks were all super tight and now feel a lot better. Free to get moving off the top. No binding up/ notchy platform feel through the travel. I can use more PSI without harshness and have more support through the travel. Resizing bushings will be the first mod I do to any fork in the future.


Exactly that, Amen


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## CrozCountry (Mar 18, 2011)

0.2286 mm Tolerance? Thats huge.
Also the range of 0.0381 - 0.2286 is not confidence inspiring. Do they mean 0.0381 for a new fork and 0.2286 for a dead fork? I hope forks don't come out of the production line in 0.0381 - 0.2286 range.

Next time I service the fork I will try sliding it, now you got me interested.


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## spo0n (Nov 7, 2020)

trel said:


> I'm a home bike mechanic for a hobby (auto mechanic trade). I've done a bunch of mods on my own forks to get them feeling less harsh with mixed but over all good success, and learned a lot along the way.
> 
> Recently after a discussion with Oliver I ordered a burnishing tool with a 35.07mm and 35.10mm head. Due to the time and cost of sending it to me in Australia, I got both heads straight away to feel the results for myself. The cost is worth it to me as I have 3x 35mm stanchion Rockshox forks (2 Lyriks and 1 Pike) which I have done, and Yari and Lyrik belonging to friends that I will do soon.
> 
> I did a few passes with 35.07 on each fork, they all felt better. Then a few at 35.10 just because I could. The forks were all super tight and now feel a lot better. Free to get moving off the top. No binding up/ notchy platform feel through the travel. I can use more PSI without harshness and have more support through the travel. Resizing bushings will be the first mod I do to any fork in the future.


Hey mate you in melbourne by any chance


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## JB450 (Mar 31, 2019)

trel said:


> I'm a home bike mechanic for a hobby (auto mechanic trade). I've done a bunch of mods on my own forks to get them feeling less harsh with mixed but over all good success, and learned a lot along the way.
> 
> Recently after a discussion with Oliver I ordered a burnishing tool with a 35.07mm and 35.10mm head. Due to the time and cost of sending it to me in Australia, I got both heads straight away to feel the results for myself. The cost is worth it to me as I have 3x 35mm stanchion Rockshox forks (2 Lyriks and 1 Pike) which I have done, and Yari and Lyrik belonging to friends that I will do soon.
> 
> I did a few passes with 35.07 on each fork, they all felt better. Then a few at 35.10 just because I could. The forks were all super tight and now feel a lot better. Free to get moving off the top. No binding up/ notchy platform feel through the travel. I can use more PSI without harshness and have more support through the travel. Resizing bushings will be the first mod I do to any fork in the future.





trel said:


> Recently after a discussion with Oliver I ordered a burnishing tool with a 35.07mm and 35.10mm head. Due to the time and cost of sending it to me in Australia, I got both heads straight away to feel the results for myself.


Time and cost of shipping to Australia was the reason why I made my own 35.08mm tool.

Handy having a lathe at work and plenty of stainless offcuts.

Sent from my INE-LX2 using Tapatalk


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## karpiel (Aug 27, 2010)

006_007 said:


> Prior to ordering the tool from Oliver are we measuring our stanchions first (top-middle-bottom)? Or are we just reheating .07 over what we believe our stanchion is sized at?
> 
> Or is everyone participating in this in the business of suspension servicing or a home mechanic?


Hope to be starting my own business within next few months, I have the tool on order from Oliver.


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## digev (Mar 7, 2019)

karpiel said:


> Hope to be starting my own business within next few months, I have the tool on order from Oliver.


Good on you! All the best 

Where are you in the world?


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## karpiel (Aug 27, 2010)

digev said:


> Good on you! All the best
> 
> Where are you in the world?


Thanks buddy, I'm in Ireland.


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## digev (Mar 7, 2019)

Quick clarification about the die/head diameter and the final result!

If we are to believe the guys at GGB Bearing Technology and our dear friends at SKF (2 reliable sources and pro tribologists), if you use a 0.07mm head you will increase the clearance by 0.02mm but if you use a 0.1mm head it will double that number and give you 0.04mm clearance (+/-) Who would have thought ...



















So we can avoid that situation!


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## trel (Aug 7, 2018)

spo0n said:


> Hey mate you in melbourne by any chance


Nah, I'm in Perth. How's the riding over there?



JB450 said:


> Time and cost of shipping to Australia was the reason why I made my own 35.08mm tool.
> 
> Handy having a lathe at work and plenty of stainless offcuts.


Nice one, how's the fork feeling after? It didn't take as long to get here as I expected after all. I wasn't in a hurry though. If I want to get another head say for fox 36 or whatever, i'll get it made locally. I don't have access to a lathe and a bit of a noob at machining. This would be a really good project for learning how to use a lathe well.


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## JB450 (Mar 31, 2019)

trel said:


> Nah, I'm in Perth. How's the riding over there?
> 
> Nice one, how's the fork feeling after? It didn't take as long to get here as I expected after all. I wasn't in a hurry though. If I want to get another head say for fox 36 or whatever, i'll get it made locally. I don't have access to a lathe and a bit of a noob at machining. This would be a really good project for learning how to use a lathe well.


I had one bush that was particularly deformed from installation.

So I run the tool through that one 4 times and the other bushes 3 times.

The difference was very noticeable. Never thought the fork was that bad, but after burnishing it is great.

Sent from my INE-LX2 using Tapatalk


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## digev (Mar 7, 2019)

Quick Bonus!

A short video filmed last fall with my good friend Greg in the Maritime Alps (South East of France)! OK OK it has nothing to do with bushings  but you'll understand why they have to be in tip top shape so you can enjoy the moment and forget all about the technical side of our beloved rigs!









Video: Showcasing the Very Best Trails of the Maritime Alps - Pinkbike


Exploring the birthplace of some of the greatest MTB riders in the world.




m.pinkbike.com





Because bikes are just a means to an end, sharing stoke with buddies and overall good time outdoors 

PS: Come ride with us


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## digev (Mar 7, 2019)

Guys, I made a mistake about one of the previous posts

I wrote that a 0.07mm head would increase the bushing ID by 0.05mm but it isn't true ... it will only be increased by 0.02mm (as stated yesterday and based on 2 different graphs)

I don't know why I got those results mixed up but it woke me up last night LOL 

PTFE is quit "elastic" and for example if you burnish it with a 0.02mm head it will go back to it's original state, no internal diameter changes at all! (see posted graph)

And the word "clerance" is misleading because if we don't measure the stanchion diameter we don't really know what the real clearance will be! it will be increased, that's for sure ... but if we don't measure we won't know by how much. Sorry about that, now I hope it's clear(er)

FYI: I'll edit the first post to correct it!


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## digev (Mar 7, 2019)

Based on the Fox documentation and the burnishing Tool they sell it makes sense now.

They sell the +0.1mm heads for their stanchions diameters (32/34/36/40) (and soon 38 I guess)

+0.1mm will increase the bushing ID by 0.04mm!

And they state:

*Correct bushing tolerance is a diametric clearance of 0.0381mm - 0.2286mm*

So their tool will give you what they believe is the minimum diametric clearance they preconise! Not a coincidence right?

source: Bushing Technology & Inspection


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## digev (Mar 7, 2019)

CrozCountry said:


> 0.2286 mm Tolerance? Thats huge.
> Also the range of 0.0381 - 0.2286 is not confidence inspiring. Do they mean 0.0381 for a new fork and 0.2286 for a dead fork? I hope forks don't come out of the production line in 0.0381 - 0.2286 range.
> 
> Next time I service the fork I will try sliding it, now you got me interested.


I'd say out of the factory the are way tighter than the 0.0381mm minimum tolerance advertised on their website, otherwise we wouldn't have any issues with so called tight bushings 

Proof is, when burnishing with a +0.07mm head and theoretically increasing the bushing internal diameter by just +0.02mm it makes a great difference on the trails and we are still under or really close to the advertised 0.0381mm clearance ... and that's after burnishing. Now I can't imagine having 7x that clearance and be OK with the way it works, but who knows ... as always, if you don't measure you're guessing!


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## link1896 (Jul 13, 2007)

After seeing a 0.03mm difference between stanchions in the same crown, I’ll be measuring everything and will be turn up a range of heads on a case by case basis, fully appreciating Dougal’s comments that roundness of bushing is a key benefit. 

I see an internal micrometer capable of deep bore measurements at 30-40mm in my future. 

Btw, Tek good to see you over here!


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## mike156 (Jul 10, 2017)

I can appreciate the desire to come up with the ideal size. But from experience, I'm thinking just giving the bushing an extra pass with the burnishing tool can make up for that +/-0.02mm difference.

I'd go ahead and do 2 passes to start with and then check fitment of each stanchion individually. If one is still tight, give it another pass and check again. If they both move well individually, check both at the same time. If it's still tight, give each one another pass.

It gets looser with each pass, at least up to five or so passes in my experience. It's not a once through and done type of thing.


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## digev (Mar 7, 2019)

Got another friend's Pike today as I was looking to do a little experiment and measure something on an (very) sticky unburnished fork ... Get ready ??‍♂

I've put the fork (just the chassis, CSU + Lowers) upside down onto a bathroom scale and with the stanchions inside the first set of bushings I pressed on it and it took about 3kg of force to start moving and keep moving.

Now with the stanchions inside the second set of bushings as well I started to gently press on it and I pressed, and I pressed, and I pressed and just over the 10kg mark it broke free and by applying the same pressure I got to the bottom and on average the scale was recording between 3kg and 6kg (Hmmm friction)

It's obviously very unscientific and flawed but it gives a rough idea of a real test you could do at home and record the break-away force needed to set the fork in motion (and overcome the stick-slip) and what is needed to keep it moving (with a lot of friction). Made a slow-mo of it because it's not easy to get what's happening in real time as the scale is oscillating rapidly but its lacking light and stability so I'll make another soon to share it with you.

FYI, the air spring from the same fork (1st gen solo air shaft with Luftkape and upgraded seal) took about 1Kg of force to break-away and keep moving inside the seal head!

Now I need to burnish it and re-record everything to compare ... stay tuned 

I think my fork was around 300g after burnishing to start and keep moving but I'll double check next time I service it!


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## digev (Mar 7, 2019)

Quick tip!

If after burnishing you put you fork upside down and the lowers slide into the uppers under their own weight then the amount of force required to overcome the frictional force are now lower that your lowers weight

Ex: 27.5 Pike lowers are about 650g

Might be stating the obvious but here you go 

No wonder why it's so smooth and tracking the ground like crazy when you compare the before vs after


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## digev (Mar 7, 2019)

Found an article about Ohlins and bushings ... interesting take on the subject 

I know, I know they used to make forks with super tight bushings, but here's why they did ...



> So the main chassis of the fork has been improved, but so have the bushings, lubrication oil and seals. New wiper seals from SKF, a new lubricant, and bushings with more play - "*Hang on, more bushing play? Do I want that?" Well, yes you do, to a point - Ohlins say their moto forks have much more play in the bushings, it means a smoother suspension action under load*, but also creates a 'loose headset' type feeling, but this is harder to feel in the car park with the huge weight and inherent sag of an MX bike. *They say it's harder to convince mountain bikers that this is a good thing and the older versions were too tight to give consumers the feeling they wanted.* Working with their racing teams, they say that a happy medium has been reached with the new bushings. This should also help stop sticky forks; I had a RXF36 coil last year which became terribly sticky after a few weeks of riding, and there were many complaints from consumers with OEM spec forks.












source: First Ride: Ohlins New RXF36 Trail Fork & TTX Air Shock - Pinkbike


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## Rey112 (Jan 1, 2021)

Any ways to reduce solo air friction?


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## Nikola777 (Jun 4, 2017)

Hi there!
I started to interested in the "Fork Bushing Sizing Tool".
And decided to make a tool.
What material would be the best to made a head (the part which expands the bushing)?


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## CCS86 (Jan 6, 2020)

Nikola777 said:


> Hi there!
> I started to interested in the "Fork Bushing Sizing Tool".
> And decided to make a tool.
> What material would be the best to made a head (the part which expands the bushing)?


Hardened alloy steel, or tool steel, would probably be longest wearing, but would need to stay coated in oil to prevent corrosion.

As long as you are very clean when working with the tool, stainless steel is probably your best bet overall. I would avoid anything in annealed condition.

Sent from my Pixel 4 using Tapatalk


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## digev (Mar 7, 2019)

Quick proof of concept

Nothing fancy or very accurate but the point was to (try) to measure the friction force before and after burnishing and eventually find out how the overall friction is spread/shared across the other components in the fork ...










I used a kitchen scale! See, not very scientific and no fancy tools but as you'll see it's enough to gather enough info to get a rough idea of what's going on

I got the following results after testing 10 times each component (dry, no lubrication) and wrote down the average values (rounded for simplicity's sake)

*Damper (Charger 1 with upgraded seal)*

Static: 200g
Dynamic: 100g

*Air spring seal head (solo air with o-ring)*

Static: 1Kg
Dynamic: 800g

*Air spring piston (Vorsprung Luftkape)*

Static: 2kg
Dynamic: 1.5kg

*Stock Wiper seals (1 year old / 1 seal only)*

Static: 1Kg
Dynamic: 1Kg

*ND Tuned Wiper seals (brand new / 1 seal only)*

Static: 1Kg
Dynamic: 800g

*Bushings (before burnishing)*

Static: 10kg
Dynamic: 3kg to 6kg during the same measurement (variations occur due to the very unpredictable nature of friction)

*Bushings (after burnishing with a +0.07mm head)*

Static: 600g
Dynamic: 600g

Overview: Streamable Video
Close range: Streamable Video


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## digev (Mar 7, 2019)

28 Bikes Bottomed Out In Ultra Slo Mo (1000 FPS)

Source: Video: 28 Bikes Bottomed Out In Ultra Slo Mo (1000 FPS) - Pinkbike

You know what to look for


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## Preston67 (Mar 20, 2008)

So during your tests you were pushing down on the fork and recording the approximate delta on the scale ? 
When testing the seal head/damper/air piston, you had just these components attached to the lowers ? Ie the upper crown/stanchions were not part of the test ? (because if they were then obviously the bushings would be part of it). 
that may all seem obvious just trying to understand exactly what you were doing.

Thanks for the effort those are really interesting results, and clearly show the bushings are the most important by an order of magnitude. Also that the wipers (including aftermarket wipers) probably don't make much overall difference. 

the only thing missing is the contribution of axle clamping to stiction (which will of course vary for different forks/hubs). 

I doubt there is much we can do to reduce friction in those other components, but its interesting to ponder how much the improved feel of a coil is due to its inherent qualities vs just reducing stiction. 

(I have a situation where I have an Avalanche open bath conversion, and the damping rod is perfectly fine. But when I bolt it down to the lower leg, it is not centered at the top of the leg. IOW I think the bottom surface inside of my lower leg is not flat. I can tell this adds binding and friction to the assembly but wasn't sure what to do about it and have been living with it. But when I rebuild the fork and burnish the bushings I will attempt to build a tool to try and flatten that out as I've been inspired by this threa).


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## digev (Mar 7, 2019)

*


Preston67 said:



So during your tests you were pushing down on the fork and recording the approximate delta on the scale ?

Click to expand...

*I've put the following on the scale

The CSU + Lowers + a block of wood + a metal bracket = 2422g

Once you know the total weight, you just let the CSU slide into the lowers under it's own weight and record the highest value (in-slow mo because it's easier to read) above the static weight, the difference is friction ... in our case, stanchions sliding against the bushings! The highest value recorded was just under 3kg, so 3000 - 2400 = 600g  I knew it was under 760g because it's the CSU's weight

*


Preston67 said:



When testing the seal head/damper/air piston, you had just these components attached to the lowers ? Ie the upper crown/stanchions were not part of the test ? (because if they were then obviously the bushings would be part of it).
that may all seem obvious just trying to understand exactly what you were doing.

Click to expand...

*Each component was tested on it's own and pushed against the scale (10 times)

*


Preston67 said:



Thanks for the effort those are really interesting results, and clearly show the bushings are the most important by an order of magnitude. Also that the wipers (including aftermarket wipers) probably don't make much overall difference.

Click to expand...

*Thanks I appreciate, I was genuinely being curious about the role other components play into the whole friction game. Now you could increase the speed, side load etc ... but it would probably tell you the same story! If bushings are a problem, no need to go any further without fixing it first ... otherwise you will only micro-optimize

*


Preston67 said:



I doubt there is much we can do to reduce friction in those other components, but its interesting to ponder how much the improved feel of a coil is due to its inherent qualities vs just reducing stiction.

Click to expand...

*It depends. When RS released the Debonair it definitely helped but if we compare those numbers to my real life "experiment" you could save about 2.3Kg of running/dynamic friction if you were to switch to a coil vs 1kg when upgrading a 2018 air spring for 2019 air spring ... so going to a coil spring is still a good move if you do decide to lower the friction but ONLY after checking that your bushings are OK! Just for fun if we imagine for a second that my mate (who owns the test fork I just wrote about) wanted to switch to a coil after getting rid of the ridiculously high static and dynamic friction caused by the bushings he would reduce the overall static friction by (2800g vs 5800g) 51% ... that's huge.

Now if he was to swap to a coil but leave the bushings like that (in bad shape) he would only reduce the overall friction by (12200g vs 15200g) 20% that's better, but it's too bad he skipped the main culprit  and it's still 80% more overall static friction than coil + resized bushings (2800g vs 12200g) personally I would do both and I did! LOL 










source: Rockshox makes DebonAir much smoother on new 2019 Lyrik, Yari, Pike & Revelation - Bikerumor

*


Preston67 said:



the only thing missing is the contribution of axle clamping to stiction (which will of course vary for different forks/hubs).

Click to expand...

100% agree with you! I need to work on that too ...

EDIT: I forgot to had 2x 1Kg for the wiper seals in my calculation about the overall static friction scenario (air vs coil) (instead of x1 initially)! It's been fixed now*


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## karpiel (Aug 27, 2010)

Preston67 said:


> So during your tests you were pushing down on the fork and recording the approximate delta on the scale ?
> When testing the seal head/damper/air piston, you had just these components attached to the lowers ? Ie the upper crown/stanchions were not part of the test ? (because if they were then obviously the bushings would be part of it).
> that may all seem obvious just trying to understand exactly what you were doing.
> 
> ...


Dude, I have the same issue with the Avalanche damper in my 36, its is however an issue with the lower casting and NOT damper, Ava stuff is allways spot on.


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## digev (Mar 7, 2019)

karpiel said:


> Dude, I have the same issue with the Avalanche damper in my 36, its is however an issue with the lower casting and NOT damper, Ava stuff is allways spot on.


What seems to be the problem?


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## Preston67 (Mar 20, 2008)

The bottom surface inside the damper fork leg is evidently not flat, meaning when you bolt down the Avalanche damper rod at the bottom, it is not concentric at the top. Since the bottom surface of the avalanche damper is flat, this must mean the internal fork leg surface is not machined flat. 
I need to look at the stock damper to determine why this wouldn't be a problem with it.


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## 294037 (Jun 30, 2006)

Preston67 said:


> The bottom surface inside the damper fork leg is evidently not flat, meaning when you bolt down the Avalanche damper rod at the bottom, it is not concentric at the top. Since the bottom surface of the avalanche damper is flat, this must mean the internal fork leg surface is not machined flat.
> I need to look at the stock damper to determine why this wouldn't be a problem with it.


I remember Avalanche used to have a "how to" guide to fix this by taking a stanchion (ie for a dual crown fork) with the blank spring side top cap installed, glue a small piece of sandpaper to the top and insert it upside down in to the lowers. The bushings will hold it square so you can sand it smooth.

*note* This is really old advice and may not be AVA's own recommendation these days!


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## 294037 (Jun 30, 2006)

digev said:


> Quick proof of concept
> 
> Nothing fancy or very accurate but the point was to (try) to measure the friction force before and after burnishing and eventually find out how the overall friction is spread/shared across the other components in the fork ...
> 
> ...


Nice work! Were the bushings dry or with oil?


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## half_man_half_scab (Mar 7, 2006)

So what’s the proper procedure for sizing the lower bushings? Do you press the tool through both the upper and lower an equal number of times? Specifically, what is the procedure when the upper is sized correctly, but the lower needs more work?


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## 294037 (Jun 30, 2006)

half_man_half_scab said:


> So what's the proper procedure for sizing the lower bushings? Do you press the tool through both the upper and lower an equal number of times? Specifically, what is the procedure when the upper is sized correctly, but the lower needs more work?


If the upper bushing is already sized OK then pushing the tool through once isn't a problem since the interference will be less


----------



## digev (Mar 7, 2019)

JohnnyC7 said:


> Nice work! Were the bushings dry or with oil?


Thanks  I tried to remove as much as I could but it's not easy to wipe the bottom ones.


----------



## digev (Mar 7, 2019)

Super sticky Fox 32










BEFORE



https://shorturl.at/zSU48



AFTER



https://shorturl.at/muwRS



Source: @vitaliisergeev


----------



## half_man_half_scab (Mar 7, 2006)

JohnnyC7 said:


> If the upper bushing is already sized OK then pushing the tool through once isn't a problem since the interference will be less


So, presuming the die on the head of the tool is the right size, you wouldn't be able to over do it with burnishing?


----------



## digev (Mar 7, 2019)

half_man_half_scab said:


> So, presuming the die on the head of the tool is the right size, you wouldn't be able to over do it with burnishing?


That's correct! Especially since the first 0.02mm do nothing as the PTFE material will spring back to its original internal diameter and shape ... in short it's not stressed enough to get deformed permanently! FYI the top bushings are usually tighter than the bottom ones ...


----------



## Dougal (Jan 23, 2004)

You can't over-burnish by hand. You could if it were powered.


----------



## half_man_half_scab (Mar 7, 2006)

Awesome, good info, thanks. I’ll report back on potentially how bad it is with the Zebs once the tools get here.


----------



## nicolasswid (Apr 15, 2014)

I struggled during months with my faulty SID 2017 until it felt somewhat acceptable in term of friction. And then I bought a used 2017 fox 34 Factory FIT4 (does not have Evol spring).
The difference is just ridiculous, even if the fox have not been maintained for one year, it is so smooth and ride seems like a magic carpet, it is night and day. Even in the small rocks, the difference is noticeable, and the feel is much better (equal or better friction than my Lefty Hybrid when well maintained).
I was not able to tune rebound before, simply because the fork was so crappy it was impossible to feel something.
Not sure if it's thanks to the kashima coating or to the fact the manufacturing tolerances are very good, but it makes a world of difference


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## B. Rock (Mar 9, 2011)

Long thread to read through, but in short - I rode a demo bike that had 2 seasons of demo'ing on it and was just about to be retired. However, the fox 36 on the front felt absolutely amazing compared to the luftkappe'd pike I was coming off which really took me by surprise. I'm wondering if all the use had basically burnished the bushings as described here? I've been playing with a couple forks that just don't feel anywhere close to how that one 36 felt, including another 36, and it's driving me insane trying to chase that white rabbit.


----------



## digev (Mar 7, 2019)

Your fork can be brand new and not up to the task just yet ... like this straight out of the box Rockshox SID

Check the difference before and after burnishing!










BEFORE


https://shorturl.at/hzIN7



AFTER


https://shorturl.at/oyANP


----------



## digev (Mar 7, 2019)

B. Rock said:


> I'm wondering if all the use had basically burnished the bushings as described here?


It's definitely a possibility! Used forks usually feel better for that exact reason (as long as they have been serviced properly)


----------



## sstefanov (Sep 18, 2005)

So, here is my experience burnishing the bushings on a 2019 Fox 34 Performance Elite, 29" models. The fork is about 18 months old, ridden about 7-8 hours per week on average. The fork actually worked quite well after Luftkappe and Fractive tune of the damper, but I was curious on how were the bushings. 

I ordered the tool at a local machine shop and got two heads - one 34.00 the other 34.07. The tools came spot on (measured with micrometer and good quality calipers). My stanchion tubes are 33.98mm all the way.

Initially stared with the 34.00 head, but it did drop quite easily through both upper and lower bushings on both legs. The 34.07 head was quite hard to pass through the upper bushings on both legs, requiring quite an effort. Lower bushings were noticeably easier to do, but still loosened up after 2-3 passes. In the end both upper and lower bushes felt almost the same, where I could push the tool through them with one hand.

As a test I slid both legs individually with the seals installed (did not want to waste a perfectly good set of SKF green seals), the lowers just fell off. With both legs in, the almost fall by themselves, requiring the slightest of touch with the pinkie finger. 

So the fork is back together and serviced. Hopefully the weather will improve and will be able to test the feel next week.


----------



## Preston67 (Mar 20, 2008)

> I ordered the tool at a local machine shop and got two heads


By which you mean you had a machine shop custom make you a tool ?


----------



## 006_007 (Jan 12, 2004)

Preston67 said:


> By which you mean you had a machine shop custom make you a tool ?


On the very first page of this thread it has a picture of a burnishing tool.

Is home mechanics can go and order one from Oliver at Blue Liquid Labs | An Oliver Majewski Project or you can go to a local machine shop and have them fabricate something similar. Or is you are fortunate enough to have a lathe you could make something yourself.

Biggest thing would be to ensure the head is machined from something like stainless steel so it does not wear fast. And also that it's measurement is accurate. Most people appear to be aiming for .07 over your target stanchion diameter.


----------



## sstefanov (Sep 18, 2005)

Preston67 said:


> By which you mean you had a machine shop custom make you a tool ?


Yep, a local machine shop made me the tool, based on a simple drawing I made. It just does not make sense to order a simple piece of metal from US to Europe

Stefan


----------



## digev (Mar 7, 2019)

https://shorturl.at/ftCN0


----------



## digev (Mar 7, 2019)




----------



## guim (May 2, 2006)

Jesse @dvo_newzealand is awesome! I've seen in another of his posts that he likes 36.04mm for the 36mm DVOs. 

My 3rd DVO Diamond feels much smoother that the 2 previous I've owned so maybe this one has better bushing sizing from the factory (I got it checked and serviced at SuspensionWerx in Canada when new but I don't think they burnish bushings on every fork coming in for a service). I'll inquire Oliver @ Blue liquid labs to know how much would a 35mm head + tool would be as this is something I'd like to do.


----------



## link1896 (Jul 13, 2007)

006_007 said:


> On the very first page of this thread it has a picture of a burnishing tool.
> 
> Is home mechanics can go and order one from Oliver at Blue Liquid Labs | An Oliver Majewski Project or you can go to a local machine shop and have them fabricate something similar. Or is you are fortunate enough to have a lathe you could make something yourself.
> 
> Biggest thing would be to ensure the head is machined from something like stainless steel so it does not wear fast. And also that it's measurement is accurate. Most people appear to be aiming for .07 over your target stanchion diameter.


No way the plastic bushings are wearing a 2011 T6 aluminium burnishing head when lubricated.

I ordered stock in 1045 steel and 2011 T6 aluminium before deciding 2011 T6 is more then adequate for this.

I assume to be on trend when burnishing bushings, one must use supergliss 100k


----------



## digev (Mar 7, 2019)

guim said:


> Jesse @dvo_newzealand is awesome! I've seen in another of his posts that he likes 36.04mm for the 36mm DVOs.
> 
> My 3rd DVO Diamond feels much smoother that the 2 previous I've owned so maybe this one has better bushing sizing from the factory (I got it checked and serviced at SuspensionWerx in Canada when new but I don't think they burnish bushings on every fork coming in for a service). I'll inquire Oliver @ Blue liquid labs to know how much would a 35mm head + tool would be as this is something I'd like to do.


Yeah I like his approach to suspension, he seems to care for riders and results instead of just being the middleman and sell «stuff»! Lots of very good suspension centers in NZ 










If he likes the +0.4mm clearance then he must be using the 36.10mm die


----------



## digev (Mar 7, 2019)

link1896 said:


> I assume to be on trend when burnishing bushings, one must use supergliss 100k


It's a rite of passage 

Joke aside, any oil you use in your lowers is good when burnishing ...

Apparently the «CGLP 68» used by Ohlins is good too, it's still a slideway oil ... but it should be compared to the Supergliss 68k to be fair! Still curious about the EXT HDT68SYNTH ... again 68 cSt at 40°C


----------



## The_Bob (Jan 16, 2018)

Still amazed at how supple my fork is after doing this. I had zero compression spikes on the weekend's ride, where before I'd have one or two per ride. I double checked sag before the ride and had to add 3 PSI more than my base settings, but the fork was flawless. Ate everything up from trail trash to some big landings whilst using almost all travel. This is by far the most effective work that can be done to a fork to improve performance that I have found. An absolute must do


----------



## Rey112 (Jan 1, 2021)

Can I grind the metal ring on the outside of the bushing instead of kneading it?



sstefanov said:


> So, here is my experience burnishing the bushings on a 2019 Fox 34 Performance Elite, 29" models. The fork is about 18 months old, ridden about 7-8 hours per week on average. The fork actually worked quite well after Luftkappe and Fractive tune of the damper, but I was curious on how were the bushings.
> 
> I ordered the tool at a local machine shop and got two heads - one 34.00 the other 34.07. The tools came spot on (measured with micrometer and good quality calipers). My stanchion tubes are 33.98mm all the way.
> 
> ...


Don't feel slack?


----------



## link1896 (Jul 13, 2007)

I have just found the most god awful example yet. 2020 fox 36. Will attempt to measure soon. North of 10kg to get lowers all the way up, with seals in place, air piston and damper out


----------



## digev (Mar 7, 2019)

link1896 said:


> I have just found the most god awful example yet. 2020 fox 36. Will attempt to measure soon. North of 10kg to get lowers all the way up, with seals in place, air piston and damper out


Hahahaha ... Yes they do exist, it's not a myth


----------



## digev (Mar 7, 2019)

*HIGH INTELLECT CO LTD* used to make lowers for Fox until at least 2017!

If you go to their website they have a quick video showing the lowers being handled in the factory (if you ever find it interesting)






*Source*:


----------



## digev (Mar 7, 2019)

FYI

Few years ago, when Fox was still producing MTB Forks and Shocks in _Watsonville, CA (before moving the production to Taiwan)_












> This fixture for example, holds fork lowers in place, so that they can be examined by a Coordinate Measurement Machine (CMM). As the small automated red ball slowly circles the fork lowers, it takes thousands of data points.
> These measurements are then uploaded to a computer, so engineers can inspect the critical features.














> One example of how the quality assurance team uses this machine is by pullin one in every 1,000 lower leg/bushing assemblies off the production line, to measure how cylindrical a bushing is after it is pressed in, the diameter, etc..














> This machine holds the lowers, while a series of rods install bushings. After installation, a bushing sizer runs through both bushings, which helps provide more consistent sizing, and reduces break in time.


Source: Fox Factory Tour Part 2: The Assembly Line


----------



## Rey112 (Jan 1, 2021)

Hello, 0.05mm clearance on the bushings will be OK?
With less slack, the stanchions run hard.


----------



## dragoontwo (Dec 2, 2020)

I'm having a heck of a time with my 2021 Fox 36 Float. The brake side leg went fine, but the drive side lower bushing does not want to play. If I put only one side of the csu in, it will fall under it's own weight on both sides. Together, there's quite a bit of force needed to get it to move. Trying to burnish the stiff lower bushing doesn't seem to do much. It seems to be getting tighter on the tool. It just won't free up. Any suggestions?


----------



## link1896 (Jul 13, 2007)

dragoontwo said:


> I'm having a heck of a time with my 2021 Fox 36 Float. The brake side leg went fine, but the drive side lower bushing does not want to play. If I put only one side of the csu in, it will fall under it's own weight on both sides. Together, there's quite a bit of force needed to get it to move. Trying to burnish the stiff lower bushing doesn't seem to do much. It seems to be getting tighter on the tool. It just won't free up. Any suggestions?


Each leg, one at a time drops through their respective lower bushings fine? If so, it's lower to stanchion width issue. Pull or push the lowers at the axle to find where it doesn't bind. Use threaded rod, nuts and washers to hold them at this width. Measure this with verniers. Should be dead on 110mm. Try with wheel in.


----------



## half_man_half_scab (Mar 7, 2006)

Generally, is it going to change the outcome for the better if you burnish wheel in?


----------



## JB450 (Mar 31, 2019)

half_man_half_scab said:


> Generally, is it going to change the outcome for the better if you burnish wheel in?


I don't think it will make any difference.

I did mine with the wheel on but only to allow an easy way to hold/clamp the lowers, it allowed me to sit on the tyre with the lowers between my knees. Made it heaps easier to burnish as the idea of putting the axle in the lowers and standing on it gave me the shivers.

Sent from my INE-LX2 using Tapatalk


----------



## digev (Mar 7, 2019)

dragoontwo said:


> I'm having a heck of a time with my 2021 Fox 36 Float. The brake side leg went fine, but the drive side lower bushing does not want to play. If I put only one side of the csu in, it will fall under it's own weight on both sides. Together, there's quite a bit of force needed to get it to move. Trying to burnish the stiff lower bushing doesn't seem to do much. It seems to be getting tighter on the tool. It just won't free up. Any suggestions?


They kind of always fall by themselves with 1 stanchion only, the problem arises when both stanchions are in (but it can be helpful for troubleshooting)


What tool do you use? What die diameter?
Is the axle in place or removed? Yes it's a floating axle so it shouldn't matter, but ...
can you visually check that lower bushing to see if there is anything obvious going on? Deformed, misaligned, rubbing marks or else
what happens when you slide the CSU backwards?
What do you mean by «it seems to be getting tighter on the tool»?
Do you burnish with oil?
Using a caliper can you measure the distance between the stanchions (inside to inside) at the top and at the bottom?

It shouldn't be difficult to cross check all these info and find out what the problem is ... you may end up with a warranty claim but either way this legit fork should slide properly! If you do end up replacing the lowers don't worry the tool will still be useful for the new ones, brand new forks are TIGHT


----------



## Rey112 (Jan 1, 2021)

dragoontwo said:


> I'm having a heck of a time with my 2021 Fox 36 Float. The brake side leg went fine, but the drive side lower bushing does not want to play. If I put only one side of the csu in, it will fall under it's own weight on both sides. Together, there's quite a bit of force needed to get it to move. Trying to burnish the stiff lower bushing doesn't seem to do much. It seems to be getting tighter on the tool. It just won't free up. Any suggestions?


You have non-coaxial bushings


----------



## dragoontwo (Dec 2, 2020)

digev said:


> What tool do you use? What die diameter?
> Is the axle in place or removed? Yes it's a floating axle so it shouldn't matter, but ...
> can you visually check that lower bushing to see if there is anything obvious going on? Deformed, misaligned, rubbing marks or else
> what happens when you slide the CSU backwards?
> ...


I will check measurements after I get back from this mornings road ride but he's what I do have.

Using the tool from Oliver. +0.07 mm
Axle installed, pinch bolt loose
Will check
Didn't think to try
It takes more force to turn than it did before
Using supergliss 100k
Will check


----------



## digev (Mar 7, 2019)

dragoontwo said:


> ...
> It takes more force to turn than it did
> ...


That alone, is the main issue, that's weird 

Definitely try to put some light into that leg, you might see something evident


----------



## romphaia (Sep 7, 2014)

dragoontwo said:


> ...
> It takes more force to turn than it did before
> ...


Once I kind of damaged a very tight bushing trying to burnish it. the PTFE layer partially detached as I pushed forcefully the tool and formed a ridge across halfway the height of the bushing. It was an upper bushing so I was able to smooth it out with sandpaper and finish it.


----------



## digev (Mar 7, 2019)

romphaia said:


> Once I kind of damaged a very tight bushing trying to burnish it. the PTFE layer partially detached as I pushed forcefully the tool and formed a ridge across halfway the height of the bushing. It was an upper bushing so I was able to smooth it out with sandpaper and finish it.


Yep, it's definitely a possibility


----------



## dragoontwo (Dec 2, 2020)

digev said:


> That alone, is the main issue, that's weird
> 
> Definitely try to put some light into that leg, you might see something evident












It would appear that the bushing may be pulled up in the leg. Is it supposed to sit on the ledge there? It is up father in the leg than the other bushing. If so, is there a way to drive it down a bit? Matt have to wait until Tuesday and see if the lbs can push it down.


----------



## digev (Mar 7, 2019)

dragoontwo said:


> View attachment 1914021
> 
> 
> It would appear that the bushing may be pulled up in the leg. Is it supposed to sit on the ledge there? It is up father in the leg than the other bushing. If so, is there a way to drive it down a bit? Matt have to wait until Tuesday and see if the lbs can push it down.


At that point your best best would be to stop and take it to the LBS because you would need the tool used to press new bushings to move it properly and without it you risk damaging the bushing itself and even the inside of the lower. Not worth it!


----------



## dragoontwo (Dec 2, 2020)

digev said:


> At that point your best best would be to stop and take it to the LBS because you would need the tool used to press new bushings to move it properly and without it you risk damaging the bushing itself and even the inside of the lower. Not worth it!


That was what I was thinking. Is it supposed to sit against the lip though?


----------



## Rey112 (Jan 1, 2021)

[


digev said:


> At that point your best best would be to stop and take it to the LBS because you would need the tool used to press new bushings to move it properly and without it you risk damaging the bushing itself and even the inside of the lower. Not worth it!


A metal washer and threaded rod are enough.


----------



## digev (Mar 7, 2019)

dragoontwo said:


> That was what I was thinking. Is it supposed to sit against the lip though?


No idea, never opened the new generation of 36s! It would be unlikely I guess ... will try to get some shots to compare.

It's somehow a good news because now you know what's wrong with it, that's already 50% of the solution


----------



## dragoontwo (Dec 2, 2020)

digev said:


> No idea, never opened the new generation of 36s! It would be unlikely I guess ... will try to get some shots to compare.
> 
> It's somehow a good news because now you know what's wrong with it, that's already 50% of the solution


My thought was that it might sit on the lip to ensure proper bushing spacing.


----------



## digev (Mar 7, 2019)

Rey112 said:


> A metal washer and threaded rod are enough.


Sure, if you feel brave enough to do it and accept the fact that you could damage something and be ok with it, then absolutely!


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## digev (Mar 7, 2019)

dragoontwo said:


> My thought was that it might sit on the lip to ensure proper bushing spacing.


Is the other bottom bushing (from the other leg) at the same depth?


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## dragoontwo (Dec 2, 2020)

digev said:


> Is the other bottom bushing (from the other leg) at the same depth?


It would appear to be so. The burnishing head rests in the same spot at the top of each bushing. Perhaps I haven't moved it out of place after all.


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## Rey112 (Jan 1, 2021)

I have a similar problem. separately stanchions works well individually, while both are not working together.
They do not walk so lightly that they fall under their own weight, but they also do not jam.
If you make them fall under their own weight, you can feel the clearance between the lower and upper shins.

Without the wheel and axle on, the drag is greater.

When the wheel is inserted and the axle clamped, there is less resistance.


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## digev (Mar 7, 2019)

Quick Tip

If the spacing between the legs dropouts is slightly less than 110mm, don’t freak out ...

Burnished a Pike today and it was 108.4mm wide

After measuring the friction force the results were:

Static: ~ 1500g
Dynamic: ~ 1500g up to ~ 2500g near bottom out

Obviously not happy about the results and knew it could be better

But once the legs got stretched a little to fit the 110mm DT350 hub, the results changed to the following

Static: ~ 300g
Dynamic: ~ 300g all the way to bottom out


----------



## minimusprime (May 26, 2009)

digev said:


> Quick Tip
> 
> If the spacing between the legs dropouts is slightly less than 110mm, don't freak out ...
> 
> ...


This seems to be pretty standard on RS products. My zeb does the same and I reached out to RS to confirm it was normal. It was implied that this is how they deal with the potential of a hub width that is less then 110mm and it is working as intended.


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## digev (Mar 7, 2019)

minimusprime said:


> This seems to be pretty standard on RS products. My zeb does the same and I reached out to RS to confirm it was normal. It was implied that this is how they deal with the potential of a hub width that is less then 110mm and it is working as intended.


Nice one! Thanks for confirming


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## Rey112 (Jan 1, 2021)

Or so. Feel a minimal slack.?


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## digev (Mar 7, 2019)

Rey112 said:


> Or so. Feel a minimal slack.?


It's normal to have a bit of play with the stanchions in the top bushings only but it should be minimal when the stanchions are in the bottom ones as well! They have to slide after all so you need a bit of clearance (it can't be felt when riding)


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## Rey112 (Jan 1, 2021)

Do longer top bushings provide better support and less wear due to less surface pressure?


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## digev (Mar 7, 2019)

Help needed!!!

Hey guys, it's a bit of a long shot but Oliver @ Blueliquidlabs needs help moving machines and goods from point A to point B and it's quite heavy! If you think you can help or know someone who does please leave a comment or reach him on IG or PM!

Just so you know, he left his day job last summer to pursue his dreams of building more stuff and help out the MTB community and this thread got started thanks to him so if you can help out ... that'd be great 

He needs a trailer to move stuff around



> I'm going from las cruces to phoenix and then back to las cruces
> 
> It needs to be a very specific type. A hydraulic drop deck trailer that can hold 10,000 pounds


Cheers guys and have a great weekend 

IG: @blueliquidlabs
PM: olivermajewski


----------



## digev (Mar 7, 2019)

BEFORE


















Streamable Video


Watch this video on Streamable.




streamable.com





AFTER


















Streamable Video


Watch this video on Streamable.




streamable.com





Source: @diazsuspensiondesign


----------



## stlburner (Dec 20, 2004)

So does this mean that the Diaz folks have the tool to do this work? I'm ready for some service and if they could do this at the same time that would be amazing. 2021 36. Thanks!



digev said:


> BEFORE
> 
> 
> 
> ...


----------



## digev (Mar 7, 2019)

stlburner said:


> So does this mean that the Diaz folks have the tool to do this work? I'm ready for some service and if they could do this at the same time that would be amazing. 2021 36. Thanks!


Absolutely! Just ask them, I think they do it for free as part of the service


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## stlburner (Dec 20, 2004)

No way! Will do.



digev said:


> Absolutely! Just ask them, I think they do it for free as part of the service


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## Le Duke (Mar 23, 2009)

Part of their normal service routine. 


Sent from my iPhone using Tapatalk


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## minimusprime (May 26, 2009)

My bushing reamer just shipped from Oliver... what oil were people using again for the reaming process? I saw some posts about it a few pages back but didn't see a consensus. Is this one of those oil is oil moments and I can use motor oil or do I need to use something special.


----------



## The_Bob (Jan 16, 2018)

I've used Fox Gold to do the bushings in my forks


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## digev (Mar 7, 2019)

minimusprime said:


> My bushing reamer just shipped from Oliver... what oil were people using again for the reaming process? I saw some posts about it a few pages back but didn't see a consensus. Is this one of those oil is oil moments and I can use motor oil or do I need to use something special.


The type of oil is not overly important but if you use the same than in your lowers it will mix and you won't have to clean afterwards, keep it simple 

It's even more true if you use a damper recirculating oil between the bath and the damper such as the GRIP or the Charger Select

If it's not one of those, we get very good results with the Motorex Supergliss 68K or 100k (depending on ambiant temperature) in the lowers so if you can get some while the fork is open that's great but bath oil is another subject all together so have a look at this link if you are interested

Source: Fork Bath Oils | Shockcraft

Happy Burnishing!


----------



## digev (Mar 7, 2019)

Today you're daily dose of smoothness is provided by @airnshox_group 










Video: Streamable Video


----------



## TazMini (Jun 21, 2019)

So getting my toolset next week and going over notes… looks like best to remove the seals, correct? Lazy me wants to keep them.


Sent from my iPhone using Tapatalk


----------



## digev (Mar 7, 2019)

TazMini said:


> So getting my toolset next week and going over notes&#8230; looks like best to remove the seals, correct? Lazy me wants to keep them.


You can keep them if you want, it doesn't matter! It's just that when you remove them you can assess the friction before/after the burnishing with nothing else interfering ... but it doesn't impact the end result! Be lazy if you want HeyHey


----------



## david31 (Jun 16, 2020)

Got around to machining a tool for my Fox 40 last week, this thread has been a great info source. My fork has about 2 years of park laps and DH racing on it, it's always felt kinda sticky compared to my 36 and old Suntour Rux.

Did it out of 6061 aluminum and had no problems, definitely don't think it needs be steel. IMO Oliver's design is more expensive and bulky than it needs to be. I made mine for ~$30 in materials. I attached my drawings if anyone wants to use them. You'll need ~2ft length of 1" aluminum bar, ~2" length of 1.75" aluminum bar per head, and a 1/2-13 nut.

I started with a ~40.07mm head










I guess there was some gray schmoo still on my tool when I burnished the bushings with it, but it was interesting to see the pattern it made. It wiped off to leave clean tan ptfe










Both my upper bushings were both out of round AND had a taper. Made probably 5-6 passes on each bushing. It now feels smooth, but the uppers don't completely drop into the lowers without a little push. Seems like a static/dynamic friction kinda thing.

Before video: before
After video: after

I won't be able to ride it until the snow melts near me, but subjectively it feels a bit smoother, not a dramatic change though just bouncing in the garage. Not sure if it's completely the bushings, I replaced the 2 year old seals with SKF ones and also put in the MY'21 air spring with a larger negative chamber.

I think I will try a 40.1mm tool next time I have my fork apart---does anyone else with a Fox 40 have recommended sizes? seems like most people in this thread have trail bike forks, not sure if it's different for big bikes.


----------



## karpiel (Aug 27, 2010)

Nice work buddy 👍🏼


----------



## digev (Mar 7, 2019)

david31 said:


> Got around to machining a tool for my Fox 40 last week, this thread has been a great info source. My fork has about 2 years of park laps and DH racing on it, it's always felt kinda sticky compared to my 36 and old Suntour Rux.
> 
> Did it out of 6061 aluminum and had no problems, definitely don't think it needs be steel. IMO Oliver's design is more expensive and bulky than it needs to be. I made mine for ~$30 in materials. I attached my drawings if anyone wants to use them. You'll need ~2ft length of 1" aluminum bar, ~2" length of 1.75" aluminum bar per head, and a 1/2-13 nut.
> 
> ...


Super cool to see other riders making their own stuff ... you'll definitely feel the difference (as per your before/after videos)! Can't wait for you to get it on the tracks and report back (but mainly enjoy the benefit of what you did)

Thanks a bunch for sharing your design, you rule 

My Boxxer was still rough after 2 seasons and I burnished it just before selling the bike so didn't get the chance to test it but based on how tight it was when disassembled and how resizing made a huge difference I believe the new owner enjoyed it very much afterwards!

Recently bought another Boxxer (been used on a Kenevo for a year) that I'm prepping to fit on a trail/enduro bike (for testing purposes) and I measured the static friction to be around 4 to 5 Kg of force (can't find the dynamic friction in my notes) but I recorded the 
Debonair Boxxer (Seal head) and the results were:

Static friction: ~ 400g
Running friction: ~ 300g - 350g

Peanuts compared to the bushings 

(You would need to record the air spring piston as well and add both values for a fair comparison but you get the idea)

On dual crowns the bushings are very tall compared to single crown forks (probably to increase stiffness) and it does increase the surface area therefore friction! In my case the stanchions diameter were still the same between all the forks tested and burnished (35mm) but jumping to 40mm stanchions is again increasing the surface area ... a bit like brake manufacturers increasing the pads surface area to increase friction therefore power ... that's exactly what we don't want with our forks 

So yeah, DH forks are very good candidates when it comes to lowering frictions against those tall bushings! And they get abused at high speed with high impacts and the upper bushings are located were there is the most leverage, if they are too tight (or out of shape/misaligned) it creates a temporary «kink» ... we all know what happens next


----------



## CCS86 (Jan 6, 2020)

david31 said:


> Did it out of 6061 aluminum and had no problems, definitely don't think it needs be steel. IMO Oliver's design is more expensive and bulky than it needs to be.
> 
> I guess there was some gray schmoo still on my tool when I burnished the bushings with it


I think that grey schmoo was your tool 

If you only want to use it once or twice, aluminum is probably fine (with proper heat treat like T6). But for any kind of longevity, making the head from steel, for better abrasion resistance, is well worth it.

Sent from my Pixel 4 using Tapatalk


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## spo0n (Nov 7, 2020)

Awesome work but those drawings being in inches hurts my head...


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## david31 (Jun 16, 2020)

CCS86 said:


> I think that grey schmoo was your tool
> 
> 
> 
> ...


I think I will need to just do the testing. I'll make the 40.1 and 40.13 out of steel in the same way and see if it leaves the grey stuff too. If it still does, then I need to clean things better 😁. Will report back once I make them.

For reference here's a picture after I wiped it out and popped the foam ring in










I really hate having to keep plain steel stuff oiled.... probably see if I can get some 17-4PH, my friends that work in machine shops say it's the sh!t.



spo0n said:


> Awesome work but those drawings being in inches hurts my head...


My school's lathes only have inch dials/no DRO and I only have inch mics... gotta run what I brung 😬 little bit of freedom units never hurt anyone 🦅🦅


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## half_man_half_scab (Mar 7, 2006)

I asked a suspension inclined mechanic buddy the “can you overdo the burnishing?” question. His response was that it was similar to drilling a hole. If your angle of attack is slightly oblique relative to the axis along the length of the lowers you could introduce bushing slop, even if the die is well sized. He’s a pretty conservative dude, but it’s interesting food for thought given that my tool is en route and sourcing new lowers for the Zeb may be no small challenge during covid. I think my approach will be to go little by little with each pass


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## digev (Mar 7, 2019)

half_man_half_scab said:


> I asked a suspension inclined mechanic buddy the "can you overdo the burnishing?" question. His response was that it was similar to drilling a hole. If your angle of attack is slightly oblique relative to the axis along the length of the lowers you could introduce bushing slop, even if the die is well sized. He's a pretty conservative dude, but it's interesting food for thought given that my tool is en route and sourcing new lowers for the Zeb may be no small challenge during covid. I think my approach will be to go little by little with each pass


You'll be absolutely fine, no worries!

Keep everything lubed while doing it and if you want to use the .1mm die, start with the 0.7mm first before using it (to stress the bushing gradually and prevent damaging the PTFE coating)

IME it's almost impossible to burnish with an angle by hand, it's so tight the only way to get the tool down is to be aligned otherwise it just doesn't go through ... so don't worry


----------



## Energ8t (Sep 10, 2013)

half_man_half_scab said:


> I asked a suspension inclined mechanic buddy the "can you overdo the burnishing?" question. His response was that it was similar to drilling a hole. If your angle of attack is slightly oblique relative to the axis along the length of the lowers you could introduce bushing slop, even if the die is well sized. He's a pretty conservative dude, but it's interesting food for thought given that my tool is en route and sourcing new lowers for the Zeb may be no small challenge during covid. I think my approach will be to go little by little with each pass


This is exactly what I was thinking would be a potential issue to be aware of.

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## Energ8t (Sep 10, 2013)

digev said:


> You'll be absolutely fine, no worries!
> 
> Keep everything lubed while doing it and if you want to use the .1mm die, start with the 0.7mm first before using it (to stress the bushing gradually and prevent damaging the PTFE coating)
> 
> IME it's almost impossible to burnish with an angle by hand, it's so tight the only way to get the tool down is to be aligned otherwise it just doesn't go through ... so don't worry


Ahh, that's good to know. Almost like hand threading... once it's going, it pretty much stays straight.

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## minimusprime (May 26, 2009)

digev said:


> You'll be absolutely fine, no worries!
> 
> Keep everything lubed while doing it and if you want to use the .1mm die, start with the 0.7mm first before using it (to stress the bushing gradually and prevent damaging the PTFE coating)
> 
> IME it's almost impossible to burnish with an angle by hand, it's so tight the only way to get the tool down is to be aligned otherwise it just doesn't go through ... so don't worry


For what it's worth, Oliver isn't shipping these out with two heads any more. You go straight to the .1mm die. Not sure if that impacts this thought process.


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## digev (Mar 7, 2019)

minimusprime said:


> For what it's worth, Oliver isn't shipping these out with two heads any more. You go straight to the .1mm die. Not sure if that impacts this thought process.


Thanks for the info, I just asked Oliver to confirm whether or not he's now shipping a +.1mm or (previous) +.07mm die with new orders. The tool always came with one die only, you could of course purchase additional ones at the same time!

If I mentioned to use the +.07mm first it's because:

A) - It's already super tight to turn in some forks/bushings and I can't imagine increasing the force needed to feed the tool and twist (hence the lub) without risking to damage the PTFE surface (but it's just a gut feeling)
B) - on the saint-gobain website they state the following



> Sizing should take place in maximum steps of 0.06 mm to prevent damage to the bearing surface


Amongst other good info

Source: https://www.bearings.saint-gobain.com/sites/imdf.bearings.com/files/norglide-bearings-brochure_0.pdf

Page 22: Sizing > Design of sizing pins

I should receive a +0.10mm die within the next few days so I'll definitely try it first to check if it's doable or risky and will share the outcome/findings


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## watermonkey (Jun 21, 2011)

I'm wondering how many sockets out there are already manufactured to the OD required to burnish your 36, 35, 34 mm bushings?


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## mike156 (Jul 10, 2017)

Sockets machined to about +/-0.02mm tolerances...

Probably zero.

Not to mention all the engraving and grooving on them.


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## watermonkey (Jun 21, 2011)

mike156 said:


> Not to mention all the engraving and grooving on them.


Speed grooves.


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## CCS86 (Jan 6, 2020)

mike156 said:


> Sockets machined to about +/-0.02mm tolerances...
> 
> Probably zero.
> 
> Not to mention all the engraving and grooving on them.


Not to mention poor cylindricity.

Sent from my Pixel 4 using Tapatalk


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## digev (Mar 7, 2019)

minimusprime said:


> For what it's worth, Oliver isn't shipping these out with two heads any more. You go straight to the .1mm die. Not sure if that impacts this thought process.


Got a reply from Oliver about that



> ... I'm still shipping 0.07 like always. There are only 2 exceptions. One is if someone specifically requests +0.1. The other case is for insanely tight forks like the MRP ribbon that have a lot of push-back from the teflon. But in those cases I always recommend going to 0.07 first because the 0.1 would be almost impossible to push in





> A lot of stanchions nowadays measure undersized. For instance the fox 36 has always measured 35.97mm since the beginning so in that sense I guess the +0.07 is technically 0.1mm bigger than the stanchion size.


I hope it clears up the confusion!


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## TazMini (Jun 21, 2019)

Maybe I missed something in the instructions, but went to burnish my new Zeb with a 38mm tool setup from Oliver. Can't seem to clear the top bushing completely. The first 70% of the process proceeded as expected (some resistance but constant pressure and turning has the tool slowly proceeding) but seem to hit a dead stop as pictured. Thoughts?

















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## half_man_half_scab (Mar 7, 2006)

Is the footnut hole plugged and it's inadvertently creating an air spring?


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## digev (Mar 7, 2019)

TazMini said:


> Maybe I missed something in the instructions, but went to burnish my new Zeb with a 38mm tool setup from Oliver. Can't seem to clear the top bushing completely. The first 70% of the process proceeded as expected (some resistance but constant pressure and turning has the tool slowly proceeding) but seem to hit a dead stop as pictured. Thoughts?


Really weird! Same thing on both sides? You lubed the tool and the bushings?
You're pushing on the tool while twisting right?


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## TazMini (Jun 21, 2019)

Footnut/bolt holes are open. Installed a spare front wheel too. I was putting a damn solid effort behind it while twisting. Going to try my Pike next, but that fork has a few rides on it.


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## half_man_half_scab (Mar 7, 2006)

I just got the tool size for a Zeb from Oliver myself today. It went in fine, pretty smooth operation. I used WPL fork boost on the die, and it went in easy. My fork has 9 months on it, so it might have been pretty well broken in already. I remember that there was kind of a brutal break in period on mine that lasted the first dozen rides or so. 

There was a noticeable difference with each pass of the die, however. Off the uppers I didn't notice much resistance from the lower bushings, but when I mated the lowers to the uppers it seemed to encounter some friction on the lower bushings. I ended up doing 4 passes on the upper bushings and 7 on the lower bushing.

Going for the test ride.


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## digev (Mar 7, 2019)

Looks like the Ibis NZ team is going to have a smooth season 










credits: @dvo_newzealand


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## digev (Mar 7, 2019)

TazMini said:


> Footnut/bolt holes are open. Installed a spare front wheel too. I was putting a damn solid effort behind it while twisting. Going to try my Pike next, but that fork has a few rides on it.


So you managed to do it?


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## TazMini (Jun 21, 2019)

digev said:


> So you managed to do it?


My year old SID and PIKE went as expected. Maybe 15mins per leg to hit it a few times. The 2 new forks are still giving me fits. Emailing back and forth with Oliver on suggestions for those new forks.

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## digev (Mar 7, 2019)

TazMini said:


> My year old SID and PIKE went as expected. Maybe 15mins per leg to hit it a few times. The 2 new forks are still giving me fits. Emailing back and forth with Oliver on suggestions for those new forks.
> 
> Sent from my iPhone using Tapatalk


Hmm interesting ... keep us posted please I'm curious about what could be the problem


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## digev (Mar 7, 2019)

half_man_half_scab said:


> I just got the tool size for a Zeb from Oliver myself today. It went in fine, pretty smooth operation. I used WPL fork boost on the die, and it went in easy. My fork has 9 months on it, so it might have been pretty well broken in already. I remember that there was kind of a brutal break in period on mine that lasted the first dozen rides or so.
> 
> There was a noticeable difference with each pass of the die, however. Off the uppers I didn't notice much resistance from the lower bushings, but when I mated the lowers to the uppers it seemed to encounter some friction on the lower bushings. I ended up doing 4 passes on the upper bushings and 7 on the lower bushing.
> 
> Going for the test ride.


What about that test ride?


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## TazMini (Jun 21, 2019)

Got to test ride the burnished 2020 SID Ultimate. Was a fairly harsh fork, but I just assumed thats how it was supposed to be since it was an XC fork. After the burnishing… smooth as churned butter. Had to add 10psi back in to get sag right. Part of me wants to share this with others and offer to work on their forks for a fee, another wants to keep it a secret lol.


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## digev (Mar 7, 2019)

TazMini said:


> Got to test ride the burnished 2020 SID Ultimate. Was a fairly harsh fork, but I just assumed thats how it was supposed to be since it was an XC fork. After the burnishing&#8230; smooth as churned butter. Had to add 10psi back in to get sag right. Part of me wants to share this with others and offer to work on their forks for a fee, another wants to keep it a secret lol.
> 
> Sent from my iPhone using Tapatalk


 don't be that man, share the love!!

Now you know the the truth about friction


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## Energ8t (Sep 10, 2013)

digev said:


> What about that test ride?


Yes, I'm curious about the ride report.

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## mak_kioy (Aug 26, 2008)

Today I did the lower leg service on a Lyrik 2019 model and on an DVO Onyx. Both of them didn't suffer from stiction on lower leg bearings. They where sliding by their weight. Just to let people know that not every fork needs this. 

(i was curious about friction on both forks and did try it, to see how they were, inspired from this topic)


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## digev (Mar 7, 2019)

mak_kioy said:


> Today I did the lower leg service on a Lyrik 2019 model and on an DVO Onyx. Both of them didn't suffer from stiction on lower leg bearings. They where sliding by their weight. Just to let people know that not every fork needs this.
> 
> (i was curious about friction on both forks and did try it, to see how they were, inspired from this topic)


A video would have been great because the odds of having 2 different forks sharing the same level of friction are very very slim  Checking first is the key decision factor, it's been stated several times since the beginning and is kind of obvious ... that's exactly what you did


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## B. Rock (Mar 9, 2011)

Has anyone done this on a Ribbon yet? I see on their website they have a special tool just to remove the damper. Lots of folks with stiction complaints on them too.


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## digev (Mar 7, 2019)

B. Rock said:


> Has anyone done this on a Ribbon yet? I see on their website they have a special tool just to remove the damper. Lots of folks with stiction complaints on them too.


Not personally, but Oliver (Who makes the burnishing tool) said the MRP Ribbon has insanely tight bushings!


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## half_man_half_scab (Mar 7, 2006)

[/QUOTE]


Energ8t said:


> Yes, I'm curious about the ride report.


I didn't notice a dramatic difference, but the fork has well over 200 hours on it, so I suspect it's already fairly broken in. Alternatively, I may have been too conservative with the number of passes, and will check again when replacing the seal. I'm grateful to have the tool on hand, I'll probably grab a few more dies later, as I can see it being very useful for new forks.


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## Nikola777 (Jun 4, 2017)

I bought used Lyrik with Push ACS3 spring kit instaled.
Initional travel is going ok . But when I compress fork with, let say, 60kg. And in that position i can add +-15kg and fork will not move. It is sticky when aplayed biger forces.
I made a tool for bushings. And used it on my Lyrik. Without seals there is no friction at all. Lowers falling by its own weight. When i mount the wheel there is no difference. Also good.
I assembled the whole fork but there was no improvement. :-(
If i remove spring out and try without it there is no that sticky issue.
If i mount lowers only on left stanchion and mount spring and then try to compress this stickion is reduced by 80%. (so, it is not spring kit wich do this friction)
I noticed (also without spring instaled) when I torsionally compress the fork (when the bike is tilted at an angle and I only add compression force on one side of the handlebar) then the compression friction increases quite a bit.
I used Rockshox 0W-30 oil for lowers. And RockShox Dynamic Seal Grease (PTFE) green one for seeals. In last month i disassembled the fork atleast 5 times trying to improve something without any sucess. Last thing what i done is that i used RockShox Dynamic Seal Grease to grese all lowers, bushings and upers with it. And i assembled fork that way. 
Stiction is reduced by 50% but fork now behave like it is -20C outside. 
Last thing that i notice is that stanchions is not smooth like glass . When i try with finger nail to go up and down on stanchions it have a fealing like you rubbing on screw with tiny micro thread. (dont know how to discribe that feeling) 
Can some of you do that test also? With hard compresion. Does it stick like my. And on stanchions with finger nail.
Will Motorex SuperGliss 100k improve something?
Can anyone give some solution?
Thank you.


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## AcidLegs (Aug 9, 2017)

B. Rock said:


> Has anyone done this on a Ribbon yet? I see on their website they have a special tool just to remove the damper. Lots of folks with stiction complaints on them too.


I did. It helped a lot, the bushings were super tight. I didn't get along well with the damper, though, so I replaced it with a DVO Diamond (the Ribbon is now on my daughter's bike, and has been re-tuned for her weight).


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## Nikola777 (Jun 4, 2017)

Nikola777 said:


> I bought used Lyrik with Push ACS3 spring kit instaled.
> Initional travel is going ok . But when I compress fork with, let say, 60kg. And in that position i can add +-15kg and fork will not move. It is sticky when aplayed biger forces.
> I made a tool for bushings. And used it on my Lyrik. Without seals there is no friction at all. Lowers falling by its own weight. When i mount the wheel there is no difference. Also good.
> I assembled the whole fork but there was no improvement. :-(
> ...


Today i removed lowers and polished stanchions with
Cerium Oxide (Powder for polishing glass)
I spent 4 hours on that procedure. Now the stanchions are as smooth as glass.
Friction has reduced at least for 50% and i am prety much pleased with results.


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## evernorth (Apr 13, 2020)

Nikola777 said:


> Today i removed lowers and polished stanchions with
> Cerium Oxide (Powder for polishing glass)
> I spent 4 hours on that procedure. Now the stanchions are as smooth as glass.
> Friction has reduced at least for 50% and i am prety much pleased with results.


Mhm does that affect their ability to hold on some oil? For bushing lubrication?

I might be offline here but my thought is, if you polish the finish, oil does not have a chance to stick to it and therefore the bushing lubrication might suffer, which in long term might shorten their lifespan quite a bit. Open for discussion though!

Cheers

Gesendet von meinem Pixel 5 mit Tapatalk


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## Nikola777 (Jun 4, 2017)

evernorth said:


> Mhm does that affect their ability to hold on some oil? For bushing lubrication?
> 
> I might be offline here but my thought is, if you polish the finish, oil does not have a chance to stick to it and therefore the bushing lubrication might suffer, which in long term might shorten their lifespan quite a bit. Open for discussion though!
> 
> ...


I have no idea. I didn't think in that direction.
It have sense.
But I accept a trade for smoothness.


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## x-force (Jan 20, 2021)

evernorth said:


> Mhm does that affect their ability to hold on some oil? For bushing lubrication?
> 
> I might be offline here


you are not!

people say the same thing about kashima


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## Nikola777 (Jun 4, 2017)

What did you want to say?
What people say about kashima?


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## x-force (Jan 20, 2021)

Ole said:


> I have also heard that Kashima is not so good at bringing lube oil up past the bushings, oil doesn't adhere to it so well. Any thoughts on this?





ghostbiker said:


> Yes, Kashima is not good, it´s too smooth with pores filled in, so there is nowhere for oil to stick. But it´s low friction if you like running your forks dry lol.





digev said:


> I've had Kashima forks since they got released many years ago and the last 36 (3years ago) had the black stanchions and it made absolutely no difference whatsoever (brake away force was the same and I didn't notice any improvement in that regard)! So yeah, Kashima is probably slightly better on paper or in a lab but there's probably many things to fix/improve before getting the benefit of a very slight decrease in friction compared to say ... tight bushings, LOL
> 
> BTW Kashima coating is impregnated with MoS2 (Super low friction coefficient: 0.06) but a good old rub will generate a huge amount of static and dynamic friction, way way wayyyy more than any fancy surface treatment can help with!


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## Nikola777 (Jun 4, 2017)

Thank You. 👍


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## TazMini (Jun 21, 2019)

Put 5 hours on the new ZEB fork and pulled lowers again and burnishing the bushings went easy-peezy. So brand new forks are a PITA. Go ride the fork in, and then burnish lol.


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## half_man_half_scab (Mar 7, 2006)

TazMini said:


> Put 5 hours on the new ZEB fork and pulled lowers again and burnishing the bushings went easy-peezy. So brand new forks are a PITA. Go ride the fork in, and then burnish lol.


That jives with my experience of the break-in sucking on this fork.


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## TazMini (Jun 21, 2019)

half_man_half_scab said:


> That jives with my experience of the break-in sucking on this fork.


Right. After riding my burnished SID and PIKE, trying to ride the ZEB was terrible. "Is this thing even working!!!"
Can't go back to 'normal' forks.


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## digev (Mar 7, 2019)

TazMini said:


> Put 5 hours on the new ZEB fork and pulled lowers again and burnishing the bushings went easy-peezy. So brand new forks are a PITA. Go ride the fork in, and then burnish lol.


That's good to know, thanks for sharing your issue/experience ... and the solution that goes with it 

They were indeed mega tight 

Have a smooth ride


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## digev (Mar 7, 2019)

When you know, you know 



















Credits: @suspensionworksnz


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## karpiel (Aug 27, 2010)

I received mine a few days ago with 32,34,35,26,27,28 and 40mm dies, I'm going to burnish my 34 and 36 once a vice mounted 15mm through axel clamp arives in the post 👍🏼


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## karpiel (Aug 27, 2010)

digev said:


> When you know, you know
> 
> 
> 
> ...


Dude, are you not using the plastic guides ?


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## Rick Draper (Dec 1, 2009)

digev said:


> When you know, you know
> 
> 
> 
> ...


What I find amusing is all these places that proclaim to be "suspension service centres" but they didn't own a bushing sizing tool or certainly heads for various different sizes of stanchion until Oliver at BLL started making them.


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## TazMini (Jun 21, 2019)

Burnished 6 forks today and gave myself a blister lol









Sent from my iPhone using Tapatalk


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## digev (Mar 7, 2019)

Rick Draper said:


> What I find amusing is all these places that proclaim to be "suspension service centres" but they didn't own a bushing sizing tool or certainly heads for various different sizes of stanchion until Oliver at BLL started making them.


suspensionsworknz has only been opened since November last year (2020)  But yeah I know what you mean! Well, better late than never I guess


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## digev (Mar 7, 2019)

karpiel said:


> I received mine a few days ago with 32,34,35,26,27,28 and 40mm dies, I'm going to burnish my 34 and 36 once a vice mounted 15mm through axel clamp arives in the post


You could have done it without but that way you'll have the pleasure to test both  From where did you find it please?

I'm waiting for stuff as well, the install/removal tool + 35.1mm die ... to test the ND Tuned bushings



karpiel said:


> Dude, are you not using the plastic guides ?


The only guides I've seen were 3D printed and used by CCS86 when he decided to make his own tool (in a rather short and impressive turnaround)



TazMini said:


> Burnished 6 forks today and gave myself a blister lol


Hahaha burnishing like a maniac already ... be careful it's addictive! it's also a good way to warm you up when the garage is a bit cold


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## karpiel (Aug 27, 2010)

digev said:


> You could have done it without but that way you'll have the pleasure to test both  From where did you find it please?
> 
> I'm waiting for stuff as well, the install/removal tool + 35.1mm die ... to test the ND Tuned bushings
> 
> ...


The axel clamp is from Andreani, my guides came with the tool from Oliver.


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## digev (Mar 7, 2019)

karpiel said:


> The axel clamp is from Andreani, my guides came with the tool from Oliver.


Thanks 

No guides for me, not that I feel the need for some but it's good to have (did you ask for it?)


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## karpiel (Aug 27, 2010)

digev said:


> Thanks
> 
> No guides for me, not that I feel the need for some but it's good to have (did you ask for it?)


Yes, I asked for them, I think they are needed to help straight insertion of the tool, afterall you want the bushes completely concentric to the stantions, and it stops the metal locking collar scratching the seat of the wiper seal.


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## digev (Mar 7, 2019)

karpiel said:


> Yes, I asked for them


They're not _needed_ but if you have them, sure ... use them!

The fit between the tool and the bushing is so tight, I don't think you can put it at an angle _by hand_

And for the seals ... you only feed the tool a few times with lots of oil on it and all that at very very low speed so again it's probably not enough to damage the surface ... definitely way less than dirty stanchions full of debris going up and down thousands of times during a muddy ride for example


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## digev (Mar 7, 2019)

Here's a quick slow-mo video of a 2020 Boxxer on a scale in order to roughly measure the static friction (no spring, no damper, no seals)









Streamable Video


Watch this video on Streamable.




streamable.com





That fork has been ridden by a ~ 100kg rider on a Kenevo for about 6 months

Crap quality and a bit too dark but that's not what matters 

Edit: bear in mind that this test gives a a value for when it's pushed at approximately 45° ... you can expect higher values when the head angle is around 64/65 (ich)


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## karpiel (Aug 27, 2010)

digev said:


> Here's a quick slow-mo video of a 2020 Boxxer on a scale in order to roughly measure the static friction (no spring, no damper, no seals)
> 
> 
> 
> ...


What unit of measurement is the scale in as its not very clear, I'm assuming KG ?


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## digev (Mar 7, 2019)

karpiel said:


> What unit of measurement is the scale in as its not very clear, I'm assuming KG ?


Yes Kg (so just over 4Kg of friction force)


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## digev (Mar 7, 2019)

The good thing about custom tools!










@dvo_newzealand


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## jayblack (Dec 29, 2009)

My local machine shop made one for me, can't wait to try it on my Zeb. Will keep you updated.


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## digev (Mar 7, 2019)

jayblack said:


> My local machine shop made one for me, can't wait to try it on my Zeb. Will keep you updated.


Hey Hey ... sweet


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## spo0n (Nov 7, 2020)

I am no expert, but looks like a kinda steep chamfer with a sharp edge


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## jayblack (Dec 29, 2009)

There is no sharp edge, maybe it is from the picture. If I have a chance tonight I'll take another photo.


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## Brian412 (Jul 27, 2008)

I jumped on this bandwagon and got a 35.07 tool from Oliver to work the bushings on my 140 2020 Pike Ultimate on my Ripley V4. Small bump sensitivity never felt very good. The stiction was so bad it was hard to set sag correctly. I took out the air spring and damper, and with only the seals in place, it took 10-11lbs to get the lowers to move. 

I ran the tool through the upper and lower bushings about 4 times each....so 8 passes past each bushing. The upper and lower bushing had about the same amount of resistance. Following the burnishing, it took about 4-5lbs to move the lowers. 

On the trail....so much smoother! Sensitivity is greatly improved and now almost matches the DBairIL on the rear. Prior to the burnishing I always had 15-20mm of travel left on the fork after a ride on my local trail. Now I'm using all but 5mm of travel with an occasional bottom out. Overall, I'm definitely pleased with the results.


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## digev (Mar 7, 2019)

Brian412 said:


> I took out the air spring and damper, and with only the seals in place, it took 10-11lbs to get the lowers to move.
> 
> ...
> 
> Following the burnishing, it took about 4-5lbs to move the lowers.


Keep going!!! 2.5kg is better than 5kg but don't settle for it ... you are on the right track and can reduce the frictions even more ... less than 1Kg is achievable and you should aim for that! Keep burnishing until the uppers or lowers fall into each other with no other help than just gravity ... at that point you'll know you are under 1Kg of friction! You have the tool, you have the knowledge and how-to and now you've experienced how less frictions translates to a better ride quality ... go all the way 

Thanks for posting your feedback, it's always a pleasure to read, and knowing other riders are getting the full benefit of a well tuned chassis is so worth it

Fun fact of the day

When testing for bushings roundness/circularity, @takumisuspensions (suspension center and Vorsprung Elite partner over in Peru) discovered than on average they are between 0.03 to 0.05mm out of shape (oval shaped)! First time I see someone use a bore gauge AND publish the results so kudos to him


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## x-force (Jan 20, 2021)

digev said:


> they are between 0.03 to 0.05mm out of shape (oval shaped)!


why not round shaped?
how do you deduce that?

i guess you have to turn the bore gauge and read it continually? but did he do that?


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## Rey112 (Jan 1, 2021)

Because the sleeves in the lags are thin-walled and are usually put on a strong push, this alone causes them to ovulate and take the shape of the lag's imperfections.


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## x-force (Jan 20, 2021)

Rey112 said:


> Because the sleeves in the lags are thin-walled and are usually put on a strong push, this alone causes them to ovulate and take the shape of the lag's imperfections.


that would mean* every *fork needs the bushings shaped, but several guys in this thread said their fork works fine without.


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## CCS86 (Jan 6, 2020)

x-force said:


> that would mean* every *fork needs the bushings shaped, but several guys in this thread said their fork works fine without.


Saying your fork "works fine" doesn't mean anything.

Every single fork has bushings with less than perfect cylindricity and in almost every case it would be improved by burnishing.

Sent from my Pixel 4 using Tapatalk


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## x-force (Jan 20, 2021)

CCS86 said:


> Every single fork has bushings with less than perfect cylindricity and *in almost every case* it would be improved by burnishing.





mak_kioy said:


> Today I did the lower leg service on a Lyrik 2019 model and on an DVO Onyx. Both of them didn't suffer from stiction on lower leg bearings. They where* sliding by their weight*. Just to let people know that not every fork needs this.


a real rate/proportion would be interesting nonetheless

people posting here will be mostly people who found an issue


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## JB450 (Mar 31, 2019)

x-force said:


> a real rate/proportion would be interesting nonetheless
> 
> people posting here will be mostly people who found an issue


My forks didn't slide under their own weight, but they also seemed to work totally fine on the trail (I am a heavier rider).

After burnishing they do slide under their own weight and they are much improved on the trail.

The "sliding under their own weight" is just a way to gauge a change in bushing friction when burnishing and isn't a guarantee that the fork works well on the trail.

Sent from my INE-LX2 using Tapatalk


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## karpiel (Aug 27, 2010)

I was'nt happy with the idea of standing on the axel, so here is how I do it, complete with skateboard grip tape.


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## jayblack (Dec 29, 2009)

jayblack said:


> My local machine shop made one for me, can't wait to try it on my Zeb. Will keep you updated.


My friend's fork got the special treatment before mine.
Before








Streamable Video


Watch this video on Streamable.




streamable.com




After








Streamable Video


Watch this video on Streamable.




streamable.com


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## digev (Mar 7, 2019)

karpiel said:


> View attachment 1922666
> 
> I was'nt happy with the idea of standing on the axel, so here is how I do it, complete with skateboatd grip tape.


Sweet set up 



jayblack said:


> My friend's fork got the special treatment before mine.
> Before
> 
> 
> ...


Nothing beats a good «Before vs After»


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## karpiel (Aug 27, 2010)

......and the drivers view.
Great tool Oliver, thank you 👍🏼


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## Brian412 (Jul 27, 2008)

digev said:


> Keep burnishing until the uppers or lowers fall into each other with no other help than just gravity ... at that point you'll know you are under 1Kg of friction!


Are you getting the uppers to fall into the lowers with just gravity with the seals in place? I did not remove the seals for the test.


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## digev (Mar 7, 2019)

Brian412 said:


> Are you getting the uppers to fall into the lowers with just gravity with the seals in place? I did not remove the seals for the test.


Good point, it's without!

Edit: but 2.5kg of static friction (with the seals) is still too much you can lower that value if you keep burnishing


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## digev (Mar 7, 2019)

Ever wondered how bushings are pressed when they are assembled at the factory? Here's how!










By the owner of DVO himself, Bryson Martin


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## Matt20001 (Jul 21, 2018)

And another super satisfied customer! 
after playing with the settings / servicing and failing to get a smooth fork ( it remained sticky and harsh at the top of the stroke), i found this thread and bought the tool from Oliver for a fox 36 performance elite with grip2 from 2019. 
we did 6 down + 6 up on each bushing. the harshness and initial stickiness when pressing the handlebar is now 100% gone. it is a different fork, mega sensitive from the top of the stroke. and all this with zero play in the bushing either.

we lubed the dye abundantly, and let the bushings cool down between passes as the heat was transferring into the lowers ( we could feel it by hand).
I am not a skilled mechanic, so this is really doable by almost anyone. Highly recommended!

Best,

Matt


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## jayblack (Dec 29, 2009)

Another happy friend. There is no before video, but the fork was quite tight on the ride side and kinda okay on the left. Now is super smooth.








Streamable Video


Watch this video on Streamable.




streamable.com


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## Preston67 (Mar 20, 2008)

Eagerly awaiting the tool from Oliver. Emailed him 6 weeks ago, said he had a 4 week backlog. No dig at Oliver, I'm sure he's doing the best he can. 

Despite a lot of experience with fabrication, I still don't really have a good contact for small machine jobs or I'd have one made locally. 
Fork is overdue for a rebuild but want to wait until I can hone it !


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## digev (Mar 7, 2019)

Preston67 said:


> Eagerly awaiting the tool from Oliver. Emailed him 6 weeks ago, said he had a 4 week backlog. No dig at Oliver, I'm sure he's doing the best he can.
> 
> Despite a lot of experience with fabrication, I still don't really have a good contact for small machine jobs or I'd have one made locally.
> Fork is overdue for a rebuild but want to wait until I can hone it !


Got my parcel from him today (35.1mm die + install/removal bushing tool) ... it took 6 weeks to arrive (since it got shipped) ... yep 

I'll post some pics tomorrow!!


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## digev (Mar 7, 2019)

jayblack said:


> Another happy friend.





Matt20001 said:


> And another super satisfied customer!


Yeahhh! Let's bring the joy back into your rides 

As usual, thanks for the feedback!


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## glano (Apr 12, 2009)

Blue Liquid Labs FTW!! ...yet another satisfied customer here!


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## SleepeRst (Nov 30, 2011)

I took a different approach here. I live in an apartment and haven't really wanted to do any dirty jobs such as servicing my fork, so I shipped my fork out to Oliver. He took care of the full rebuild and performed the burnishing in house. In the future I will more than likely purchase the burnishing tool from him, but right now I am happy with the price and quality of service he offered. So for those who want to burnish their bushings but may not want to tackle it for a variety of reasons he can perform the service for you!


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## digev (Mar 7, 2019)

@dvo_newzealand making it smooth again 









Streamable Video


Watch this video on Streamable.




streamable.com


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## Phase__ (Apr 12, 2021)

Does anyone have the burnishing tool for a Lyrik to loan in SoCal? Really interested in doing this as I suspect my bushings are pretty tight, but would love to not have to splurge on the whole tool for a one-time job? Alternatively, anyone know of shops that offer the service?


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## x-force (Jan 20, 2021)

digev said:


> Got my parcel from him today (35.1mm die + install/removal bushing tool) ... it took 6 weeks to arrive (since it got shipped) ... yep


what did you pay including tax, customs and delivery?


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## SoCal-Rider (May 25, 2009)

Phase__ said:


> Does anyone have the burnishing tool for a Lyrik to loan in SoCal? Really interested in doing this as I suspect my bushings are pretty tight, but would love to not have to splurge on the whole tool for a one-time job? Alternatively, anyone know of shops that offer the service?


You might try Fluid Focus in San Marcos. FWIW They mention "bushings sized accordingly" on their site.






Fluid Focus, LLC — Mountain Bike Suspension Services :: Full service mountain bike suspension service center located in San Diego, CA :: Mountain Bike Suspension Service + Suspension Service Mtb + Mountain Bike Suspension Fork Service + Rockshox Suspension Service + Fox Suspension Service + Mtb Suspension Tuning + Custom Mtb Suspension Tuning + Mtb Suspension Service + Mountain Bike Suspension Tuning Service + Mtb Shock Service


We service, repair, and tune most major brands. Fluid Focus has years of extensive suspension experience which includes factory race team duties :: Suspension Service Mtb + Mountain Bike Suspension Service + Mountain Bike Suspension Fork Service + Mtb Rear Shock Service + Rockshox Suspension Service




www.fluid-focus.com


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## onzadog (Jan 6, 2008)

I've used this tool on a few forks now and it's made a massive difference. However, they've all been forks that were due a service and needed a seal change.

I've now got a couple of new forks I want to do. Do I...
1. Suck it up and replace the seals anyway?
2. Does anyone know how to remove seals without damage?
3. If I leave the seals in, any tips on knowing when I've done enough?

Thanks.


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## digev (Mar 7, 2019)

onzadog said:


> I've used this tool on a few forks now and it's made a massive difference. However, they've all been forks that were due a service and needed a seal change.
> 
> I've now got a couple of new forks I want to do. Do I...
> 1. Suck it up and replace the seals anyway?
> ...


Don't worry, you don't need to replace the wiper seals ... it just makes your life easier to gage the difference (before/after) but it's not required to do the job

Pretty sure you could re-use them after using a big open wrench to pop them out because the base is where you apply the force and it's reinforced but I usually throw them away. You could try on a test fork where you plan to change them anyway to see if it makes a difference 

Without the seals it's easy(ier) to spot if you've done enough as the uppers glide into the lowers under their own weight but if you measure the friction force before and after (even with the seals on) it should give you a pretty good idea of the improvement ... average recorded values on my side are about 700g or less without the seals and around 1Kg or less with the seals on!

Push the fork down against a bathroom scale and slow-mo record the values it gives. Then do it again after burnishing to measure the difference

Good luck


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## JB450 (Mar 31, 2019)

onzadog said:


> I've used this tool on a few forks now and it's made a massive difference. However, they've all been forks that were due a service and needed a seal change.
> 
> I've now got a couple of new forks I want to do. Do I...
> 1. Suck it up and replace the seals anyway?
> ...


I did a lower lube refresh the other day (just lube, seals were newly installed a month ago) and burnished the bushes again, just because.

No issues.

Sent from my INE-LX2 using Tapatalk


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## Floor Tom (Aug 2, 2012)

Took my lyrik apart to burnish the bushings and found that they were actually very good from the factory, I ran the tool through both sides anyway but I am not expecting much, the lowers would move under their own weight already. Might have made a little difference towards the end of the stroke but not much.
Need to strip my boxxer down next and see how tight those bushings are.


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## onzadog (Jan 6, 2008)

Thanks. Good to have some numbers to work to. Previously, with the seals out, I've just gone until the CSU drop in under its own weight. Possibly doing too little rather than too much. Do you take your measurements with the fork chassis the right way up, or inverted?


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## onzadog (Jan 6, 2008)

I've stripped the forks down, a low mileage revelation from my wife's bike. Seals are still in but I've removed the garter springs. Lowers have been drained but not wiped and foam rings removed.

With the steerer on the kitchen scales I'm pressing on the dropouts and the scales have maxed out at 5kg.

It's tool time!


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## Preston67 (Mar 20, 2008)

It often seems unnecessary to me to replace the wipers unless they get damaged during removal. I haven't had a wiper leak or weep in years and years and as long as you clean them I don't see that they would add anymore drag over time. Next time I'm going to see if I can just get a bag of replacement foam rimgs, and start re-using the wipers. No need to pay $30 every time you do a lower service.


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## onzadog (Jan 6, 2008)

Well, it took a while to sort the wife's Revelation fork. When from over 5kg to get them moving to just under 2.5kg with the seals still in.

I think the legs were quite different in size. Swapping stanchions from one side to the other made a noticeable difference. I eventually got to a point where each stanchion on its own would slide in under its own weight.

No idea how many passes it took but by the time I was done, there was a lot less resistance on the tool. Interestingly, the heat generated made quite a difference to the fit. The stanchion would slide in under its own weight just after honing but would then stick once the lowers had cooled. 

If it helps anyone else with theirs, I will say this. Leaving the seals in is not a problem. Let the lowers cool to get a true measure and if you take the garter spring off the seal, the stanchions can fall under gravity when inserted one at a time.

I'm also, no longer worried about going too far in terms of creating clearance.


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## romphaia (Sep 7, 2014)

It's definitely better to have too much clearance than too little.Thermal expansion and elasticity of the ptfe coating all concur to decrease it.


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## 294037 (Jun 30, 2006)

Yeah the acceptable clearance for bushings is so much bigger than people think! It's pretty hard to make them too loose


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## OneTrustMan (Nov 11, 2017)

Has someone of you experienced different stanchions size on RS forks?
I have 3 RS forks, a Pike, a Lyrik and a Sektor. On all these forks the stanchions on the air side is a little bit thicker, than the damping side.
Is this because of the pressure inside the air spring?

Also this tool from Oliver.


digev said:


> The good thing about custom tools!
> 
> 
> 
> ...








Blue Liquid Labs | An Oliver Majewski Project







blueliquidlabs.com




I can't find it on his website.
Does he still make it? And how much is it with shipping to europe?


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## digev (Mar 7, 2019)

OneTrustMan said:


> Has someone of you experienced different stanchions size on RS forks?
> I have 3 RS forks, a Pike, a Lyrik and a Sektor. On all these forks the stanchions on the air side is a little bit thicker, than the damping side.
> Is this because of the pressure inside the air spring?
> 
> ...


As mentioned before you can have all sorts of variations everywhere but they are usually pretty random

Good news is ... it doesn't matter where they are as long as you give enough room to the stanchions to move freely 

If you want to get a tool from Oliver it's best to send him a private message via Instagram @blueliquidlabs or ping him an email @ livamysta26 [at] hotmail.com

Shipping to EU was 30 USD and the tool + 1 die is 140 USD

Hope this help!


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## OneTrustMan (Nov 11, 2017)

digev said:


> As mentioned before you can have all sorts of variations everywhere but they are usually pretty random
> 
> Good news is ... it doesn't matter where they are as long as you give enough room to the stanchions to move freely
> 
> ...


Thank you. 
I will send him a message. 
This tool looks very well done, and I love good tools.


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## CrozCountry (Mar 18, 2011)

Is there any suspension shop that is doing it in the US? Ideally in norcal?


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## Le Duke (Mar 23, 2009)

CrozCountry said:


> Is there any suspension shop that is doing it in the US? Ideally in norcal?


Diaz does it as part of any tuning process you purchase. But they are in Durango.


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## soulshaker (Sep 23, 2013)

Got my tool from BlueLiquid this week and am doing the first Pike this weekend. See how it goes!


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## FactoryMatt (Apr 25, 2018)

CrozCountry said:


> Is there any suspension shop that is doing it in the US? Ideally in norcal?


Pm me. Im in norcal.


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## lawson (Apr 3, 2007)

Does anybody have the 35.1 size in the UK by any chance please? 

Sent from my CLT-L09 using Tapatalk


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## onzadog (Jan 6, 2008)

UK is a big enough place, where abouts? I've got the 34 and the 35.


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## lawson (Apr 3, 2007)

I'm in Cornwall.

Sent from my CLT-L09 using Tapatalk


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## onzadog (Jan 6, 2008)

Ah, only 350 miles from me then!


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## lawson (Apr 3, 2007)

onzadog said:


> Ah, only 350 miles from me then!


Where are you?

Sent from my CLT-L09 using Tapatalk


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## lawson (Apr 3, 2007)

onzadog said:


> Ah, only 350 miles from me then!


Sent you a pm

Sent from my CLT-L09 using Tapatalk


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## rstark18 (Apr 10, 2006)

soulshaker said:


> Got my tool from BlueLiquid this week and am doing the first Pike this weekend. See how it goes!


When did you order yours? I ordered about a month ago. Hopefully I'll get it soon.


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## Jre (Aug 21, 2018)

My 2018 Pike has been quite sticky for the last two years. I remember it being a nice and plush fork when it was new, hence tight bushings suddenly causing the stiction would be very unlikely. Not going to exclude that possibility though as I don't know how the fork materials will act when they wear.

Better guess would be that the bushings are worn out slightly, creating stiction when the fork is being bent by the rider weight. When I apply front brake and push the bike forward during the sticky part of travel, the fork quickly releases and goes through, which might suggest exactly this issue. All logical so far but the weird thing is that I can't feel any excess play when rocking the fork back and forth and I know what a loose fork feels like. It might make sense if the fork is just slightly too loose to work properly but all this thinking just feels pointless as there is no clean sign about any issue but the symptom itself.

Servicing: Found out that if I do a lower leg service like after every fourth ride it will stay nice and smooth (of course since the fluids are spread everywhere), but that is definitely not how it should be. Also original Rockshox fluids all the way and damper cartridge is not the issue either, I took it out and tried without it. Replaced the fork seals as well and nothing changed. Storing the bike upside down has been suggested to help but in my opinion not fixing the actual problem.

Is this just how Rockshox forks are with the miserable amount of oil in the lowers, one to two years of light trail riding and they start sticking? I have ordered a new pair of lowers (got half the price thankfully) to exclude any reason from the bushing play to bent lowers, so let's hope this will solve the issue. Maybe I just have a bad copy that should have been fixed under warranty. However, would be nice to know if people have experienced the same and if I can do something to avoid the bushing issues with the new lowers.


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## soulshaker (Sep 23, 2013)

rstark18 said:


> When did you order yours? I ordered about a month ago. Hopefully I'll get it soon.


I'd say it took a bit over a month.


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## onzadog (Jan 6, 2008)

@lawson. Not keen on the idea of posting my tool to someone else but would consider doing them for you in exchange for a donation to a local charity.


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## lawson (Apr 3, 2007)

onzadog said:


> @lawson. Not keen on the idea of posting my tool to someone else but would consider doing them for you in exchange for a donation to a local charity.


Where are you then? That's a very kind offer 

Sent from my CLT-L09 using Tapatalk


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## CrozCountry (Mar 18, 2011)

Jre said:


> My 2018 Pike has been quite sticky for the last two years. I remember it being a nice and plush fork when it was new, hence tight bushings suddenly causing the stiction would be very unlikely. Not going to exclude that possibility though as I don't know how the fork materials will act when they wear.
> 
> Better guess would be that the bushings are worn out slightly, creating stiction when the fork is being bent by the rider weight. When I apply front brake and push the bike forward during the sticky part of travel, the fork quickly releases and goes through, which might suggest exactly this issue. All logical so far but the weird thing is that I can't feel any excess play when rocking the fork back and forth and I know what a loose fork feels like. It might make sense if the fork is just slightly too loose to work properly but all this thinking just feels pointless as there is no clean sign about any issue but the symptom itself.
> 
> ...


Have you tried fox gold fluid in the lowers?


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## CrozCountry (Mar 18, 2011)

Since fox 36 grip forks are using a different lubricant in each leg of the lowers (super sticky in the air spring side and pretty thin 5W in the damper side), should the bushing clearance be different in each leg?


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## Sam Handwich (Nov 22, 2018)

Anyone have suggestions for somewhere that does this as a service? In the general, Connecticut vicinity would be a bonus, but I'm also willing to ship my fork within the US. If it matters, I have a 2019 Fox 36 with Grip 2 damper.


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## CrozCountry (Mar 18, 2011)

Jre said:


> My 2018 Pike has been quite sticky for the last two years. I remember it being a nice and plush fork when it was new, hence tight bushings suddenly causing the stiction would be very unlikely. Not going to exclude that possibility though as I don't know how the fork materials will act when they wear.
> 
> Better guess would be that the bushings are worn out slightly, creating stiction when the fork is being bent by the rider weight. When I apply front brake and push the bike forward during the sticky part of travel, the fork quickly releases and goes through, which might suggest exactly this issue. All logical so far but the weird thing is that I can't feel any excess play when rocking the fork back and forth and I know what a loose fork feels like. It might make sense if the fork is just slightly too loose to work properly but all this thinking just feels pointless as there is no clean sign about any issue but the symptom itself.
> 
> ...


Did you rebuild the air spring? It's not that complicated to do, extra 10 minutes if you do lowers service.
If your fork did not come with debonair air spring, it's the best bang for your dollars of any suspension upgrade. It was $40 before the bikepocalypse.
I also use Fox Gold, which technically is not recommended, but I prefer it to rockshox fluids.
There are also multiple versions of dust wipers for those forks, some lower friction that others. At least there were when I had a pike.


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## Den Capra (Jul 7, 2021)

Hi everyone this is my first post. 
Im v excited to read this thread as sticky forks have been a real pain for me in the last few years. I have a 2019 Lyrik which has been harsh and bouncy from day 1. I’ve played with pressures and rebounds but no improvement. I was on point of sending them in for warranty claim but I was fairly sure I would get told “Ah there’s nothing wrong with them”. 
Then I sent an email to Steve at Vorsprung and he mentioned bush sizing as 1 of the possible causes of my problem. And that lead to Google search which led to here. Anyone I’ve spoken to about their Lyriks tend to say “oh well they aren’t very supple but they do give great support!”
So here’s hoping that I get a big improvement as soon as I get this tool from Liquid Labs. 
Big thanks to everyone who’s given their time and input to this thread - the knowledge and experience is priceless. 
Den


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## onzadog (Jan 6, 2008)

The wife's Revelation was terrible and needed a lot of adjustment. A big benefit was noticed afterwards. My 2021 Lyrik was about perfect from a bushing point of view. So, no real improvement for me. They still feel like they need much less low speed compression.

Currently torn between the idea of an Avalanche hybrid damper tuned for me, or a smashpot. The thinking there is that about half the stiction in a fork comes from the air spring.


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## Tobi1991 (Jul 16, 2021)

Hey guys, its my first post here.

Im currently thinking if this can be a bushing problem:

Youtube link:Fox 36 verzogen?! Oder Buchsen fehler?!

Only one stanchion slides perfectly but both at the same time result in some friction.

Its not very much force needed but testet this on my fox 34 and it runs much more freely even with both stancions in.


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## areks (Jan 30, 2016)

install your wheel, tighten axle then try again


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## Tobi1991 (Jul 16, 2021)

Hey, have tried this already... Same result...


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## onzadog (Jan 6, 2008)

Do the lowers need squeezing in, or out to make it smoother? Perhaps "adjusting" the end caps or a different front hub might help.


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## Tobi1991 (Jul 16, 2021)

If i clamp the axle to 100,5mm instead of 100,0 the uppers drop under theit own weight  

Measured the hub with exactly 100,0-100,1. Maybe i could get thin spacer washers to expand to 100,5...


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## onzadog (Jan 6, 2008)

Does the hub manufacturer offer a boost conversion kit? Maybe try one of the wider spacers and have it turned down to suit.


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## jbrowning89 (May 11, 2019)

Does anyone have the resizing tool for 34mm stanchions? I have a Manitou Mattoc that has tight bushings. I saw some previous posts about requests to borrow or rent a tool. I'd be very interested in renting the resizing tool with a head made for 34mm Manitou stanchions from someone in the U.S. I'm in Seattle, WA.


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## jbrowning89 (May 11, 2019)

jbrowning89 said:


> Does anyone have the resizing tool for 34mm stanchions? I have a Manitou Mattoc that has tight bushings. I saw some previous posts about requests to borrow or rent a tool. I'd be very interested in renting the resizing tool with a head made for 34mm Manitou stanchions from someone in the U.S. I'm in Seattle, WA.


Oliver at Blue Liquid Labs is taking care of me!


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## Jakem (May 12, 2009)

Selling burnishing tool I purchased from Oliver in for sale section


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## racefit (Aug 26, 2010)

Jakem said:


> Selling burnishing tool I purchased from Oliver in for sale section


What size/type fork is it for?

Sent from my iPhone using Tapatalk


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## Jakem (May 12, 2009)

Lyrik 35/fox 36/fox 38 heads are included


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## EdSawyer (Mar 20, 2020)

Does anyone who has one of Oliver’s want to rent the tool? I need one for a Pike (35.07), would be happy to pay for the use of one and would put up a security deposit too of course. Thanks!


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## spokeywheeler (Dec 1, 2006)

EdSawyer said:


> Does anyone who has one of Oliver's want to rent the tool? I need one for a Pike (35.07), would be happy to pay for the use of one and would put up a security deposit too of course. Thanks!


I scored the one Jakem was selling, btw thanks Jakem! I'd be happy to loan it out. Shipping is a bit costly because of the size/weight but I just ordered a foam padded mailing box that should fit it nicely so it's not such a chore to pack and ship, and hopefully a little cheaper too. PM me if you're interested.


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## karpiel (Aug 27, 2010)

Den Capra said:


> Hi everyone this is my first post.
> Im v excited to read this thread as sticky forks have been a real pain for me in the last few years. I have a 2019 Lyrik which has been harsh and bouncy from day 1. I've played with pressures and rebounds but no improvement. I was on point of sending them in for warranty claim but I was fairly sure I would get told "Ah there's nothing wrong with them".
> Then I sent an email to Steve at Vorsprung and he mentioned bush sizing as 1 of the possible causes of my problem. And that lead to Google search which led to here. Anyone I've spoken to about their Lyriks tend to say "oh well they aren't very supple but they do give great support!"
> So here's hoping that I get a big improvement as soon as I get this tool from Liquid Labs.
> ...


Did you get sorted afterall Den Capra ? Wink, wink !


----------



## The_Bob (Jan 16, 2018)

Another bushing success story for me. The Pike on my new bike was feeling a bit sticky after 20 hours so I did a lower leg service and decided to open up the bushings a bit as well. Feeling super smooth now


----------



## Shark (Feb 4, 2006)

I have a 34 and a 35 on order. Looking forward to it.

Sent from my SM-G991U using Tapatalk


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## gatag (May 21, 2015)

Hello everyone. Hope to get an answer from the pros around here. Does anyone done the burnish process on a Zeb? Also, what size tool to order for 38 stanchions, .07 or 0.1? 

Hope to hear from you guys


----------



## Jukka4130 (Jun 21, 2020)

The 0.07 version of the burnishing tool is recommended for approximately 90% of the cases.


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## gatag (May 21, 2015)

Great! And what's the concensus for the Zeb? Does it need it? I know that for example the Mezzer is known for not reading it as much as others.


----------



## johnsogr (May 31, 2009)

My Mezzer was waaay tighter than both my Pike and Yari


Sent from my iPhone using Tapatalk


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## Jukka4130 (Jun 21, 2020)

There's no reason why Zeb would not benefit from the procedure just like other forks. I know one particular case in which the customer needed to warranty the fork since the bushings were so tight that the fork felt very harsh and was unable to use full travel even after Smashpot coil conversion (yes, with the appropriate spring rate).


----------



## OneTrustMan (Nov 11, 2017)

My tools finally arrived. 
Got the 35 and 36mm dies, plus the bushing removal tool including the insertion dies


----------



## MTB Engineer (Feb 15, 2021)

These have probably been linked before but where can I buy them?


----------



## OneTrustMan (Nov 11, 2017)

MTB Engineer said:


> These have probably been linked before but where can I buy them?


Just write an email to Oliver.
[email protected]
This is his business mail.


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## Johnmarison (Jul 9, 2021)

Hi,
Usually, if the bushings are tight, when you try to slot in the uppers into the lowers you would need a bit of force but once you actually resized them properly, the uppers would drop into the lowers thanks to gravity itself.


----------



## onzadog (Jan 6, 2008)

For those that have the bushing fitting and removal tools, where are you getting fox and Rockshox bushings? I've only been resizing them so far.


----------



## Danzzz88 (Jun 10, 2020)

So how slack are they supposed to be after burnishing, should the uppers just drop straight down into the lowers under gravity quickly, slowly, with wiper seals, without wiper seals?


----------



## onzadog (Jan 6, 2008)

Mine are set so that with seals in, but garter springs off, the CSU drops in under its own weight. The speed won't vary, they either clear, or they don't.

Once done, I also find it useful to invert the bike for a bit before riding just to get the top bushing covered in oil.


----------



## Danzzz88 (Jun 10, 2020)

Hmmm I don't think my bushes are super tight, though could benefit, except that when I take my CSU out the foek it looks like my stanchions bend inwards at the bottom, like the bottom are closer together than the crown. This is on a ZEB and heard someone else say the same thing too, though I'm thinking it might just be an optical illusion. If they are bending inwards though slightly, then no amount of burnishing will help.


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## CCS86 (Jan 6, 2020)

A slight lack of parallelism will cause a lot less friction than small bushings.

Sent from my Pixel 4 using Tapatalk


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## onzadog (Jan 6, 2008)

Depends which end is "wrong". Assuming to spacing at the crown is correct, it doesn't take much force to bring them parallel. If the bottom is the correct spacing and the crown is off, it will bind towards full travel.


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## CCS86 (Jan 6, 2020)

onzadog said:


> Depends which end is "wrong". Assuming to spacing at the crown is correct, it doesn't take much force to bring them parallel. If the bottom is the correct spacing and the crown is off, it will bind towards full travel.


Absolutely.

Sent from my Pixel 4 using Tapatalk


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## digev (Mar 7, 2019)

gatag said:


> Does anyone done the burnish process on a Zeb? Also, what size tool to order for 38 stanchions, .07 or 0.1?





Jukka4130 said:


> The 0.07 version of the burnishing tool is recommended for approximately 90% of the cases.


Absolutely 

Unless you get some weird tolerance stack-ups (worst case analysis) the 0.07mm die does the job! After re-burnishing 2 forks with the 0.1mm die, it made no improvement to the performance/sensitivity &#8230; in short, the right amount of clearance is great, more clearance doesn't change a thing.

No brands or models are immune to this, it's just the way mass production works! Not saying it's always bad, some might work fine!

Here's a ZEB before and after burnishing

BEFORE: Streamable Video
AFTER: Streamable Video

credits: @takumisuspensions


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## digev (Mar 7, 2019)

And another one

BEFORE: Streamable Video
AFTER: Streamable Video

credits: @thesuspensionlab


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## digev (Mar 7, 2019)

ZEB, 38 &#8230; same story (any forks, even new models can suffer from less than ideal bushings clearance)



















@suspensionworksnz


----------



## rstark18 (Apr 10, 2006)

digev said:


> And another one
> 
> BEFORE: Streamable Video
> AFTER: Streamable Video
> ...


In the after vid is it stopping at the lower bushing?


----------



## evernorth (Apr 13, 2020)

rstark18 said:


> In the after vid is it stopping at the lower bushing?


Could be, but it has damper and airshaft installed, so could also be just stuff bottoming in the lowers.

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## rstark18 (Apr 10, 2006)

So I finally got around to burnishing my 36. JHC it was hard to get the tool through on the air side. The damper side was very tight also but not as bad. 


After doing it I went to do the drop test and it took a slight push to keep it moving. That was with the wipers in. So I had to take the wiper out for my peace of mind. Without the wipers in the lower dropped right down. 

A big thanks to everyone in the thread. I’m going to try to get a ride in on Friday to see if I feel any difference.


----------



## digev (Mar 7, 2019)

And another one 

2021 Pike getting the real «ultimate» treatment 









Streamable Video


Watch this video on Streamable.




streamable.com














@cjsuspension


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## digev (Mar 7, 2019)

> Was asked what the difference between a fork that had tight bushings and one with correctly sized bushing was.
> 
> The fork has no damper, airspring or wiper seals so that's just the initial friction from the bushings.
> 
> Fork will be devouring the bumps now


Result: Streamable Video

source: @altasuspension


----------



## digev (Mar 7, 2019)

Now that should make it very easy to understand to anyone! Thanks RockShox for this simple yet accurate drawing 










If the stanchions can slide freely against the bushings, especially during step 1 and 3 when the most force/stress is applied &#8230; then the fork can do it's job and absorb the hit! The lower the friction between these 2 parts the better it works as _intended_

Source: https://www.sram.com/globalassets/d...ox/rockshox-suspension-theory-guide-rev-c.pdf


----------



## HollyBoni (Dec 27, 2016)

Anyone in the EU who does this for international customers? I'm located in Hungary and I have a new Pike Select+.


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## raceservicesuspension (Sep 17, 2016)

HollyBoni said:


> Anyone in the EU who does this for international customers? I'm located in Hungary and I have a new Pike Select+.


I'm in Austria and can do it for you.










PXL_20201029_110210165

PM me if you're interested


----------



## HollyBoni (Dec 27, 2016)

divdavdovDRR said:


> I'm in Austria and can do it for you.
> 
> View attachment 1946932
> 
> ...


That's great! I'll probably ride the bike as is until the weather gets bad, then i'll start tinkering with the fork and contact you then.

Anything else I should change to improve sensitivity (that doesn't cost a fortune)? Worth it to change the wiper seals to something else?


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## raceservicesuspension (Sep 17, 2016)

HollyBoni said:


> That's great! I'll probably ride the bike as is until the weather gets bad, then i'll start tinkering with the fork and contact you then.
> 
> Anything else I should change to improve sensitivity (that doesn't cost a fortune)? Worth it to change the wiper seals to something else?


SKF greens seals and motorex supergliss lower leg oil is a proven combo for reducing friction for relatively little money.


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## evernorth (Apr 13, 2020)

divdavdovDRR said:


> SKF greens seals and motorex supergliss lower leg oil is a proven combo for reducing friction for relatively little money.


Be aware about the supergliss, at warm temps it works awesome, but once it's below 5 degree Celsius it adds a whole lot lowspeed damping and feels awful. Shockcraft.nz does have handy table of lower leg oils for different temps. They recommend Motorex Polar or sticking with the RS 0w30 for lower temps.

Skf green seals are nice, but in case of Rock Shox forks you can also use the SKF Rock Shox Seals. They have a greyish color instead of the cheaper OE black dust seals. And are also made by SKF. Part No. 00.4318.045.004

Cheers

Gesendet von meinem Pixel 5 mit Tapatalk


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## Jukka4130 (Jun 21, 2020)

With what forks have you used SuperGliss? My experiences with it have been mixed at best.


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## HollyBoni (Dec 27, 2016)

evernorth said:


> Be aware about the supergliss, at warm temps it works awesome, but once it's below 5 degree Celsius it adds a whole lot lowspeed damping and feels awful. Shockcraft.nz does have handy table of lower leg oils for different temps. They recommend Motorex Polar or sticking with the RS 0w30 for lower temps.
> 
> Skf green seals are nice, but in case of Rock Shox forks you can also use the SKF Rock Shox Seals. They have a greyish color instead of the cheaper OE black dust seals. And are also made by SKF. Part No. 00.4318.045.004
> 
> ...


That's good news, not too big on aesthetics but i'm not a fan of those green seals. 

Are you talking about these?








RockShox Upgrade Kit for Flangeless Dust Seals and 35 mm Stanchion Tubes


The Upgrade Kit for flangeless dust seals and 35 mm stanchion tubes from RockShox - clean and tigh With the RockShox Upgrade Kit for flangeless dust seals and 35 mm stanchion tubes, dirt stays where it belongs: Away from your suspension fork! The ext




www.bike-components.de





What's the difference between flanged and flangless seals?


----------



## evernorth (Apr 13, 2020)

HollyBoni said:


> That's good news, not too big on aesthetics but i'm not a fan of those green seals.
> 
> Are you talking about these?
> 
> ...


Yeah, those are the Seals I was referring to. Its also written in the product description.

Flanged seals have been used in older models of forks. Nowadays most forks come with non-flanged seals.

Flanged seals have a lip that sits on top of the bore where the seal sits in, the flange assures that the seal will sit flush.

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----------



## digev (Mar 7, 2019)

Streamable Video


Watch this video on Streamable.




streamable.com





@altasuspension


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## minisman (Mar 31, 2009)

Hi everyone,
I'm convinced my bushings are binding in my new fork, so I contacted Olly about ordering a kit, and it was just going to be too expensive for me for a one off thing.
He offered a solution of using a hone from an automotive shop.for brake pistons.
Before I try this does anyone have thoughts on what I should consider when doing this?
Is honing method? Crosshatch like pistons? Grit\coursness ? Rotation Speed? Anything?


----------



## digev (Mar 7, 2019)

minisman said:


> Hi everyone,
> I'm convinced my bushings are binding in my new fork, so I contacted Olly about ordering a kit, and it was just going to be too expensive for me for a one off thing.
> He offered a solution of using a hone from an automotive shop.for brake pistons.
> Before I try this does anyone have thoughts on what I should consider when doing this?
> Is honing method? Crosshatch like pistons? Grit\coursness ? Rotation Speed? Anything?


HeyHey!!

Before thinking about the solution to use, make sure you have a problem to solve 

Don't be convinced! KNOW!

Disassemble/empty your fork and test the chassis on its own &#8230; it's been explained «How» many times in this thread but if you can't find it, get back to post #1

Good luck


----------



## rstark18 (Apr 10, 2006)

minisman said:


> Hi everyone,
> I'm convinced my bushings are binding in my new fork, so I contacted Olly about ordering a kit, and it was just going to be too expensive for me for a one off thing.
> He offered a solution of using a hone from an automotive shop.for brake pistons.
> Before I try this does anyone have thoughts on what I should consider when doing this?
> Is honing method? Crosshatch like pistons? Grit\coursness ? Rotation Speed? Anything?


What fork do you have?


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## JB450 (Mar 31, 2019)

minisman said:


> Hi everyone,
> I'm convinced my bushings are binding in my new fork, so I contacted Olly about ordering a kit, and it was just going to be too expensive for me for a one off thing.
> He offered a solution of using a hone from an automotive shop.for brake pistons.
> Before I try this does anyone have thoughts on what I should consider when doing this?
> Is honing method? Crosshatch like pistons? Grit\coursness ? Rotation Speed? Anything?


Don't use a honing tool.

You definitely do not want to score/scratch the bushing surface, that is why the bushing tool is just a solid chunk of appropriately machined stainless steel.

In most cases the bushings are out of round (oval shaped from installation) and the burnishing tool is basically just forcing the bushing back into round.


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## jayblack (Dec 29, 2009)

Their tool looks different, but the end effect is the same.


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## HollyBoni (Dec 27, 2016)

A random question, I hope that's okay here.

In a fork what does the lower leg oil lubricate exactly? I've read that it's supposed to lubricate the bushings, but how does it get to the bushings and not just sit at the bottom? When doing a lower leg service, are you supposed to put oil on the bushings?


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## Senderdeep (Aug 26, 2021)

HollyBoni said:


> A random question, I hope that's okay here.
> 
> In a fork what does the lower leg oil lubricate exactly? I've read that it's supposed to lubricate the bushings, but how does it get to the bushings and not just sit at the bottom? When doing a lower leg service, are you supposed to put oil on the bushings?


In theory the oil is supposed to slosh around and make it up to the foam rings and bushings. Storing the bike upside down can help keep the foam rings saturated before your ride.

When performing a lower leg service you are supposed to soak the foam rings before putting the legs back in.


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## jayblack (Dec 29, 2009)

HollyBoni said:


> A random question, I hope that's okay here.
> 
> In a fork what does the lower leg oil lubricate exactly? I've read that it's supposed to lubricate the bushings, but how does it get to the bushings and not just sit at the bottom? When doing a lower leg service, are you supposed to put oil on the bushings?


Just imagine putting oil in a syringe, sealing the bottom end and then compressing the plunger. On the way in air gets compressed when the plunger is released oil splashesh everyhere. Lower legs are part of the air spring and they play significant role in the end stroke ramp up. Super light riders are struggling to bottom out their forks partly because of this.


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## HollyBoni (Dec 27, 2016)

Got it, thanks guys!


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## JB450 (Mar 31, 2019)

HollyBoni said:


> A random question, I hope that's okay here.
> 
> In a fork what does the lower leg oil lubricate exactly? I've read that it's supposed to lubricate the bushings, but how does it get to the bushings and not just sit at the bottom? When doing a lower leg service, are you supposed to put oil on the bushings?


Darren from Push industries once said in a podcast that one of the easier and best performance gains on the trail was to stand with you bike upright (like how you would store it hanging on the wall) for a minute or so before dropping into the trail.

It lets the lower leg lube flow back into the bushes.


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## ziscwg (May 18, 2007)

JB450 said:


> Darren from Push industries once said in a podcast that one of the easier and best performance gains on the trail was to stand with you bike upright (like how you would store it hanging on the wall) for a minute or so before dropping into the trail.
> 
> It lets the lower leg lube flow back into the bushes.


I store my bike that way (vertical). Both of my wheels are against the vertical wall. I know the foam rings are soaked. How would I know? I have a Smashpot coil. It uses 120ml of 20wt oil. I kinda have a lot of this Lucas 20wt fork oil that is green. So, when I do a lower service, one foam ring is green and the other is Fox gold.


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## rstark18 (Apr 10, 2006)

ziscwg said:


> I store my bike that way (vertical). Both of my wheels are against the vertical wall. I know the foam rings are soaked. How would I know? I have a Smashpot coil. It uses 120ml of 20wt oil. I kinda have a lot of this Lucas 20wt fork oil that is green. So, when I do a lower service, one foam ring is green and the other is Fox gold.


The only problem with storing the bike that way is any air bubbles that might be in your reservoir will migrate down the line.


----------



## onzadog (Jan 6, 2008)

While I'm getting ready for a ride, there's a bit of old inner tube over the brake levers to keep the system closed and the bike flipped just the give those busings a soak before riding.

You could use the same trick when storing vertically.


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## romphaia (Sep 7, 2014)

jayblack said:


> Just imagine putting oil in a syringe, sealing the bottom end and then compressing the plunger. On the way in air gets compressed when the plunger is released oil splashesh everyhere. Lower legs are part of the air spring and they play significant role in the end stroke ramp up. Super light riders are struggling to bottom out their forks partly because of this.


The problem is that isn't very efficient. It does take some pushing and splashing before oil reaches up to the lower bushes; then when oil clogs the gaps and between the bushes and stanchions, the pressure difference building in the lowers during compression will force it above the lower bushes, but you can bet it will never reach the upper ones. For that you have to rely on the foam rings, and they dry up eventually unless keeping the bike upside down for some time.


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## jasonp22 (Oct 5, 2016)

rstark18 said:


> The only problem with storing the bike that way is any air bubbles that might be in your reservoir will migrate down the line.


If that's the case, the brakes need a bleed.


----------



## wschruba (Apr 13, 2012)

romphaia said:


> The problem is that isn't very efficient. It does take some pushing and splashing before oil reaches up to the lower bushes; then when oil clogs the gaps and between the bushes and stanchions, the pressure difference building in the lowers during compression will force it above the lower bushes, but you can bet it will never reach the upper ones. For that you have to rely on the foam rings, and they dry up eventually unless keeping the bike upside down for some time.


I don't necessarily see this problem. When I open up a fork that I've serviced, for me, the foam rings are still saturated several months later. I don't store my bikes anything other than wheel-down (they're on lifts in the garage). I _could_ see this happening if you stored a bike for an extended period of time with no riding--say, 6 months--but then other things would definitely need attention, too. Capillary action is stronger than people give it credit, but then, it has to fight the foam ring trying to do the same thing.

If I remember to, I should take one of the old foam rings, clean it, dry it, and then soak it in oil/place it on a small standoff in a tupperware container to see what happens over the months. My gut instinct says that a closed environment is not going to see meaningful migration of oil out of the foam. Even a sponge filled with water will stay wet for some time if you place it in a container or bag.


----------



## sean44 (Dec 10, 2018)

Trying to figure out if my forks are suffering from tight bushings. Doing the drop test on the work bench all seems fine but when i load the forks when in the frame by pushing down on top of the bars everything locks up mid travel. Is this could this just be seals?


----------



## onzadog (Jan 6, 2008)

Have you tried the bench drop test with the wheel in? It could be that the hub is forcing the lowers out of alignment.


----------



## sean44 (Dec 10, 2018)

onzadog said:


> Have you tried the bench drop test with the wheel in? It could be that the hub is forcing the lowers out of alignment.


I have not tried that but its on a fox 38 so the axle position is set against the hub.


----------



## EdSawyer (Mar 20, 2020)

Has anyone heard from Oliver @ blue liquid labs lately? I ordered burnishing tools from him, paid via Paypal on 9/22 since he said they were ready, and since then nothing. No replies to 3 different emails... wondering why he is ghosting me, might have to do a chargeback on the paypal but hopefully not...


----------



## rstark18 (Apr 10, 2006)

EdSawyer said:


> Has anyone heard from Oliver @ blue liquid labs lately? I ordered burnishing tools from him, paid via Paypal on 9/22 since he said they were ready, and since then nothing. No replies to 3 different emails... wondering why he is ghosting me, might have to do a chargeback on the paypal but hopefully not...


Mine took 6 weeks. I think that a little longer than usual though.


----------



## EdSawyer (Mar 20, 2020)

Yeah, I ordered them back in August, so at least 6 weeks. Then he said "they are ready", I paid the same day. Now so far, nothing... don't want to be needy but "ready" means ready to ship, IMNSHO.


----------



## onzadog (Jan 6, 2008)

It took a little while but he's legit. I'd give it a bit more time.


----------



## digev (Mar 7, 2019)

EdSawyer said:


> Yeah, I ordered them back in August, so at least 6 weeks. Then he said "they are ready", I paid the same day. Now so far, nothing... don't want to be needy but "ready" means ready to ship, IMNSHO.


Hi,

Try sending him a message via Instagram! He's pretty fast at replying. If not, let me know and I'll get in touch!

Rest assured, you will get the tool 

The last shipment took forever as well so no worries.


----------



## EdSawyer (Mar 20, 2020)

Thanks! I don't have/use instagram (plus it's down at the moment!), good to know it should get here eventually.


----------



## EdSawyer (Mar 20, 2020)

ok, editing this - Oliver got in touch, it was just an oversight on his part. I am down off the cliff and everything is back to normal! ;-)


----------



## evernorth (Apr 13, 2020)

I've just chatted with him about an order I placed. Everything fine, he will get back to you eventually. 
From what he told me some weeks ago, he is very busy due to new machines. It's also not my first order with him and everything went smoothly the first time as well.

Ride on! 

Gesendet von meinem Pixel 5 mit Tapatalk


----------



## rstark18 (Apr 10, 2006)

EdSawyer said:


> Even after 2 more emails he is still ghosting me. Not even the decency of a reply to say “it’s late…” or anything. Sadly I think I have to say don’t count on this guy to make anything for you and expect basically no communication after you send money.
> 
> It would be nice to actually get the parts. I paid him 20 days ago when he said they were ready. If anyone is in contact with him on instagram please ping him to see what’s up for me if you would.


Maybe your email got accidentally flagged as spam. Try sending him a message from a different email address.


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## digev (Mar 7, 2019)

EdSawyer said:


> It would be nice to actually get the parts. I paid him 20 days ago when he said they were ready. If anyone is in contact with him on instagram please ping him to see what’s up for me if you would.


Nobody likes that kind of situation! Please PM me your initials and I'll take care of it!

You have a great one (and don’t worry)


----------



## digev (Mar 7, 2019)

EdSawyer said:


> If anyone is in contact with him on instagram please ping him to see what’s up for me if you would.


Got in touch with him! He's just replied to you and has offered to send you an extra die at no charge to make it right!

Hope you are more relaxed now 

Happy burnishing


----------



## CCS86 (Jan 6, 2020)

wschruba said:


> I don't necessarily see this problem. When I open up a fork that I've serviced, for me, the foam rings are still saturated several months later. I don't store my bikes anything other than wheel-down (they're on lifts in the garage). I _could_ see this happening if you stored a bike for an extended period of time with no riding--say, 6 months--but then other things would definitely need attention, too. Capillary action is stronger than people give it credit, but then, it has to fight the foam ring trying to do the same thing.
> 
> If I remember to, I should take one of the old foam rings, clean it, dry it, and then soak it in oil/place it on a small standoff in a tupperware container to see what happens over the months. My gut instinct says that a closed environment is not going to see meaningful migration of oil out of the foam. Even a sponge filled with water will stay wet for some time if you place it in a container or bag.


It's not the sitting that dries them. It's the fact that the stanchion keeps rubbing it, stealing a small amount of oil, which ends up migrating past the dust seal and getting wiped off.

Sent from my Pixel 4 using Tapatalk


----------



## homey2 (Apr 6, 2006)

Jakem said:


> Lyrik 35/fox 36/fox 38 heads are included


Pm’ed you


----------



## EdSawyer (Mar 20, 2020)

Thanks for the help! He did get in touch, I am down off the cliff now. It seems like things just slipped through the cracks somehow. Very generous of him re: Extra die (though I will probably decline as I don't really need any other ones... maybe a 32 but not sure if it can do that small). 

Thanks again, Oliver is still the man!

-Ed



digev said:


> Got in touch with him! He's just replied to you and has offered to send you an extra die at no charge to make it right!
> 
> Hope you are more relaxed now
> 
> Happy burnishing


----------



## HollyBoni (Dec 27, 2016)

What are these 4 washers that I got with the SKF seals? 🤦‍♂️ (Rockshox 35mm kit)


----------



## onzadog (Jan 6, 2008)

Crush washers.
If you look closely at the bolts you removed, there's a recess with a black plastic seal in it.


----------



## HollyBoni (Dec 27, 2016)

onzadog said:


> Crush washers.
> If you look closely at the bolts you removed, there's a recess with a black plastic seal in it.


Thanks!

Waiting for the weather to turn bad until I disassemble the fork. I really really hope i'm gonna find out that the bushings are crazy tight. 😅


----------



## EJ_92606 (Jul 11, 2004)

So what's the scoop with the green seals? Are they low friction? I read conflicting info where somewhere it said that all the seals for current forks are low friction?


----------



## HollyBoni (Dec 27, 2016)

EJ_92606 said:


> So what's the scoop with the green seals? Are they low friction? I read conflicting info where somewhere it said that all the seals for current forks are low friction?


Not sure. Rockshox sells cheaper seals and a more expensive "upgrade kit". I was told here that the more expensive Rockshox seals are similar/the same as the green SKF ones. I got the green ones because they were in stock, and also they were about €10 more expensive than the Rockshox upgrade kit, so that means they must be better! 😁
I do hope that my Pike Select+ doesn't have seals already that perform exactly the same as these. But if it does it's not the end of the world... At least i'll learn how to change seals.


----------



## EJ_92606 (Jul 11, 2004)

When you do the service, can you take a picture of the seals side by side so we can see the difference? Interested to hear if you notice a difference in ride quality as well.


----------



## rstark18 (Apr 10, 2006)

I doubt anyone can tell the difference between seals once they’re installed. 

Maybe a better test would be to take each seal brand before they’re installed, grease it up a little, and slide it up and down the stanchion to feel for resistance. If there is a difference you’d be able to feel it this way. 
If anyone does this please post a video.


----------



## NordieBoy (Sep 26, 2004)

rstark18 said:


> Maybe a better test would be to take each seal brand before they’re installed, grease it up a little, and slide it up and down the stanchion to feel for resistance. If there is a difference you’d be able to feel it this way.
> If anyone does this please post a video.


In slowmo.
With soft music.


----------



## HollyBoni (Dec 27, 2016)

EJ_92606 said:


> When you do the service, can you take a picture of the seals side by side so we can see the difference? Interested to hear if you notice a difference in ride quality as well.


Sure thing, but keep in mind that I'll do a few other things to the fork (hopefully) so the difference won't come from just the seals.



NordieBoy said:


> In slowmo.
> With soft music.


🍌🍌🍌


----------



## digev (Mar 7, 2019)

For what it’s worth 



digev said:


> Quick proof of concept
> 
> Nothing fancy or very accurate but the point was to (try) to measure the friction force before and after burnishing and eventually find out how the overall friction is spread/shared across the other components in the fork ...


Swapping the seals _can_ improve the static/dynamic friction but in the great scheme of things it’s a _very minor_ improvement! Forthcoming dual compound seals from SKF should increase that gain a little more but for the time being if you rely on traditional designs (and reputable brands) you’ll see no or very little improvements. I won’t name a brand, stating they have the lowest friction coefficient on the market but if you try them you’ll see oil sweating past the seals and drip onto the lowers … seals should by definition prevent that (what’s on one side should not migrate into the other and vice versa)! In short they should be low friction AND seal properly  (not an easy task if you think about it because it's kind of conflicting)


----------



## HollyBoni (Dec 27, 2016)

digev said:


> I won’t name a brand, stating they have the lowest friction coefficient on the market but if you try them you’ll see oil sweating past the seals and drip onto the lowers …


I really hope you're not talking about green SKF seals! 😁

Can you guys recommend a method for taking out seals without destroying them (if that's possible)?


----------



## onzadog (Jan 6, 2008)

If the seals are still good, why would you take them out?


----------



## HollyBoni (Dec 27, 2016)

onzadog said:


> If the seals are still good, why would you take them out?


I'm trying to make the fork as smooth and sensitive as possible. I thought these seals would help with that, maybe that's completely dumb. I'd like to save the "old" seals in case the new ones don't fit for some reason, or if I screw something up when installing them etc.
Also as far as I understand, to even check how free the stanchions slide in the bushings, I need to take out the damper, spring, and seals anyways?


----------



## SleepeRst (Nov 30, 2011)

It happened guys, my bushings in my pike are seeming to loosen up after having been burnished since March. I've been hearing a front end rattle for a little while now and finally pinpointed it to the fork. Sticking a finger in between my stanchion and arch, and rocking the fork back and forth makes it very obvious its coming from the bushings.

I cannot tell how bad it is, and it doesn't really make a huge racket, and the fork seems to operate the same as it always has post burnishing. For me it is rather annoying as I hate any amount of noise on my bike, so I will be looking into bushing replacements over the winter when I get the fork fully serviced.

For what its worth I have performed the lowers service twice since March, clean and replace oil/foam rings.

Any recommendations or ideas? I love the performance of having the fork burnished but I'm not too keen on having the bushings last less than a year.


----------



## onzadog (Jan 6, 2008)

@SleepeRest, are you inverting the fork between rides? Do they feel better just after a lowers service?

@HollyBonni, I found that leaving the seals in but removing the damper, foam rings and the garter spring from the top of the seal, I could still get the CSU to drop in under its own weight.

I don't know of any way to remove the seals in a resuseable condition.


----------



## sstefanov (Sep 18, 2005)

@SleepeRest - if your fork bushings are sized correctly, but dry (no lube), then there will be a minor play. If lubed and no play - then all is good.

PS: I do not know how much do your ride, but with my riding I have to do lower leg service every 2 to 3 months...


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## digev (Mar 7, 2019)

Quick chart showing the friction forces across all the components inside _a friend's_ Pike and comparing the overall results before and after burnishing! I used the values recorded months ago when I was trying to find out how the friction was spread/shared across all the components (_inside the fork_). Here's a link to this post:


digev said:


> Quick proof of concept


The coil conversion option is just for fun (it's also what I ride)! Do the same "measurements" on your fork(s) and find out for yourself


----------



## rain164845 (Jul 6, 2008)

Does anyone have a 35mm burnishing tool that they would rent to me in the USA?
Thank you!

Sent from my SM-G975U using Tapatalk


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## digev (Mar 7, 2019)

The less the better, no matter the vehicle 

Source: How to Remove Oversteer and Understeer – NEW – Suspension Secrets


----------



## ungod (Apr 16, 2011)

Burnish those control arm bushings!


----------



## Dougal (Jan 23, 2004)

digev said:


> Quick chart showing the friction forces across all the components inside _a friend's_ Pike and comparing the overall results before and after burnishing! I used the values recorded months ago when I was trying to find out how the friction was spread/shared across all the components (_inside the fork_). Here's a link to this post:
> 
> The coil conversion option is just for fun (it's also what I ride)! Do the same "measurements" on your fork(s) and find out for yourself
> 
> View attachment 1952645


That's an incredible amount of stiction you're starting with!


----------



## EJ_92606 (Jul 11, 2004)

ungod said:


> Burnish those control arm bushings!


Check your linkage bushings, you won't regret it


----------



## EdSawyer (Mar 20, 2020)

Forget bushings. Heim joints FTW


----------



## HollyBoni (Dec 27, 2016)

Dissassembled my Pike today. Looks pretty good to me, what do you guys think? Checked with the wheel in as well, same result. The uppers easily drop in the lowers.






This is how the air spring looked:










I barely see any grease on there. When I move the seal head up and down, it doesn't feel smooth, but a bit "notchy". When I moved the foot nut up and down while the air spring was in the fork, it didn't seem super smooth either. Is that normal? 

BTW this is a C1, right?


----------



## dan l (Oct 16, 2015)

digev said:


> Quick chart showing the friction forces across all the components inside _a friend's_ Pike and comparing the overall results before and after burnishing! I used the values recorded months ago when I was trying to find out how the friction was spread/shared across all the components (_inside the fork_). Here's a link to this post:
> 
> The coil conversion option is just for fun (it's also what I ride)! Do the same "measurements" on your fork(s) and find out for yourself
> 
> View attachment 1952645


With than much friction, you would expect the anodizing on the stanchions to be damaged. Do you have pictures of them?


----------



## CrozCountry (Mar 18, 2011)

digev said:


> Absolutely
> 
> Unless you get some weird tolerance stack-ups (worst case analysis) the 0.07mm die does the job! After re-burnishing 2 forks with the 0.1mm die, it made no improvement to the performance/sensitivity &#8230; in short, the right amount of clearance is great, more clearance doesn't change a thing.
> 
> ...


Can you make one of those videos one leg at a time. I suspect some of the friction is from the legs not being concentric with the bushings.


----------



## wschruba (Apr 13, 2012)

HollyBoni said:


> Dissassembled my Pike today. Looks pretty good to me, what do you guys think? Checked with the wheel in as well, same result. The uppers easily drop in the lowers.
> 
> 
> 
> ...


Yes, that's a C1. You can put an 8mm hex in the spring piston, and turn off the foot nut with a wrench (12mm?). Apply some slickoleum to the quad in the seal head, and reassemble. You'll need red loctite for the foot nut. IIRC, the torque is quite low (5, 6[?] NM). Remember that the loctite fixtures in 10 minutes, but needs to cure for 24 hours, so don't do it right before you go for a ride. Wipe the excess off when you finish tightening the foot nut onto the shaft.

When you're ready to reassemble all the way, swipe some slickoleum on the piston quad, then swirl some on a rag, and push it through the stanchion with a [wood or plastic] stick.


----------



## HollyBoni (Dec 27, 2016)

wschruba said:


> Yes, that's a C1. You can put an 8mm hex in the spring piston, and turn off the foot nut with a wrench (12mm?). Apply some slickoleum to the quad in the seal head, and reassemble. You'll need red loctite for the foot nut. IIRC, the torque is quite low (5, 6[?] NM). Remember that the loctite fixtures in 10 minutes, but needs to cure for 24 hours, so don't do it right before you go for a ride. Wipe the excess off when you finish tightening the foot nut onto the shaft.
> 
> When you're ready to reassemble all the way, swipe some slickoleum on the piston quad, then swirl some on a rag, and push it through the stanchion with a [wood or plastic] stick.


Thanks for the info, I'll assemble the fork tonight. Is blocking the transfer port with grease a real thing, or just an internet myth?

What about the bushings, are they perfectly fine? Is the "shh" noise normal as the stanchions slide up and down? I hear it when the fork is assembled as well. I checked out two other Pikes, and I don't think they made this noise.


----------



## wschruba (Apr 13, 2012)

HollyBoni said:


> Thanks for the info, I'll assemble the fork tonight. Is blocking the transfer port with grease a real thing, or just an internet myth?
> 
> What about the bushings, are they perfectly fine? Is the "shh" noise normal as the stanchions slide up and down? I hear it when the fork is assembled as well. I checked out two other Pikes, and I don't think they made this noise.


Grease can block the port, but you'd have to go hog-wild to do it more than transiently. 50psi is more than enough to blow the port clear.

Just to be clear, the bushings are making noise, even when lubricated?


----------



## HollyBoni (Dec 27, 2016)

wschruba said:


> Grease can block the port, but you'd have to go hog-wild to do it more than transiently. 50psi is more than enough to blow the port clear.
> 
> Just to be clear, the bushings are making noise, even when lubricated?


In the video there is no oil on the bushings, but when the fork is assembled and I compress it, I can clearly hear that "shh" sound, just not as loud.


----------



## wschruba (Apr 13, 2012)

HollyBoni said:


> In the video there is no oil on the bushings, but when the fork is assembled and I compress it, I can clearly hear that "shh" sound, just not as loud.


I would suggest cleaning the lowers well, first, to rule out contaminants... But also to give your a good look at clean bushings. You can use isopropanol, but suspension cleaner works, too, if your are near a motorcycle shop. Split a 1/2" dowel about 2-3 inches, and put a rag in the split. Spray/swab.

The bushings should visually look cream colored. If you can reach the upper bushings with a finger, it should feel smooth by itself--the lower bushings will have to suffice with a look down with a light, unless you happen to have a borescope.

_Edit_ what kind of oil are you using?


----------



## HollyBoni (Dec 27, 2016)

wschruba said:


> I would suggest cleaning the lowers well, first, to rule out contaminants... But also to give your a good look at clean bushings. You can use isopropanol, but suspension cleaner works, too, if your are near a motorcycle shop. Split a 1/2" dowel about 2-3 inches, and put a rag in the split. Spray/swab.
> 
> The bushings should visually look cream colored. If you can reach the upper bushings with a finger, it should feel smooth by itself--the lower bushings will have to suffice with a look down with a light, unless you happen to have a borescope.
> 
> _Edit_ what kind of oil are you using?


Thanks. I'll clean out everything thoroughly and we'll see. I noticed from day one that the fork made this noise.

Right now i'm using Rockshox 0W30. I'd like to try Supergliss in the spring/summer.

Edit: Just assembled the fork. I think it feels a bit better but we'll see. I also bled the damper and I think now I can feel the compression dial actually doing something (Charger 2.1 RC).

I forgot to take pics, but the SKF seals are definitely different than what came stock in my Pike Select+. The design is different and the material feels different. We'll see if I notice anything different in terms of "performance".


----------



## evernorth (Apr 13, 2020)

Got my second order from Oliver delivered today. First time I ordered only the Burnishing heads and handle for 35/36 forks. But since then I've started a suspension business and ordered a full set of his busing extraction/Insertion tools as well as the additional Burnishing heads. 

Big shout-out to Blueliquid Labs for the quality of his tools! Making forks happy (again)!









Gesendet von meinem Pixel 5 mit Tapatalk


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## H.vice (Sep 18, 2021)

@evernorth @digev Who in Europe can do the bushing clearance.for a brand new 2021 Manitou R7 pro (32mm legs) ?
I would like to also have the oil changed with a lower weight for the winter. Maybe with the Maxima Shock Oil 3wt.


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## croakies (Mar 4, 2011)

This is a long shot but does anyone in the SF bay area have a 38mm head for Olivers/Blueliquid tool I could borrow? I have 37mm and 35mm but just got a new bike with a 38 on it.


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## HollyBoni (Dec 27, 2016)

So I think these SKF seals might be a bit too low friction? 😁


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## MTB Engineer (Feb 15, 2021)

My SKF wipers started leaking at 250h of riding. Why won’t anything last anymore!? 😂


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## HollyBoni (Dec 27, 2016)

MTB Engineer said:


> My SKF wipers started leaking at 250h of riding. Why won’t anything last anymore!? 😂


These have 2 rides on them. Only one of them is leaking at a certain spot. Although I think there is a tiny bit of oil on both stanchions because i'm seeing more dust on them than usual. 

The oil leak itself is not a big deal, my issue is that if they're letting oil out, what are they letting in?


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## wschruba (Apr 13, 2012)

HollyBoni said:


> These have 2 rides on them. Only one of them is leaking at a certain spot. Although I think there is a tiny bit of oil on both stanchions because i'm seeing more dust on them than usual.
> 
> The oil leak itself is not a big deal, my issue is that if they're letting oil out, what are they letting in?


Yes...but there have been few reports of stuff like that. Worth shooting a message off to SKF.


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## evernorth (Apr 13, 2020)

wschruba said:


> Yes...but there have been few reports of stuff like that. Worth shooting a message off to SKF.


Also remember if its kinda cold where you are and you used supergliss, that stuff gets so thick that it will be pulled through the seals, no matter what brand. 

Gesendet von meinem Pixel 5 mit Tapatalk


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## HollyBoni (Dec 27, 2016)

wschruba said:


> Yes...but there have been few reports of stuff like that. Worth shooting a message off to SKF.


Yeah, i'll shoot a message to the shop I bought it from first and we'll see what they say.



evernorth said:


> Also remember if its kinda cold where you are and you used supergliss, that stuff gets so thick that it will be pulled through the seals, no matter what brand.
> 
> Gesendet von meinem Pixel 5 mit Tapatalk


I'm using RS 0W-30 oil right now. 

I thought it's easier for lower viscosity oil to leak past the seals. It's the opposite?


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## evernorth (Apr 13, 2020)

HollyBoni said:


> Yeah, i'll shoot a message to the shop I bought it from first and we'll see what they say.
> 
> I'm using RS 0W-30 oil right now.
> 
> I thought it's easier for lower viscosity oil to leak past the seals. It's the opposite?


Okay with 0w30 that shouldn't really happen. Sadly the Supergliss gets to thick when its cold, thats why it gets pulled up. The RS 0w30 performs fine in cold weather.


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## jsma09 (Nov 24, 2018)

HollyBoni said:


> So I think these SKF seals might be a bit too low friction? 😁
> 
> View attachment 1954786


I’ve seen instances where these SKF green seals were so tight that started to eat the Kashima coating.




evernorth said:


> Okay with 0w30 that shouldn't really happen. Sadly the Supergliss gets to thick when its cold, thats why it gets pulled up. The RS 0w30 performs fine in cold weather.


I happen to have a few spare liters of Supergliss 32K if you’re interested. Recently sent some to a couple of guys over in Germany.


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## GH28 (Jun 16, 2014)

Anyone in Socal have a 38mm burnishing tool set I could rent?


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## HollyBoni (Dec 27, 2016)

jsma09 said:


> I’ve seen instances where these SKF green seals were so tight that started to eat the Kashima coating.


Whaaaaat?  I thought these things were supposed to be high quality.

BTW I sent a photo about the leak to Bike24 and they are sending me new seals free of charge. Although i'm not that stoked on using them anymore... 😅


----------



## spokeywheeler (Dec 1, 2006)

croakies said:


> This is a long shot but does anyone in the SF bay area have a 38mm head for Olivers/Blueliquid tool I could borrow? I have 37mm and 35mm but just got a new bike with a 38 on it.


PM Sent


----------



## e.grinbergs (Nov 8, 2021)

divdavdovDRR said:


> I'm in Austria and can do it for you.
> 
> View attachment 1946932
> 
> ...


Hi,

I am also interested for my Yari (35 mm), can you help me as well? I am in EU.


----------



## raceservicesuspension (Sep 17, 2016)

e.grinbergs said:


> Hi,
> 
> I am also interested for my Yari (35 mm), can you help me as well? I am in EU.


 PMing you now.


----------



## ziscwg (May 18, 2007)

rstark18 said:


> The only problem with storing the bike that way is any air bubbles that might be in your reservoir will migrate down the line.


Just to clarify..
front wheel up, rear down. So, there's almost no chance for the rear brake. The front could get an air bubble. With my hose routing, it's still very unlikely. There's a spot where the hose angle drops below horizontal. 

In addition, if I did feel any air in the line when riding, I would bleed it out right away.


----------



## ziscwg (May 18, 2007)

jasonp22 said:


> If that's the case, the brakes need a bleed.


Yep, and mine do not. So, no braking issues from air while riding.


----------



## rstark18 (Apr 10, 2006)

I never said thanks to everyone in this thread. If not for this thread I would have never thought of burnishing. 
After getting the tool from Oliver my 36 is buttery smooth, well at least compared to what they were. What a difference.


----------



## digev (Mar 7, 2019)

rstark18 said:


> I never said thanks to everyone in this thread. If not for this thread I would have never thought of burnishing.
> After getting the tool from Oliver my 36 is buttery smooth, well at least compared to what they were. What a difference.


Very happy for you because that’s exactly why this thread was created for in the first place  Create some awareness about something that was flying under the radar (for most of us) and offer a way to act on it if necessary! Thanks for the feedback, keep it smooth


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## EJ_92606 (Jul 11, 2004)

Wish there were more options for purchasing a tool. I placed an order two months ago with Oliver (est. 3 week delivery) and he's not responding to emails.


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## GH28 (Jun 16, 2014)

EJ_92606 said:


> Wish there were more options for purchasing a tool. I placed an order two months ago with Oliver (est. 3 week delivery) and he's not responding to emails.


It's the repeat posts like that that have me hesitating to buy a set of tools myself. Curious how these turn out.


----------



## karpiel (Aug 27, 2010)

Does anybody know if the diametric tolerance between bushes and stanchions is the same on a FOX 38 and a Zeb ?


----------



## Blkdoutindustries (Feb 23, 2020)

GH28 said:


> It's the repeat posts like that that have me hesitating to buy a set of tools myself. Curious how these turn out.


I got a set from him and yes, it was a couple of weeks longer than expected but I did get everything I ordered with no issues, I got the 34,35,36,37 and 38 dies with the tool


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## GH28 (Jun 16, 2014)

Blkdoutindustries said:


> I got a set from him and yes, it was a couple of weeks longer than expected but I did get everything I ordered with no issues, I got the 34,35,36,37 and 38 dies with the tool


What uses a 37mm stanchion?


----------



## Blkdoutindustries (Feb 23, 2020)

GH28 said:


> What uses a 37mm stanchion?


Manitou Mezzer that I'm running on my trail bike


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## JB450 (Mar 31, 2019)

EJ_92606 said:


> Wish there were more options for purchasing a tool. I placed an order two months ago with Oliver (est. 3 week delivery) and he's not responding to emails.





GH28 said:


> It's the repeat posts like that that have me hesitating to buy a set of tools myself. Curious how these turn out.


It can take a bit longer but he always delivers..









Tight Bushings = Harshness


Yeah, I ordered them back in August, so at least 6 weeks. Then he said "they are ready", I paid the same day. Now so far, nothing... don't want to be needy but "ready" means ready to ship, IMNSHO.




www.mtbr.com


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## CrozCountry (Mar 18, 2011)

How do you measure the inner diameter of the bushings while burnishing? Do you use an Internal Micrometer?


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## EJ_92606 (Jul 11, 2004)

The burnishing head is properly sized, so there is no measuring of the bushing.


----------



## wschruba (Apr 13, 2012)

CrozCountry said:


> How do you measure the inner diameter of the bushings while burnishing? Do you use an Internal Micrometer?


When reaming/burnishing a bushing, it's typically done by passes, not measuring.

Short answer: trial and error.


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## 294037 (Jun 30, 2006)

karpiel said:


> Does anybody know if the diametric tolerance between bushes and stanchions is the same on a FOX 38 and a Zeb ?


The ideal clearance is the same regardless of fork, and generally most major brands are bang on their nominal size, or 0.01-0.02 under. Any variance you might see is still smaller than the amount you want to increase the bushing but so it doesn’t make too much difference. A couple of the smaller brands come with slightly tighter bushings that sometimes need a fractionally smaller tool but usually fox and Rockshox tools are interchangeable 

I will personally vouch for excellent service from Oliver (as do several real life friends) , I emailed him this week and got a fast reply but it did sound like he’s been very busy


----------



## EJ_92606 (Jul 11, 2004)

JohnnyC7 said:


> I will personally vouch for excellent service from Oliver (as do several real life friends) , I emailed him this week and got a fast reply but it did sound like he’s been very busy


You're right, I just heard from Oliver and my tool is ready!


----------



## karpiel (Aug 27, 2010)

JohnnyC7 said:


> The ideal clearance is the same regardless of fork, and generally most major brands are bang on their nominal size, or 0.01-0.02 under. Any variance you might see is still smaller than the amount you want to increase the bushing but so it doesn’t make too much difference. A couple of the smaller brands come with slightly tighter bushings that sometimes need a fractionally smaller tool but usually fox and Rockshox tools are interchangeable
> 
> I will personally vouch for excellent service from Oliver (as do several real life friends) , I emailed him this week and got a fast reply but it did sound like he’s been very busy


Thanks Jonnie, yep I've got the full set of Olivers tools which I've been using since January, very happy with them and have great results.


----------



## CrozCountry (Mar 18, 2011)

EJ_92606 said:


> The burnishing head is properly sized, so there is no measuring of the bushing.


Yes but someone here posted that going beyond a certain point has no benefit. So you do have to stop at certain diameter, even though more passes will increase the diameter.


----------



## EJ_92606 (Jul 11, 2004)

CrozCountry said:


> Yes but someone here posted that going beyond a certain point has no benefit. So you do have to stop at certain diameter, even though more passes will increase the diameter.


All I know about the topic is what I've read in the 40 pages of this thread. Oliver also has a Youtube video demonstrating the process as well.


----------



## digev (Mar 7, 2019)

CrozCountry said:


> How do you measure the inner diameter of the bushings while burnishing? Do you use an Internal Micrometer?


No need to measure and you can’t overdo it! If you move from a +0.07mm to a +0.1mm die it’s just because you still need more clearance probably caused by unfortunate/rare tolerance stack-ups

Because you do it manually at very low speed you can’t do anything wrong! Stop when you’re happy about the result (stanchions sliding freely against/between the bushings) that’s all!


----------



## 294037 (Jun 30, 2006)

CrozCountry said:


> Yes but someone here posted that going beyond a certain point has no benefit. So you do have to stop at certain diameter, even though more passes will increase the diameter.





CrozCountry said:


> Yes but someone here posted that going beyond a certain point has no benefit. So you do have to stop at certain diameter, even though more passes will increase the diameter.


The tool can only make as big as a fraction smaller than its OD, which is usually still way smaller than the point of it being too big would be. Even though each pass will make it slightly bigger, it’s the first one or two that so most of the size increase, from then it’s increasingly small changes. So not so much that going bigger has no benefit, it’s more that you aren’t changing anything any more


----------



## homey2 (Apr 6, 2006)

spokeywheeler said:


> PM Sent


Spokeywheeler I PM'ed you about a 36mm tool in the Bay Area.


----------



## wschruba (Apr 13, 2012)

CrozCountry said:


> Yes but someone here posted that going beyond a certain point has no benefit. So you do have to stop at certain diameter, even though more passes will increase the diameter.


We resize (felt) bushings in pianos as part of regulation/repair--the principle is the same here (even if the tool is different!): in order to make a _large_ difference, you need to use a physically larger burnishing tool. As @JohnnyC7 noted, you get a huge difference in 1-2 passes, but if you _need_ more than that, you need a bigger tool, not more passes.

Maybe the more important thing here is the preparation work: seeing how easily the stanchions drop into the lowers; whether or not there is a marked increase of force just at the top, bottom, left or right. Bushings work best when they are all contributing evenly, so the best course of action is to figure out what needs to be opened up, rather than just hitting all four bushings (but, to be fair, that would probably be 'fine' too). Using a scale to note how easy/hard it is to get the stanchions in individually is what you are looking for here. It's worth noting that, unless you remove the upper bushings, every time you make a pass[es] at the lower bushing, you're going to have to go past the top twice.

You could invest in multi-thousand dollar metrology tools, but the truth here is that for this type of process, in this application: it's unsatisfyingly brutish...just like installing a headset crown race, bending a derailleur hanger back into plane, or using wheel building/truing tools, the use of a burnishing head errs on the side of "subjective", once you've done your work (again, like Johnny noted) and made sure that your stanchions/bushings are sized appropriately for your tool.


----------



## 294037 (Jun 30, 2006)

wschruba said:


> We resize (felt) bushings in pianos as part of regulation/repair--the principle is the same here (even if the tool is different!): in order to make a _large_ difference, you need to use a physically larger burnishing tool. As @JohnnyC7 noted, you get a huge difference in 1-2 passes, but if you _need_ more than that, you need a bigger tool, not more passes.
> 
> Maybe the more important thing here is the preparation work: seeing how easily the stanchions drop into the lowers; whether or not there is a marked increase of force just at the top, bottom, left or right. Bushings work best when they are all contributing evenly, so the best course of action is to figure out what needs to be opened up, rather than just hitting all four bushings (but, to be fair, that would probably be 'fine' too). Using a scale to note how easy/hard it is to get the stanchions in individually is what you are looking for here. It's worth noting that, unless you remove the upper bushings, every time you make a pass[es] at the lower bushing, you're going to have to go past the top twice.
> 
> You could invest in multi-thousand dollar metrology tools, but the truth here is that for this type of process, in this application: it's unsatisfyingly brutish...just like installing a headset crown race, bending a derailleur hanger back into plane, or using wheel building/truing tools, the use of a burnishing head errs on the side of "subjective", once you've done your work (again, like Johnny noted) and made sure that your stanchions/bushings are sized appropriately for your tool.


Yup that nails it...the stack up of all the parts makes it totally impractical to even try and measure. A lot of precision work is done by "feel", even watchmakers working with tiny delicate shafts the require careful clearance for minimum friction hardly measure anything.


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## Grinchy8 (Jul 6, 2021)

I’m looking to rent a 35mm burnisher for a half day in Seattle. PM me if you can help with this!


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## digev (Mar 7, 2019)

Grinchy8 said:


> I’m looking to rent a 35mm burnisher for a half day in Seattle. PM me if you can help with this!


Try the Shock Howse or Butter Suspension I _think_ they can do it for you! If you can’t find a fellow MTB friend ready to help you that is 

Really need to start compiling a list of all the shops able to do it as a service!


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## Grinchy8 (Jul 6, 2021)

digev said:


> Try the Shock Howse or Butter Suspension I _think_ they can do it for you! If you can’t find a fellow MTB friend ready to help you that is
> 
> Really need to start compiling a list of all the shops able to do it as a service!


Shock Howse lists bushing sizing as a service.


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## digev (Mar 7, 2019)

There you go


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## CrozCountry (Mar 18, 2011)

Since you guys are here, isn't it better to measure the force to slide the lowers one stanchion at a time?

I am thinking that when you do both, you are testing the concentricity of the tubes in the bushings rather than the diameter of the bushings. Meaning the bushings can have the +0.07 that you want, but still touch the upper tubes and have a lot of friction. In that case increasing the bushing diameter until there is no contact will make it very large, much more than necessary to have enough clearance for the oil film.


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## karpiel (Aug 27, 2010)

digev said:


> Try the Shock Howse or Butter Suspension I _think_ they can do it for you! If you can’t find a fellow MTB friend ready to help you that is
> 
> Really need to start compiling a list of all the shops able to do it as a service!


Not sure if I'm blatently alowed to promote myself on here but I have the full set of olivers tools and I'm based in Ireland, one forum member has availed of my services and was over the moon with the results, we did give a freshen up with Supergliss lower leg lube which also helped reduce friction. Burnishing tool + Supergliss = a winning combination !


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## digev (Mar 7, 2019)

karpiel said:


> Not sure if I'm blatently alowed to promote myself on here but I have the full set of olivers tools and I'm based in Ireland …


Go for it  I'll add you to the (forthcoming) list


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## karpiel (Aug 27, 2010)

digev said:


> Go for it  I'll add you to the (forthcoming) list


You are a gentleman, thank you.


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## digev (Mar 7, 2019)

Yessssss 













> ERA V2 features new and updated DU bushings with the Radial Lubrication Pockets system RLP, the lower bushing has 3 specifically designed backup channels that allows the oil to flow from the bottom part of the lowers to the upper DU!
> Granting a better lubrication of the stanchion and reducing friction and wear of the system.


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## minisman (Mar 31, 2009)

digev said:


> Yessssss


Interesting, such a simple design change so the oiling port is the backside of the bush, not the wearing side? couldn't we just machine a groove into the back of a new bush for ANY fork, then install it?


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## 294037 (Jun 30, 2006)

minisman said:


> Interesting, such a simple design change so the oiling port is the backside of the bush, not the wearing side? couldn't we just machine a groove into the back of a new bush for ANY fork, then install it?


The ideal condition is a constant film the whole way around the stanchion, so grooves in the face of the bushing aren't that helpful and create points of excess pressure. Grooves like this are (in theory) to help the oil pump back up to the top bushing.

I am purely speculating that the lower bushing might have a thicker wall that allows them to add the groove as lower bushings are typically pretty thin. Not a lot of room to add any useful grooves!


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## digev (Mar 7, 2019)

minisman said:


> Interesting, such a simple design change so the oiling port is the backside of the bush, not the wearing side? couldn't we just machine a groove into the back of a new bush for ANY fork, then install it?


The ideal solution would be to have channels grooved inside the lowers not the bushings, like Fox do with their latest 36/38 but I still think the _regular_ lowers/bushings could be improved/hacked and EXT proved just that. 

On the following pic you clearly see the 2 grooves/channels on the EXT bushing! 



















Option A: the bushings are thick enough to machine oil grooves
Option B: they aren’t and they had to increase the lowers ID to fit thicker bushings (and machine oil grooves)
Option C: ???

I wouldn’t think it’s option B because otherwise they could have re-engineered the lowers and have grooves added directly into the lowers (makes more sense) but it’s just speculation

The thing is … because it happens inside the fork and there’s no way to see or measure the impact/difference we would have to experiment with a glass tube like they did on the video to have a better understanding of how it works 

What we could do is (for 35mm stanchions):


Find some Pyrex glass tube to mimic the lower leg (~ 40cm long x 39mm ID x whatever OD)
Get different 35mm bushings (materials/heights etc … and see if we can machine grooves/channels on the back side)
Seal the tube at the end, fit the _custom_ bushings at the exact same depths, same amount of oil in the lowers and compress/extend the (sealed) stanchion to check what’s going on

Technically, I'd say it’s doable … to at least try! And we could compare the stock vs custom bushings

Who’s up for it? I am 

A question remains: How to install the wiper seal? It think the OD is 45mm (need to think about that) or we use a different seal to do the job just for the sake of trying


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## Sam Handwich (Nov 22, 2018)

Hi all, Anyone in the general Southern Connecticut vicinity have a 36 burnisher I could rent for a day? Or know a shop that would do this for me nearish to me?


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## digev (Mar 7, 2019)

Another way to achieve more oil flow 

Hacking bushings to increase lubrication and reduce friction is definitely doable (it seems)


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## lukam (Nov 5, 2014)

Manitou has also done this on the top bushings of the mattoc 3. The casting has channels behind the top bushings. But they did not implement it on the mezzer. If I remember right Dougal once said that they had a reason not to do it.


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## OneTrustMan (Nov 11, 2017)

So I finally had some time to use my tool for the first time on 2 Lyriks
I build those two forks from a spare fork and parts I got on the second hand market + some new service parts










Using the tool was super easy and it was fun to see the difference it made.
Those 2 fork bushings were not super tight , but the last 30% of travel on both castings got a lot more resistance.
I can't post videos here so I just put a link of my mtb news video uploads
RC 27
ULT 29

Anyway I hope I can test ride the red Lyrik tomorrow. I put it on my ebike to replace the 36 Rhythm.


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## CrozCountry (Mar 18, 2011)

OneTrustMan said:


> Those 2 fork bushings were not super tight , but the last 30% of travel on both castings got a lot more resistance.


This confirms my theory that the difference in sliding friction is from concentricity of the tubes and not diameter of the bushings. Unless the upper tubes were comptly shot, which you would have noticed.


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## OneTrustMan (Nov 11, 2017)

CrozCountry said:


> This confirms my theory that the difference in sliding friction is from concentricity of the tubes and not diameter of the bushings. Unless the upper tubes were comptly shot, which you would have noticed.


Interesting
The casting from the 27 Lyrik ( 2018 and around 2-3k km ) and the almost new red 29er casting ( 2021 and 100km ) had the same higher stiction on the last 30% of tavel. The newer one had overall more resitance as the bushing were almost new.

I also checked for bushing play before and after the burnishing and couldn't feel any.
The red 29er Lyrik is now on my ebike ( 24kg ) and works very well. Put already 100km on it.
The stiction of this fork is now on the same level as my usd fork.


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## mike156 (Jul 10, 2017)

Anybody else have the PTFE liner on the bushing start peeling off after burnishing?

New 2021 Lyrik and it started to delaminate the liner in a couple spots. I used a razor to trim the loose material away. Maybe a millimeter wide at the most. Kind of concerning though as I haven't noticed it do this on the three other forks I've done.


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## wschruba (Apr 13, 2012)

mike156 said:


> Anybody else have the PTFE liner on the bushing start peeling off after burnishing?
> 
> New 2021 Lyrik and it started to delaminate the liner in a couple spots. I used a razor to trim the loose material away. Maybe a millimeter wide at the most. Kind of concerning though as I haven't noticed it do this on the three other forks I've done.


Make sure there is no burr forming on your tool--this happens on shocks with tight pins that may have a sharp edge, too.


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## digev (Mar 7, 2019)

mike156 said:


> Anybody else have the PTFE liner on the bushing start peeling off after burnishing?
> 
> New 2021 Lyrik and it started to delaminate the liner in a couple spots. I used a razor to trim the loose material away. Maybe a millimeter wide at the most. Kind of concerning though as I haven't noticed it do this on the three other forks I've done.


Never  Make sure to lube the die + bushings (before each pass) and twist gently (by gently I mean normal/regular speed) 

Clean tool + clean bushings etc … the obvious stuff

The top ones are usually tighter and might take more time/energy/patience to go through!

I removed some from a brand new Pike few days ago and after measuring everything the upper bushings (short ones) are 1.6mm thick and the bottom ones are 1.4mm thick … that might explain why.





























ID: 35mm
OD: 38mm

Upper bushings

Height: 20mm
Thickness: 1.6mm

Lower bushings

Height: 30mm
Thickness: 1.4mm

It was a doodle to remove with this tool! 










And pressing the new ones should be too (with the depths pre-set from stock)










Waiting for some NDTuned to see if they can be tweaked to improve oil flow (grooves, grinding a flat spot, we’ll see)


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## digev (Mar 7, 2019)

OneTrustMan said:


> Interesting
> The casting from the 27 Lyrik ( 2018 and around 2-3k km ) and the almost new red 29er casting ( 2021 and 100km ) had the same higher stiction on the last 30% of tavel. The newer one had overall more resitance as the bushing were almost new.
> …
> 
> The stiction of this fork is now on the same level as my usd fork.


Putting in the efforts and seeing/feeling the results is the best  happy for you! what’s your USD fork?


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## digev (Mar 7, 2019)

JohnnyC7 said:


> I am purely speculating that the lower bushing might have a thicker wall that allows them to add the groove as lower bushings are typically pretty thin. Not a lot of room to add any useful grooves!


They might have done just that! I measured a 0.2mm difference in thickness between the top and the bottom. So having more material would definitely help creating the groove. Do you know why they are different though?

Edit: it could well be 0.1mm in reality as I don’t have an expensive caliper and 1.4xmm could be seen as 1.4mm on mine etc but there is a difference in thickness!

That’s why I weighed them as well to confirm the difference


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## OneTrustMan (Nov 11, 2017)

digev said:


> The top ones are usually tighter and might take more time/energy/patience to go through!


Yes, I can confirm that it took more effort to go through the upper ones at the first attempt


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## jardo9 (Mar 1, 2020)

Hello. After reading this thread I want to try it on my fork. But I'm wondering what you actualy do to bushings. You basically make it wider when you push through it or by forcing head through it you remove some of the bushing material so it gets wider? I was talking about it with my colleague and he thinks it could be better if heads has some kind of grooves in them something like in picture for better lubricating etc.. But everyone here is making head with smooth finish. So what do you think?


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## wschruba (Apr 13, 2012)

jardo9 said:


> Hello. After reading this thread I want to try it on my fork. But I'm wondering what you actualy do to bushings. You basically make it wider when you push through it or by forcing head through it you remove some of the bushing material so it gets wider? I was talking about it with my colleague and he thinks it could be better if heads has some kind of grooves in them something like in picture for better lubricating etc.. But everyone here is making head with smooth finish. So what do you think?
> 
> View attachment 1960513


Well, what you are describing _would_ work, but it would be called a reaming tool. It is distinct from a burnishing tool in that the function is to _remove_ material rather than force it round (_not _remove material).

In order for it to work as a burnishing tool, great care would need to be taken to have maximum surface area of the circle, and the edges on the channels rounded. I could see your tool being more desirable in a factory setting, where forced lubrication could be used to speed things up on an automated line.


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## jardo9 (Mar 1, 2020)

Yea reamer was inspiration. So when you burnishing you just making bushing more round, is that correct? I think I will make just more heads with smaller increment lets say 0.03 so it is esier to push through.


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## mike156 (Jul 10, 2017)

Interesting in the bushings being different thickness. The upper bushings on the lyriks I've done have definitely all been the tighter bushings.

Hopefully the PTFE peeling a bit doesn't lead to wear or other issues down the road. This fork was the tightest one I've done so far and took a good deal of effort to get it through on the first pass.


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## GH28 (Jun 16, 2014)

Thickness doesn't matter as much as measured ID and OD. If the manufacturer were clever, they would have the casting bore neck down a hair for the lower bushing so it's not doing anything to the upper bushing bore when the lower bushing is installed.


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## digev (Mar 7, 2019)




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## CrozCountry (Mar 18, 2011)

OneTrustMan said:


> Interesting
> The casting from the 27 Lyrik ( 2018 and around 2-3k km ) and the almost new red 29er casting ( 2021 and 100km ) had the same higher stiction on the last 30% of tavel. The newer one had overall more resitance as the bushing were almost new.
> 
> I also checked for bushing play before and after the burnishing and couldn't feel any.
> ...


Did you check the sliding action one leg at a time? This removes the concentricity possibility, but it does still leave the possibility of a tube that is not 100% straight (which can happen in an older fork).


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## OneTrustMan (Nov 11, 2017)

CrozCountry said:


> Did you check the sliding action one leg at a time? This removes the concentricity possibility, but it does still leave the possibility of a tube that is not 100% straight (which can happen in an older fork).


Yes, I did check it them separately. ( after burnishing) 
I think now the reason why there was more stiction on the last bit of travel is because of the tolerances becoming tighter at the crown. 
So you could be right.


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## jscottyk (Jun 3, 2009)

Has anyone been in contact with Oliver recently? I’ve reached out via email and IG but haven’t been able to connect. 


Sent from my iPhone using Tapatalk


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## Danzzz88 (Jun 10, 2020)

CrozCountry said:


> This confirms my theory that the difference in sliding friction is from concentricity of the tubes and not diameter of the bushings. Unless the upper tubes were comptly shot, which you would have noticed.


I had a different theory. When I remove my stanchions from my ZEB I swear to god it looks like the bottom of the stanchions are marginally closer together than at the crown...in other words the stanchions insert into the lowers with an ever so slight V shape being widest near the crown..funny that they look like that and also as said appear to gain friction exponentially as they are pushed further into the fork, especially the last 25%-30% as you say. I think we need to face the fact telescopic forks are inherently a bad design as is the internal combustion engine....but years and years of refinement has got them to an acceptable level. Tolerances need to be just too perfect, diameter, roundness and straightness of stanchions. Roundness and tolerance of bushings...there is just too many areas that need to be ridiculously precise. Now I'm just waiting on the electric motor of Mtb forks...linkage maybe? Burnishing is the mtb definition of polishing a turd.


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## jscottyk (Jun 3, 2009)

jscottyk said:


> Has anyone been in contact with Oliver recently? I’ve reached out via email and IG but haven’t been able to connect.


Connected and order being placed!


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## CrozCountry (Mar 18, 2011)

Danzzz88 said:


> I had a different theory. When I remove my stanchions from my ZEB I swear to god it looks like the bottom of the stanchions are marginally closer together than at the crown...in other words the stanchions insert into the lowers with an ever so slight V shape being widest near the crown..funny that they look like that and also as said appear to gain friction exponentially as they are pushed further into the fork, especially the last 25%-30% as you say. I think we need to face the fact telescopic forks are inherently a bad design as is the internal combustion engine....but years and years of refinement has got them to an acceptable level. Tolerances need to be just too perfect, diameter, roundness and straightness of stanchions. Roundness and tolerance of bushings...there is just too many areas that need to be ridiculously precise. Now I'm just waiting on the electric motor of Mtb forks...linkage maybe? Burnishing is the mtb definition of polishing a turd.


Same theory 😀
There are a few reasons a tube will not be concentric with the bushing. Legs not parallel, legs not straight, and distance between legs not identical to distance between bushings. Same also goes for the lowers, but I suspect most of the issues come from the uppers.

I think it's necessary to check this before enlarging the bushing.


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## jsma09 (Nov 24, 2018)

Has anyone burnished bushings with the seals on? This is on a Fox 36. Current seals are just fine and I don't feel like replacing them just to burnish the bushings, but at the same time I don't want to wait until they're done to see how burnished bushings feel like!


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## digev (Mar 7, 2019)

jsma09 said:


> Has anyone burnished bushings with the seals on? This is on a Fox 36. Current seals are just fine and I don't feel like replacing them just to burnish the bushings, but at the same time I don't want to wait until they're done to see how burnished bushings feel like!


Hi,

You can go ahead and do it, no worries!

Remove the «garter» springs first


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## digev (Mar 7, 2019)

ND Tuned « Bushing Rectifier » 









If you know how it works and how much they sell it for, please let me know (as they never replied to several emails) 

Source: Bushing rectifier 35mm


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## CCS86 (Jan 6, 2020)

jsma09 said:


> Has anyone burnished bushings with the seals on? This is on a Fox 36. Current seals are just fine and I don't feel like replacing them just to burnish the bushings, but at the same time I don't want to wait until they're done to see how burnished bushings feel like!


You can, but it's better to do it with the seals removed. You will get a much better feel for the friction of the bushings without the seals in place. I have a tool that lets you remove the seals without damagng them if you're interested.

Sent from my Pixel 6 using Tapatalk


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## Grinchy8 (Jul 6, 2021)

digev said:


> ND Tuned « Bushing Rectifier »
> 
> 
> 
> ...


You have to contact an ndtune reseller


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## Rick Draper (Dec 1, 2009)

digev said:


> ND Tuned « Bushing Rectifier »
> 
> 
> 
> ...


Not sure how it works, they don't mention any further information on the B2B site either.


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## batboyv (Dec 10, 2021)

CCS86 said:


> You can, but it's better to do it with the seals removed. You will get a much better feel for the friction of the bushings without the seals in place. I have a tool that lets you remove the seals without damagng them if you're interested.
> 
> Sent from my Pixel 6 using Tapatalk


What tool do you use to remove seals without damaging them? It seems like it's a hit or miss with a downhill tire lever.


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## OneTrustMan (Nov 11, 2017)

batboyv said:


> What tool do you use to remove seals without damaging them? It seems like it's a hit or miss with a downhill tire lever.


Use a open jaw wrench. I used a 16mm one with the lower jaw covered with a piece of an old inner tube. Was really easy to remove the seals.


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## CCS86 (Jan 6, 2020)

batboyv said:


> What tool do you use to remove seals without damaging them? It seems like it's a hit or miss with a downhill tire lever.


I designed a tool specifically for it. All contact surfaces are plastic, so it's really safe to use. The wrench method sounds sketchy to me.

Sent from my Pixel 6 using Tapatalk


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## minimusprime (May 26, 2009)

I just did a lower leg service on my 2021/2022 model year fox 36. While I had it apart, I checked the bushing drag of the lowers/csu without the dust wipers installed. It was light years better then the 2018 and 2019 model year 36's that I have burnished the bushings on. It's honestly so good that I will likely not burnish these bushings for a bit and see how they wear in. I wouldn't expect burnishing on these to have the same insane levels of impact that it has on the 18/19 models. Most of the people that have ridden on those particular forks after I worked over the bushings, are completely blown away by the difference.


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## johnsogr (May 31, 2009)

minimusprime said:


> I just did a lower leg service on my 2021/2022 model year fox 36. While I had it apart, I checked the bushing drag of the lowers/csu without the dust wipers installed. It was light years better then the 2018 and 2019 model year 36's that I have burnished the bushings on. It's honestly so good that I will likely not burnish these bushings for a bit and see how they wear in. I wouldn't expect burnishing on these to have the same insane levels of impact that it has on the 18/19 models. Most of the people that have ridden on those particular forks after I worked over the bushings, are completely blown away by the difference.


Glad you brought this up. I just took a brand new Lyrik Select off to burnish, but reading your post, checked how they slid first. They slid right in! I was surprised. Last time I did this with my Pike, Yari, and Mezzer, all had a ton of stiction. Guess I lucked out this time from the factory.


Sent from my iPhone using Tapatalk


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## HollyBoni (Dec 27, 2016)

johnsogr said:


> Glad you brought this up. I just took a brand new Lyrik Select off to burnish, but reading your post, checked how they slid first. They slid right in! I was surprised. Last time I did this with my Pike, Yari, and Mezzer, all had a ton of stiction. Guess I lucked out this time from the factory.
> 
> 
> Sent from my iPhone using Tapatalk


I was about to beg someone to lend me their burnishing tool as well, but when I disassembled my 2021 Pike to my surprise the bushings seemed perfect. The uppers could easily slide in the lowers all the way down with no weight on them at all.


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## digev (Mar 7, 2019)

I hope it becomes the norm so more riders can enjoy the real feeling of a true bump eating fork 

Happy New Year everyone and thanks to all the fellow riders who contributed to this thread so far


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## OneTrustMan (Nov 11, 2017)

HollyBoni said:


> I was about to beg someone to lend me their burnishing tool as well, but when I disassembled my 2021 Pike to my surprise the bushings seemed perfect. The uppers could easily slide in the lowers all the way down with no weight on them at all.


I would do the final test with at least a front hub installed, because that's the state how the lowers will be later on.
The lowers could be bent slightly different with no hub between the legs.
After burnishing my 2 lowers I installed a front wheel and made the slide test again to be extra sure.


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## HollyBoni (Dec 27, 2016)

OneTrustMan said:


> I would do the final test with at least a front hub installed, because that's the state how the lowers will be later on.
> The lowers could be bent slightly different with no hub between the legs.
> After burnishing my 2 lowers I installed a front wheel and made the slide test again to be extra sure.


Tried that as well, basically made no difference. No binding, no extra resistance. Here is a vid (with no hub installed):


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## OneTrustMan (Nov 11, 2017)

HollyBoni said:


> Tried that as well, basically made no difference. No binding, no extra resistance. Here is a vid (with no hub installed):


Well I wrote "it could be" the case.
The lowers, or a hub could be slightly out of tolerance. I had a non boost hub that was acutally 99,3 ish mm instead of 100mm.
And sometimes people report that their wheels don't fit well in the brand new fork that is under the 110mm width.
My Selva is also a tiny bit under 110mm which makes installing the front wheel a bit annoying. But it doesn't seem to affect the fork after all.


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## CrozCountry (Mar 18, 2011)

OneTrustMan said:


> I would do the final test with at least a front hub installed, because that's the state how the lowers will be later on.
> The lowers could be bent slightly different with no hub between the legs.
> After burnishing my 2 lowers I installed a front wheel and made the slide test again to be extra sure.


So if the legs are not parallel when you clamp the wheel, is that a reason to burnish?


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## oab1 (Apr 18, 2018)

I've got a 2021 sid select+, looking to do this to during a lower leg service before bushing play issues arise. 

Anyone have a 35mm tool in southern California they'd rent? Or know of a local suspension service?


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## digev (Mar 7, 2019)

Nothing to do with bushings this time but just a cool video/documentary made by my mate Mathieu about where we ride (south east of France) and the culture about the « French Lines » 

Hopefully you enjoy it


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## GH28 (Jun 16, 2014)

GH28 said:


> Anyone in Socal have a 38mm burnishing tool set I could rent?


Checking again on this one. Or if there are any shops around LA that would perform the service if I brought in a set of Zeb lowers.


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## digev (Mar 7, 2019)

GH28 said:


> Checking again on this one. Or if there are any shops around LA that would perform the service if I brought in a set of Zeb lowers.


Fluid Focus in SanDiego can help you out! If it’s too far you can reach out to «Advanced Dynamics» based in Glendale (not 100% sure about this one)


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## HollyBoni (Dec 27, 2016)

I'm still convinced that something is off with my 2021 Pike Select+. When I gutted it and checked the bushings this is the result I got:





The uppers easily slide in the lowers, same thing with the wheel in and axle tightened. That should mean the bushings are okay, right? However the fork still feels just weird and notchy. It's just not smooth, especially at the beginning of the travel. When I push down on the bars lightly, the fork moves down and comes back up in "sections", not in a smooth motion. Setting sag is basically impossible, I get different results every time. Even if I lower the air pressure a bunch, the sag barely increases, the fork just doesn't want to react properly to me sitting or standing on a bike, it feels like i'm fighting some kind of friction.
It also makes this "sshhh" sound as I compress the fork, here is a recording:






(I'm just pulling the front brake and compressing the fork here)

I'm using RS 0w30 oil currently (want to try Supergliss in the spring and summer), used SRAM butter before, for now I tried using dynamic seal grease with oil in the air chamber. I just installed an Everflow kit so the fork is freshly serviced, but it has been like this since day 1. Everything looks perfectly fine inside the fork. No marks on the bushings or stanchions, nothing weird that I can see.
I don't really have a reference for other forks, just came back to MTB after a few years off, and I never had decent equipment before. I have a friend with a previous gen Pike Select+, his fork feels completely different. His feels more damped, but smoother, and it doesn't make this "ssshhh" noise, and he barely ever services the thing.
Any ideas what could be the issue?  Or is there actually an issue, or i'm just expecting too much?


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## evernorth (Apr 13, 2020)

HollyBoni said:


> I'm still convinced that something is off with my 2021 Pike Select+. When I gutted it and checked the bushings this is the result I got:
> 
> 
> 
> ...


Maybe you have an issue with your damper. A crushed glidering on the rebound piston, or misaligned shims or something like that. Could be something in your damper since you changed and checked everything else. Also excessive noise (especially in comparison with a select+ of your friend) would also point in the direction of the damper.


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## HollyBoni (Dec 27, 2016)

evernorth said:


> Maybe you have an issue with your damper. A crushed glidering on the rebound piston, or misaligned shims or something like that. Could be something in your damper since you changed and checked everything else. Also excessive noise (especially in comparison with a select+ of your friend) would also point in the direction of the damper.


Hmm, didn't think about the damper. It feels smooth when I cycle it by hand but not sure how much that matters. It's going to MST in about 2 weeks so i'll know if there are any issues with it. Also i'll probably just pull the damper without taking apart the fork and see if the noise and friction goes away.
If it's not the damper, it has to be the bushings or the air spring, right? But if it's been the same with two different air springs, i'm guessing that leaves the bushings.

Or maybe I should just send the whole fork to MST...

Edit: Yep, i'm gonna admit defeat and send the whole fork to MST.


----------



## Bike_Tyson (Jun 4, 2021)

Is there anyone (or bike shop) in the St. Louis, MO area that has a bushing tool for a Fox 36? I don't plan to use Fox forks in future builds, but currently have a 36 that I'm going to install a Secus on and would love to smooth the bushings out while I have the lowers dropped. I suffer, as many seem to, from harshness and lack of small bump compliance.

I'd pay for the service, just don't want to buy a tool that I'll likely only use one time.

If this shouldn't be in this thread, I can delete it.


----------



## digev (Mar 7, 2019)

Bike_Tyson said:


> Is there anyone (or bike shop) in the St. Louis, MO area that has a bushing tool for a Fox 36? I don't plan to use Fox forks in future builds, but currently have a 36 that I'm going to install a Secus on and would love to smooth the bushings out while I have the lowers dropped. I suffer, as many seem to, from harshness and lack of small bump compliance.
> 
> I'd pay for the service, just don't want to buy a tool that I'll likely only use one time.
> 
> If this shouldn't be in this thread, I can delete it.


Trail Labs should be able to help you!


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## Bike_Tyson (Jun 4, 2021)

digev said:


> Trail Labs should be able to help you!


Thanks digev, they are definitely my back up plan, but they are in Springfield so I was hoping not to have to have to send it via package if there was something or someone more local. I did use them last year for re-shimming my Ohlins fork, so I agree they are a good option.


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## ARider (Feb 28, 2005)

Anyone heard from ol' Oliver @ Blue Liquid Labs lately?

Ordered some tools, he said they were ready to ship, I paid the man and now crickets for two weeks. 
Sent a few emails with no response.


----------



## johnsogr (May 31, 2009)

I heard from him about 2 weeks ago as well, just mailed him my fork, hope he’s around!


Sent from my iPhone using Tapatalk


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## digev (Mar 7, 2019)

Before/After: mov: IMG_3596.MOV and 1 other file

@notbadsuspension


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## GH28 (Jun 16, 2014)

I'm also waiting to hear back from him about lead times and whatnot. Seems like this keeps happening.


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## The_Bob (Jan 16, 2018)

Did a friend's SID this week. One bushing was so tight I thought I was going to break the lowers trying to get the tool through. Loosened it up nicely after a few passes. Also did my new Pike, which was actually pretty good out of the box


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## piciu256 (Feb 15, 2019)

Does anyone have the 37mm tool in Poland or close, willing to rent?


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## jscottyk (Jun 3, 2009)

Reporting on the burnishing of a new Mezzer Pro. My experience with the Mezzer seems to be unlike some others with this fork. The top bushing in the first let I started working was a BEAST. I mean crazy tight. My memory may not be serving me, but it felt like it took me 15 min to get the tool through one bushing. The lower bushing on the first leg was much more straightforward. Going back up with a second pass was tight but much improved. I ended up doing two more up/down passes. The second leg was a totally different experience. It benefited from the tool but was dramatically easier than the first leg.

Ride test coming up soon.


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## evernorth (Apr 13, 2020)

Made a fork happy today, thought i share it with you guys 









Lyrik pre and post bushing calibration







youtube.com


----------



## ARider (Feb 28, 2005)

evernorth said:


> Made a fork happy today, thought i share it with you guys
> 
> 
> 
> ...


Nice work. 

What is that hub fixture you have in the vice? Something you made?
Looks much easier that mounting a full wheel in there....


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## evernorth (Apr 13, 2020)

ARider said:


> Nice work.
> 
> What is that hub fixture you have in the vice? Something you made?
> Looks much easier that mounting a full wheel in there....


Thanks! 

It's a tool made by Andreani. Its their Fork-Axle support tool for Vices. Cost around 80€ and fits 15x100, 15x110, 20x110 and QR axles.

I quite like it, in the past I have used a cheap hub instead of a whole wheel to check if the bushing are within spec.


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## gatag (May 21, 2015)

Hello suspension gurus, I know it's not the right place for this but don't think it's worth to open a new thread. 

So my new 38 is doing something that's driving me nuts, would like to know your opinions if maybe it's the bushings. Everytime I leave the bike unused (not compressing the fork) for more than 30 minutes and I pull on the handlebars it makes this weird clunk at top out. If I compress it it will not make the noise again have to leave it alone for half an hour and it does clunk just one time unless I leave it alone for another 25-30 minutes or more I already did a lower service and air spring service and no change whatsoever. Can replicate the noise with the fork off the bike so it's not headset or bakes or whatever. Contacted Fox and basically said f*CK off (I'm not in the US and in a country with 0 service centers). 

See video here:
Clunk


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## davec113 (May 31, 2006)

gatag said:


> Hello suspension gurus, I know it's not the right place for this but don't think it's worth to open a new thread.
> 
> So my new 38 is doing something that's driving me nuts, would like to know your opinions if maybe it's the bushings. Everytime I leave the bike unused (not compressing the fork) for more than 30 minutes and I pull on the handlebars it makes this weird clunk at top out. If I compress it it will not make the noise again have to leave it alone for half an hour and it does clunk just one time unless I leave it alone for another 25-30 minutes or more I already did a lower service and air spring service and no change whatsoever. Can replicate the noise with the fork off the bike so it's not headset or bakes or whatever. Contacted Fox and basically said f*CK off (I'm not in the US and in a country with 0 service centers).
> 
> ...


I'd suspect a seal is allowing air to escape from the - spring. Are you losing any pressure over time?


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## davec113 (May 31, 2006)

Just thought I'd chime in on my experience getting my 38 worked on. 

It developed bushing play and I asked Dirt Labs to fix it, they didn't have the 38 bushing tools yet so it got sent to Fox, they repaired the fork which included brand new lowers for no charge and when I got it back the improvement was not subtle! I thought the fork was pretty good before but now it uses full travel much more regularly and I have to run significantly more air and HSC, now I'm going to add another spacer. Finally, Fox's setup recs make sense and now I know the previous forks from both RS and Fox have had issues with bushings. So many people running lower air pressures, no HSC, etc. thinking this is how the fork just is, but now I think most forks come with shitty bushing tolerances out of the box.


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## gatag (May 21, 2015)

davec113 said:


> I'd suspect a seal is allowing air to escape from the - spring. Are you losing any pressure over time?


Not losing pressure initially but yesterday the fork felt EXTREMELY hard, seemed odd to me. Then I pressed the bleeding ports and to my surprise all the air had transfered to the lowers and rushed out through bleed ports. I serviced the air spring and that solved it BUT the noise is still present. Baffled, really.


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## gatag (May 21, 2015)

davec113 said:


> Just thought I'd chime in on my experience getting my 38 worked on.
> 
> It developed bushing play and I asked Dirt Labs to fix it, they didn't have the 38 bushing tools yet so it got sent to Fox, they repaired the fork which included brand new lowers for no charge and when I got it back the improvement was not subtle! I thought the fork was pretty good before but now it uses full travel much more regularly and I have to run significantly more air and HSC, now I'm going to add another spacer. Finally, Fox's setup recs make sense and now I know the previous forks from both RS and Fox have had issues with bushings. So many people running lower air pressures, no HSC, etc. thinking this is how the fork just is, but now I think most forks come with shitty bushing tolerances out of the box.


What exactly are the symptoms of bushing play? Is it just a rocking motion?


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## davec113 (May 31, 2006)

gatag said:


> What exactly are the symptoms of bushing play? Is it just a rocking motion?


You'll hear it, there will be a knocking sound when you hit bumps and it'll feel a bit like a loose headset. 



gatag said:


> Not losing pressure initially but yesterday the fork felt EXTREMELY hard, seemed odd to me. Then I pressed the bleeding ports and to my surprise all the air had transfered to the lowers and rushed out through bleed ports. I serviced the air spring and that solved it BUT the noise is still present. Baffled, really.


I think your air spring must still have a bad seal somewhere.


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## gatag (May 21, 2015)

davec113 said:


> You'll hear it, there will be a knocking sound when you hit bumps and it'll feel a bit like a loose headset.
> 
> 
> 
> I think your air spring must still have a bad seal somewhere.


 I think you are right. I just came back from a spin on my local trails. Had a bad crash because the stanchions sucked down in a very steep part of the trail. Chainring is gone  . Once I got up I realized the fork was sucked down maybe by 7cm, in a fit of rage I yanked it up very hard and heard a hissing sound and it is now again at 170mm but don't trust it. Damn fork


----------



## gatag (May 21, 2015)




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## bad mechanic (Jun 21, 2006)

ARider said:


> Anyone heard from ol' Oliver @ Blue Liquid Labs lately?
> 
> Ordered some tools, he said they were ready to ship, I paid the man and now crickets for two weeks.
> Sent a few emails with no response.


What ended up happening?


----------



## ARider (Feb 28, 2005)

bad mechanic said:


> What ended up happening?


Everything showed up without issue, just took a bit of time.


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## brash (Dec 4, 2018)

gatag said:


> Hello suspension gurus, I know it's not the right place for this but don't think it's worth to open a new thread.
> 
> So my new 38 is doing something that's driving me nuts, would like to know your opinions if maybe it's the bushings. Everytime I leave the bike unused (not compressing the fork) for more than 30 minutes and I pull on the handlebars it makes this weird clunk at top out. If I compress it it will not make the noise again have to leave it alone for half an hour and it does clunk just one time unless I leave it alone for another 25-30 minutes or more I already did a lower service and air spring service and no change whatsoever. Can replicate the noise with the fork off the bike so it's not headset or bakes or whatever. Contacted Fox and basically said f*CK off (I'm not in the US and in a country with 0 service centers).
> 
> ...


I have 2 bikes with 38's, both do it. One burnished, other didn't need it. 

I'm certain it's how they come from the box. I wouldn't worry about it.

I can check another one for you tomorrow at the shop.


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## teK-- (Dec 3, 2011)

davec113 said:


> Just thought I'd chime in on my experience getting my 38 worked on.
> 
> It developed bushing play and I asked Dirt Labs to fix it, they didn't have the 38 bushing tools yet so it got sent to Fox, they repaired the fork which included brand new lowers for no charge and when I got it back the improvement was not subtle! I thought the fork was pretty good before but now it uses full travel much more regularly and I have to run significantly more air and HSC, now I'm going to add another spacer. Finally, Fox's setup recs make sense and now I know the previous forks from both RS and Fox have had issues with bushings. So many people running lower air pressures, no HSC, etc. thinking this is how the fork just is, but now I think most forks come with shitty bushing tolerances out of the box.


This.

I bought the 38s after my 36s kept eating stanchions (even with burnished bushings). Was assured that 38s have much better QC for their bushings.

Couldn't have been more wrong. My 38 bushings were so tight they destroyed a set of stanchions within 5 hours of riding time. Worn down to bare metal...

Fox ended up sorting it out, but it shows how little attention they give to bushing tolerances in new forks.

Now the forks are repaired they feel magnitudes better than when they were new.


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## jsma09 (Nov 24, 2018)

With a burnishing tool head of say +0.07 mm of whatever you stanchion diameter is, how much is the bushing springing back into its original diameter vs permanently deformed? 
Say for a 36.07 mm, will it end up being something like 36.068? or more like 36.04 mm.


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## teK-- (Dec 3, 2011)

jsma09 said:


> With a burnishing tool head of say +0.07 mm of whatever you stanchion diameter is, how much is the bushing springing back into its original diameter vs permanently deformed?
> Say for a 36.07 mm, will it end up being something like 36.068? or more like 36.04 mm.


If I understand correctly the teflon is in a plastic state, so once you push the tool through it should stay permanently deformed. As for how much the metal casing of the bushing opens up and takes up the clerance (and then closes back up to its original size), that is anyone's guess.

Probably worthwhile doing a few passes until you feel the same resistance each time.


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## EJ_92606 (Jul 11, 2004)

teK-- said:


> If I understand correctly the teflon is in a plastic state, so once you push the tool through it should stay permanently deformed. As for how much the metal casing of the bushing opens up and takes up the clerance (and then closes back up to its original size), that is anyone's guess.
> 
> Probably worthwhile doing a few passes until you feel the same resistance each time.


I recall some detailed info on this topic further back in the thread. It seems that the teflon does spring back to some extent.


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## jsma09 (Nov 24, 2018)

It seems like with the manufacturing tolerances of the stanchion OD and bushing ID, if your tool also has a fixed diameter, you don’t have any control over the final clearance achived.

Wouldn’t it be better if you used some of those self-centering locking assembly tools? You could drop it in place starting with a smaller than needed diameter, position it at the bushing height, and then start tightening the nut/nuts that open the ring in a controled manner, applying pressure to the bushing plastic.

Technically you could achieve whatever clearance you’re after, factoring in your actual stanchion OD. The one potential problem I see is that the ring that applies pressure to the bushing is split, would that maybe leave an odd mark on the bushing? You would also have to measure a lot more than using the pilot with the fixed size…


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## Blkdoutindustries (Feb 23, 2020)

jsma09 said:


> It seems like with the manufacturing tolerances of the stanchion OD and bushing ID, if your tool also has a fixed diameter, you don’t have any control over the final clearance achived.
> 
> Wouldn’t it be better if you used some of those self-centering locking assembly tools? You could drop it in place starting with a smaller than needed diameter, position it at the bushing height, and then start tightening the nut/nuts that open the ring in a controled manner, applying pressure to the bushing plastic.
> 
> Technically you could achieve whatever clearance you’re after, factoring in your actual stanchion OD. The one potential problem I see is that the ring that applies pressure to the bushing is split, would that maybe leave an odd mark on the bushing? You would also have to measure a lot more than using the pilot with the fixed size…


I think you are overthinking it, while the tolerances could be a couple thousands different from stanchion to stanchion and the bushing could spring back a little, the biggest improvement comes not from the clearance between bushing and stanchion but the fact that after burnishing the bushing is perfectly round.


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## digev (Mar 7, 2019)

What is the « Ultimate Bushing Package » ?? (according to Rockshox)











VitalMTB:



> Pike, Lyrik, and ZEB Ultimate models all feature longer bushings, 53% longer than prior models. RockShox is calling this the Ultimate Bushing Package. While the Select+ and Select forks do have increased bushing overlap, RockShox does not give up the particulars. Riders can purchase new, Ultimate lowers if they want the Ultimate Bushing Package on their Select, Select+, or Base forks.



BlisterReview:



> The Ultimate-series forks also get a new bushing package, with a 53% longer lower bushing, which RockShox says increases overlap and reduces friction by distributing the load over a greater area and helping to mitigate binding when the fork is being heavily loaded. Other fork trims get the standard bushing package, and upgrading to the Ultimate bushings requires an entire UItimate lower leg casting with the bushings pre-installed.


PinkBike: 



> At the Ultimate level, the bushing length in the lower fork legs has been in creased by 53%. That is said to give better support for the stanchions, reducing friction and distributing the load where the leg and bushing meet. With that in mind, the Ulitmate level bushings are sized and installed at the factory for 2023 forks only, so you will need new lowers for a Select level fork to achieve this upgrade.


RockShox:



> Can I retrofit the Ultimate bushing package on RockShox Select + and Select forks?
> 
> The bushings are sized and installed into the lower leg at the factory. The only way to upgrade the bushing package is to install the MY23 Ultimate lower leg.
> 
> ...


They've noticed they could do better … which is good! But taller bushings = Greater contact area = Greater frictional force 

Fingers crossed they’ve improved QC or else …


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## teK-- (Dec 3, 2011)

digev said:


> What is the « Ultimate Bushing Package » ?? (according to Rockshox)
> 
> 
> Fingers crossed they’ve improved QC or else …


"The bushings are sized and installed into the lower leg at the factory. "

Does this mean they actually burnish them at the factory:? That's gotta be a first!

Maybe other manufacturers can offer "ultimate bushing package too" in that case...


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## gatag (May 21, 2015)

brash said:


> I have 2 bikes with 38's, both do it. One burnished, other didn't need it.
> 
> I'm certain it's how they come from the box. I wouldn't worry about it.
> 
> I can check another one for you tomorrow at the shop.


Really, That's a relief I guess. Please if possible check with the other bike at your shop. Thank you!


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## The_Bob (Jan 16, 2018)

I've taken to applying a bit of slick honey to the bushings with a small paint brush whenever I do a lower leg service. It might be placebo, but my forks feel really smooth since I started doing this. Had a few people ride my bikes and remark on how plush the forks feel.


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## teK-- (Dec 3, 2011)

The_Bob said:


> I've taken to applying a bit of slick honey to the bushings with a small paint brush whenever I do a lower leg service. It might be placebo, but my forks feel really smooth since I started doing this. Had a few people ride my bikes and remark on how plush the forks feel.


Does that feeling diminish before long? I'm guessing the slicko would quickly shear off with use, or be diluted by the oil.

Similar to applying slicko on the wiper seals; it all eventually migrates away from that area or gets absorbed into the oil and foam rings.


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## The_Bob (Jan 16, 2018)

teK-- said:


> Does that feeling diminish before long? I'm guessing the slicko would quickly shear off with use, or be diluted by the oil.
> 
> Similar to applying slicko on the wiper seals; it all eventually migrates away from that area or gets absorbed into the oil and foam rings.


I did my one Pike around 5 riding hours ago and it still feels magic. I'll have a look next time the fork is open to see how much grease is left on the bushings. Like I said, it could all just be in my mind!


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## EJ_92606 (Jul 11, 2004)

I tried it awhile ago and the slick honey ended up in a blob at the bottom of the fork leg and also got sucked up into the damper area and coated the whole damper with it. Fork always feels good after a service...can't say I noticed much difference and I think in the long term it could interfere with the way the oil is supposed to flow.


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## HollyBoni (Dec 27, 2016)

The_Bob said:


> I've taken to applying a bit of slick honey to the bushings with a small paint brush whenever I do a lower leg service. It might be placebo, but my forks feel really smooth since I started doing this. Had a few people ride my bikes and remark on how plush the forks feel.


Hmm, is there even enough clearance between the bushing and the stanchion for grease?
Like Tek said, I think the grease will probably mix with the oil. Like when I tried dynamic seal grease + oil in my air spring... Holy crap, what a freaking mess! Sludge everywhere.


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## gatag (May 21, 2015)

brash said:


> I have 2 bikes with 38's, both do it. One burnished, other didn't need it.
> 
> I'm certain it's how they come from the box. I wouldn't worry about it.
> 
> I can check another one for you tomorrow at the shop.


Hi! Did you checked the other one at the shop? If it's normal for 38s to clunk, then I can let it go and rest my mind lol.

Lmk


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## digev (Mar 7, 2019)

@everflow.suspension posted something really interesting on a story today

It’s about the surface treatment roughness between the 2023 Lyrik stanchions vs 2021 Lyrik stanchions 

The relation between the stanchions and the bushings is pretty obvious as they work in pairs and they impact each other

Let’s start with his story














































Great stuff! Kudos to him for thinking about doing these measurements and sharing the results with everyone 

Now let’s dive into what this means

What are the different parameters of roughness?


Ra: is the average roughness of a surface.

Rz: is the difference between the tallest “peak” and the deepest “valley” in the surface.

(Ra vs Rz is like comparing inches to meters. They are not compatible. Use one or the other not both.)

Rp: Maximum Profile Peak Height, is the distance between the highest point of the profile and the mean line within the evaluation length.

Rv: Maximum Profile Valley Depth, is the distance between the deepest valley of the profile and the mean line within the evaluation length

2021 Lyrik stanchions roughness (brand new)

Ra: 0.227 µm
Rz: 1.795 µm
Rp: 0.612 µm

Rz: 1.794 µm
Rp: 0.612 µm
Rv: 1.183 µm


2023 Lyrik stanchions roughness (brand new)

Ra: 0.429 µm
Rz: 2.951 µm
Rp: 1.129 µm

Rz: 2.951 µm
Rp: 1.129 µm
Rv: 1.831 µm

Facts:

- One can say that average roughness as almost doubled (Ra + 90%) from previous years/models 

- There is a relationship between surface roughness and friction 

What is the ideal surface roughness?

According to Igus:

The ideal range for iglide bushings is …8-16 RMS for linear applications.

8-16 RMS = 0.18-0.36 Ra

According to SKF:

PTFE composite bushings: Ra ≤ 0.4 µm and Rz ≤ 3.0 µm

With the 2023 (Lyric) stanchions they went from 0.23 Ra to 0.43 Ra. So from the lowest recommended value to a bit more than the highest recommended value

Hypothesis:

- It could be good news! There is an « optimum » surface roughness value/range for each application and it has a direct impact on the friction coefficient. They seem to have kept the DLC coating (Diamond-Like Carbon) but have doubled the roughness … after paying attention, trying to refine/improve the new chassis, thorough testing … it was the « optimum » value for the application? when the previous value was the acceptable norm at the time, and maybe an overlooked detail compared to everything else? It’s just a different DLC grade (with different properties) and it was changed to improve durability? Could this change improve the lubrification? (film pressure, load-bearing capacity, etc …)

Conclusion:

- It'd be cool to know if the bushings roughness has been changed as well to get a better picture of these unadvertised modifications (upgrades?) to the 2023 chassis.

- Will this change translate to a tangible difference on the trails? God knows … who would have thought a few micrometers of added clearance and roundness would make (in some cases) that much difference when it comes to the bushings? Guilty 

- Nonetheless it’s pretty exciting to see RS (and others) make changes to the chassis and really start to dig deep into what is the fundamental base of a good suspension fork

Shout out to @everflow.suspension for thinking about measuring all this and sharing the results with us (the riders)! Give him a follow if you don’t already because he’s got a fresh approach about bike suspensions and he likes to test and measure stuff! As we all know by now, if you don’t measure … 

Sources:









Shaft considerations for bearing applications part 2: roughness


In part 2 of the series we discuss shaft roughness and its effect on complex composite bearings.




toolbox.igus.com










Surface Roughness Conversion Chart Tables


Surface Roughness Conversion Charts and Tables, definitions and data. Where: Ra = Roughness, average in micro-meters & micro-inches, RMS = Root Mean Square in micro-inches, CLA = Center Line average in micro-inches



www.engineersedge.com










SKF







www.skf.com







https://journals.sagepub.com/doi/pdf/10.1177/1687814014568500


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## Bafo808 (Feb 6, 2021)

Thank you Digev and all the people that appreciates all those numbers. I'll post also the values I've measured on a fairly used Fox 36, tomorrow I'll try also on my 2year used Lyrik to see if something has flattened.

Fox 36 Kashima
Ra 0.176
Rz 1.621
Rp 0.499
Rv 1.122

Speaking of bushings, the new Lyrik does not only have them taller, but the upper ones also without any vertical slot. Excuse me for this extremely crappy picture, it was late and dark and I was in a hurry!


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## Notthatbryan (Aug 7, 2021)

The roughness measurement for DLC coatings relies mainly on the roughness of the surface it is applied to. 
The good news is that a rougher surface improves adhesion of DLC to an extent. That means the finish should be hold up better.


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## Bafo808 (Feb 6, 2021)

I think that the coating is some sort of hard anodization, DLC is extremely hard (and expensive) while those stanchions can be scratched quite easily


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## teK-- (Dec 3, 2011)

Bafo808 said:


> Thank you Digev and all the people that appreciates all those numbers. I'll post also the values I've measured on a fairly used Fox 36, tomorrow I'll try also on my 2year used Lyrik to see if something has flattened.
> 
> Fox 36 Kashima
> Ra 0.176
> ...


Very nerdy. I love it! Thankyou for sharing this info.

In regards to the non slotted upper bushing they have done this on the Fox 38 as well. 

I can attest that having only the bottom bushing slotted, will still destroy the stanchions if the bushings are too tight.


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## rain164845 (Jul 6, 2008)

Who will clearance bushings for me on a lyrik and a fox 36 in the us?

Sent from my SM-G975U using Tapatalk


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## Bafo808 (Feb 6, 2021)

Measuring my used Lyrik around sag area and bottom out area I found some interesting things.
Sag area 
Ra 0.048 (!!!)
Rz 0.825
Rp 0.125
Rv 0.701

Bottom out area
Ra 0.227
Rz 1.599
Rp 0.487
Rv 1.112

I couldn't believe on how low was the Ra and I recalibrated the tester.
With such a wear I am even more a believer that the stanchions are not DLC coated.

Plus, I have ridden this fork on 150 and 160 travel for almost a year, and when I tried it at 180 there was definitely more stiction. This make me think that a used set of stanchions slides better, but I may be overlooking something else...


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## digev (Mar 7, 2019)

Bafo808 said:


> Measuring my used Lyrik around sag area and bottom out area I found some interesting things.
> Sag area
> Ra 0.048 (!!!)
> Rz 0.825
> ...


You might be right about the coating, according to different sources it’s called 

Fast Black

It’s an epoxy paint? After all, repair kits like Sendhit use an epoxy resin …. and it’s probably more cost efficient


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## Notthatbryan (Aug 7, 2021)

I work with DLC coatings every day. The stanchions don't look DLC coated. The color and finish are not quite right. 
DLC can be done on aluminum but it is much more difficult to do than steel. 

I'd be shocked if they are DLC.


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## digev (Mar 7, 2019)

Notthatbryan said:


> I work with DLC coatings every day. The stanchions don't look DLC coated. The color and finish are not quite right.
> DLC can be done on aluminum but it is much more difficult to do than steel.
> 
> I'd be shocked if they are DLC.


There we go, thanks for confirming


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## Dougal (Jan 23, 2004)

The stanchion polishing effect is real.

I had a mates Pike about 4 years ago that had never used more than half it's travel in the year he'd had it. I fixed and tuned the damper and modified the air-spring, burnished the bushings and fitted it to my own bike. First four hours of riding on it still sucked with a sticky feel that wouldn't go away.
But after those four hours it started working properly and went smooth like it should.


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## Blkdoutindustries (Feb 23, 2020)

rain164845 said:


> Who will clearance bushings for me on a lyrik and a fox 36 in the us?
> 
> Sent from my SM-G975U using Tapatalk


Where are you? I have all the dies from 32 to 38


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## gatag (May 21, 2015)

Blkdoutindustries said:


> Where are you? I have all the dies from 32 to 38


I am interested too, I am about to purchase a fork. Is it possible to send it to you? Can you contact me through PM to discuss the details. Thank you.


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## wiggeywackyo (7 mo ago)

Has anyone done this and seen improvement on a fork that's seen 2-3000 miles on it?


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## GH28 (Jun 16, 2014)

I have no idea how many miles my 38 had on it by the time I did this, but it was a lot, and there was a noticeable improvement.

What I THINK can happen is that the bushings can also come out of round after a lot of use (more fore/aft loading than lateral), and this puts them back to the desired geometry using the small amount of compressibility of the bushing material. No data to back this up, just speculation.


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## teK-- (Dec 3, 2011)

wiggeywackyo said:


> Has anyone done this and seen improvement on a fork that's seen 2-3000 miles on it?


Yeah did this with a fork over 200 moving hours on it.. the stanchions were shot so it was a new csu with the new sized bushings. Felt better than new.


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## teK-- (Dec 3, 2011)

GH28 said:


> I have no idea how many miles my 38 had on it by the time I did this, but it was a lot, and there was a noticeable improvement.
> 
> What I THINK can happen is that the bushings can also come out of round after a lot of use (more fore/aft loading than lateral), and this puts them back to the desired geometry using the small amount of compressibility of the bushing material. No data to back this up, just speculation.


Interesting theory. You might be on right track as mine destroyed a second csu about a year after when it was fitted along with new sized bushes. I'm ocd with my maintenance too.


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## Skel8tor (Dec 8, 2017)

Do you need to remove the dust wipers in order to burnish the bushings? Don't have extra wipers on hand and I've always heard to replace them once removed due to potential damage


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## The_Bob (Jan 16, 2018)

I’ve always just removed the gaiter spring and left the wipers in place. No leaks or damage


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## wiggeywackyo (7 mo ago)

GH28 said:


> I have no idea how many miles my 38 had on it by the time I did this, but it was a lot, and there was a noticeable improvement.
> 
> What I THINK can happen is that the bushings can also come out of round after a lot of use (more fore/aft loading than lateral), and this puts them back to the desired geometry using the small amount of compressibility of the bushing material. No data to back this up, just speculation.


Interesting. So even with naturally "broken in" bushings, there may still be a benefit then. May have to get on this and try it out.


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## silentG (May 18, 2009)

Skel8tor said:


> Do you need to remove the dust wipers in order to burnish the bushings? Don't have extra wipers on hand and I've always heard to replace them once removed due to potential damage


I have the tool that @naturaltalent makes (see https://www.pinkbike.com/buysell/3236867/ for details) and he formed the heads so they slide right through the seals and springs.

Have done two out of my three forks so far and no issues with the seals getting caught by the tool. 

Sample size of one so I can't speak to other tools out there.

Quite happy with the tool, very nicely made and with several forks to do the cost of sending them somewhere for service and burnishing was the same or more than the tool plus time in transit vs being able to do it in my own house.


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## fftfk (Nov 26, 2020)

silentG said:


> I have the tool that @naturaltalent makes (see https://www.pinkbike.com/buysell/3236867/ for details) and he formed the heads so they slide right through the seals and springs.
> 
> Have done two out of my three forks so far and no issues with the seals getting caught by the tool.
> 
> ...


Thanks for the heads up. I just reached out to him.


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## daviduk (Jul 30, 2021)

what i noticed is when checking the stanchions in the fork legs to see if they slide nicely,always fit the front wheel back on as the fork legs are not always perfectly spaced on their own
my fox 36 were loose when sliding one stanchion in on their own but sticky with both,thought hmm,fitted the front wheel and tightened up and then checked again and they dropped quicker than panties on payday.


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## OneTrustMan (Nov 11, 2017)

daviduk said:


> what i noticed is when checking the stanchions in the fork legs to see if they slide nicely,always fit the front wheel back on as the fork legs are not always perfectly spaced on their own
> my fox 36 were loose when sliding one stanchion in on their own but sticky with both,thought hmm,fitted the front wheel and tightened up and then checked again and they dropped quicker than panties on payday.


That's why I always check bushing tightness with a hub installed. 
My Pike Ult was perfect right out of the box. 
No wonder it rides so well.


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## raceservicesuspension (Sep 17, 2016)

Anybody ran their tools through the supposedly "sized from factory" 2023 RS Ultimate bushings? The one Zeb i've had through the shop was as bad as any other...


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## 006_007 (Jan 12, 2004)

silentG said:


> I have the tool that @naturaltalent makes (see https://www.pinkbike.com/buysell/3236867/ for details) and he formed the heads so they slide right through the seals and springs.
> 
> Have done two out of my three forks so far and no issues with the seals getting caught by the tool.
> 
> ...


Yikes - twice the price of Oliver's option.

But I do like it's made in Canada.


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## silentG (May 18, 2009)

I figured that a tool I have in hand is better than a tool I can't get for whatever reason.

Not inexpensive but with several forks on hand in my garage I ran the numbers and the ROI there for me vs sending each fork off for service + burnish makes it break even before I run through the forks I have on hand.


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## fftfk (Nov 26, 2020)

Facebook bought the tool for me. I received a settlement check for FB selling my biometric data right when I was reading this thread so I splurged.


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## bad mechanic (Jun 21, 2006)

fftfk said:


> Facebook bought the tool for me. I received a settlement check for FB selling my biometric data right when I was reading this thread so I splurged.


Facebook did what?


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## fftfk (Nov 26, 2020)

bad mechanic said:


> Facebook did what?


Lol - FB got sued for violating IL biometric data law. I signed up for the class action status expecting get about $.50 but instead got a little less than $400 for it. Here’s a link explaining it - Facebook Biometric Information Privacy Litigation

Always sign up for your class action notices! Most of the time you get very little but every once in a while you can get a nice bit of money.


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## daviduk (Jul 30, 2021)

theres a zucker born every minute


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## sean44 (Dec 10, 2018)

Has anyone ever checked the bushings in the air spring or the damper?


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## raceservicesuspension (Sep 17, 2016)

Kinda in the same ballpark, but I didn't want to start a new thread.

Cornelius hones out the air leg before assembly in this video:






Should we be doing this down the length of our probably out of tolerance legs too? Anybody given it a go yet?

I remember the everflow guy saying he increased his fork travel, and once he hit the unused piece of stanchion he experience a whole bunch of friction since the bushings has basically polished his legs. Well i guess the quad seal on a air piston wouldn't have quite the same effect on the inside of the stanchion, so I guess maybe there's some gains to be made there?


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## hssp (Aug 28, 2007)

The bushings in the air spring are not load bearing to the same extent, and will therefore not have the same impact on overall friction is my take. I think the seals etc are a more significant friction component in the air spring. Cornelius is using pneumatic seals and just polishes the surface lightly before assembly.

I would like to know what you could use to polish the inside of the stanction without ruining the anodizing, though.


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## hssp (Aug 28, 2007)

silentG said:


> I have the tool that @naturaltalent makes (see https://www.pinkbike.com/buysell/3236867/ for details) and he formed the heads so they slide right through the seals and springs.
> 
> Have done two out of my three forks so far and no issues with the seals getting caught by the tool.
> 
> ...


I got a set of these with blocks for 35, 36, 37 and 38mm. I have Mezzer, and guinea pigged mine with the 37mm block. Before it was very bad, but after, I felt I got some play between the bushings I haven't seen before. Anyone who can say if this is a by-product of getting buttery smooth suspension? I got the set to help with friends' forks, but I will not do it unless it is not backfiring on me. The play is very small, but I can feel a vibration in the front wheel once I bounce front wheel off the floor.


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## EdSawyer (Mar 20, 2020)

hssp said:


> I would like to know what you could use to polish the inside of the stanction without ruining the anodizing, though.


Cerium oxide maybe? 

on the bushing work on your Mezzer, how many passes did you make?


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## hssp (Aug 28, 2007)

I twisted and took maybe two times in and out on both! I may have twisted too much? The instructions was that I should get less resistance, but I didn't get it to be too "loose", so I stopped.


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## EdSawyer (Mar 20, 2020)

a couple passes sounds about right. I would think some twisting is required regardless?


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## sstefanov (Sep 18, 2005)

hssp said:


> I got a set of these with blocks for 35, 36, 37 and 38mm. I have Mezzer, and guinea pigged mine with the 37mm block. Before it was very bad, but after, I felt I got some play between the bushings I haven't seen before. Anyone who can say if this is a by-product of getting buttery smooth suspension? I got the set to help with friends' forks, but I will not do it unless it is not backfiring on me. The play is very small, but I can feel a vibration in the front wheel once I bounce front wheel off the floor.


Are the bushing lubed when doing the test (lower legs with oil inside, fork inverted for a while, so they can be properly lubed)? I think it is normal to have a minor play if the bushings are dry and no play if they are lubed. That is how I have my Fox 34 after burnishing.

Stefan


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## hssp (Aug 28, 2007)

I use SuperGliss oil in the lowers. The functionality is ace, and I can barely feel the play. It is just that darn vibration happening when I the wheel bounces off the ground.


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## fftfk (Nov 26, 2020)

hssp said:


> I got a set of these with blocks for 35, 36, 37 and 38mm. I have Mezzer, and guinea pigged mine with the 37mm block. Before it was very bad, but after, I felt I got some play between the bushings I haven't seen before. Anyone who can say if this is a by-product of getting buttery smooth suspension? I got the set to help with friends' forks, but I will not do it unless it is not backfiring on me. The play is very small, but I can feel a vibration in the front wheel once I bounce front wheel off the floor.


I felt the same using the same tool when I first did it. I hung my bike up for storageallowing the oil to lube the bushings and didn’t feel it again. Ifinally got my first ride yesterday and was very happy with the performance.
Not sure which made the bigger improvement though - burnishing the bushings or doing the first lower leg service - but I did think the two together resulted in a big/noticeable improvement.


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## link1896 (Jul 13, 2007)

hssp said:


> I got a set of these with blocks for 35, 36, 37 and 38mm. I have Mezzer, and guinea pigged mine with the 37mm block. Before it was very bad, but after, I felt I got some play between the bushings I haven't seen before. Anyone who can say if this is a by-product of getting buttery smooth suspension? I got the set to help with friends' forks, but I will not do it unless it is not backfiring on me. The play is very small, but I can feel a vibration in the front wheel once I bounce front wheel off the floor.


If you have some quality vernier calipers, but ideally an external micrometer, measure the Mezzer’s stanchion diameter. We are aiming for a burnishing head that’s 0.07 to 0.1mm larger then the stanchions. Fox can’t produce stanchions with consistent diameters, so quite possible the Mezzers are undersized and not 37.00 as well, and so your 37.07 or 37.1mm tool has produced bushings set slightly too large now. 


I always measure stanchions before I burnish, and having the luxury of a lathe I can make my own custom head to suit every situation. 

Will save the data and share from now on.


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## BigBadaBoom (Sep 6, 2020)

Anyone know someone making and shipping these tools in the EU?
Am really interested in buying one with a couple of tool heads..


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## OneTrustMan (Nov 11, 2017)

BigBadaBoom said:


> Anyone know someone making and shipping these tools in the EU?
> Am really interested in buying one with a couple of tool heads..


Does Oliver ( blue liquid labs) not sell anymore? 
Shipping from US to germany via UPS didn't even took 1 week and was 50$ back than.


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## hssp (Aug 28, 2007)

OneTrustMan said:


> Does Oliver ( blue liquid labs) not sell anymore?
> Shipping from US to germany via UPS didn't even took 1 week and was 50$ back than.


He was in the middle of relocating a month ago, so I got a set from Naturtalent @pinkbike for some tools. He was quick.


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## fftfk (Nov 26, 2020)

I reached out to Oliver via his website prior to purchasing from pink bike guy. He said he was in the process of setting up a new shop and would reach out when finished.


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## CrozCountry (Mar 18, 2011)

daviduk said:


> what i noticed is when checking the stanchions in the fork legs to see if they slide nicely,always fit the front wheel back on as the fork legs are not always perfectly spaced on their own
> my fox 36 were loose when sliding one stanchion in on their own but sticky with both,thought hmm,fitted the front wheel and tightened up and then checked again and they dropped quicker than panties on payday.


Yes, that is another confirmation that in the videos the friction difference when sliding the lowers (before and after burnishing) is because of concentricity and not because burnishing makes it smoother.


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## Bearded4Glory (Aug 14, 2021)

Does anyone around the SF Bay Area have the tool and 36mm head I could rent? Happy to pay someone to do it also.


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## SICD Ltd (3 mo ago)

BigBadaBoom said:


> Anyone know someone making and shipping these tools in the EU?
> Am really interested in buying one with a couple of tool heads..


I make and sell resizing tools in Scotland, UK and ship worldwide. Check the link in my signature.

Full kits come in a flight case with custom CNC machined foam inserts to keep everything neat and tidy. I usually carry a couple in stock for quick delivery (although I'm currently out of 35 and 36 mm heads - more coming next week).


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## OneTrustMan (Nov 11, 2017)

SICD Ltd said:


> I make and sell resizing tools in Scotland, UK and ship worldwide. Check the link in my signature.
> 
> Full kits come in a flight case with custom CNC machined foam inserts to keep everything neat and tidy. I usually carry a couple in stock for quick delivery (although I'm currently out of 35 and 36 mm heads - more coming next week).


Are your heads compatible with Oliver's tool? 
What's the threat size?


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## SICD Ltd (3 mo ago)

OneTrustMan said:


> Are your heads compatible with Oliver's tool?
> What's the threat size?


Mine use an M6 cap head screw and a serrated crush washer to attach to the handle with an M12 x 1.0 grub screw to prevent the M6 from backing out. If I'm honest I've not used Oliver's tool personally so I'm not sure if they're compatible however from what I have seen from his tools they probably wouldn't work as a direct replacement.


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## link1896 (Jul 13, 2007)

SICD Ltd said:


> Mine use an M6 cap head screw and a serrated crush washer to attach to the handle with an M12 x 1.0 grub screw to prevent the M6 from backing out. If I'm honest I've not used Oliver's tool personally so I'm not sure if they're compatible however from what I have seen from his tools they probably wouldn't work as a direct replacement.


I’m about to manufacture them here in Australia. There will always be that one person the drops the head into the lowers below the lower bushing. 

I’ve been thinking about a pin between handle and head to stop the head turning, then the m6 bolt doesn’t need to be locked by a grub screw, as someone will undo the m6 bolt with the grub screw not out far enough and mangle threads. Plastic pellet on the tip of the grub screw will last 5 minutes too.


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## SICD Ltd (3 mo ago)

link1896 said:


> I’m about to manufacture them here in Australia. There will always be that one person the drops the head into the lowers below the lower bushing.
> 
> I’ve been thinking about a pin between handle and head to stop the head turning, then the m6 bolt doesn’t need to be locked by a grub screw, as someone will undo the m6 bolt with the grub screw not out far enough and mangle threads. Plastic pellet on the tip of the grub screw will last 5 minutes too.


The M12 screw doesn't lock on the threads so zero chance of damaging them and if the head does come loose you can tighten just by spinning clockwise. I honestly don't think it would be possible to lose the head in your forks unless you were actively trying to.


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## wschruba (Apr 13, 2012)

Agree, non-issue.

Just engrave an arrow on the handle end that says, "turn this way".


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## fftfk (Nov 26, 2020)

wschruba said:


> Agree, non-issue.
> 
> Just engrave an arrow on the handle end that says, "turn this way".


“A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.” - Douglas Adams


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## wschruba (Apr 13, 2012)

While I agree with DA, as well as the popular sayings regarding fools/idiots, at a certain point as a manufacturer of anything, you need to some basic competency.

Since someone can handle unthreading screws/separating a fork should they be using this kind of tool, you have to also assume they can handle, "only turn one way".


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## zooky (Jan 24, 2021)

link1896 said:


> I’m about to manufacture them here in Australia. There will always be that one person the drops the head into the lowers below the lower bushing


Yes please!!


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## BIke N Gear (Sep 27, 2004)

I'm trying to determine what's up with my Fox 38. I have tried a Secus, then did the Smashpot coil conversion. At 220 lbs, I've gone from 55 to 50 to 45 lb springs but still rarely use more than half of my 160mm of travel. The fork has about 1300 miles on it. Can the bushings still be too tight? Today I tried to cycle the fork without the spring, just the damper cartridge and it gets noticeably hard to slide the legs past 100mm. It can be done, but it needs to be forced.


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## The_Bob (Jan 16, 2018)

Could be bushings or alignment of the stanchions. I'd say it is time for a warranty claim


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## digev (Mar 7, 2019)

BIke N Gear said:


> Today I tried to cycle the fork without the spring, just the damper cartridge and it gets noticeably hard to slide the legs past 100mm. It can be done, but it needs to be forced.


Try without the damper too. Then you’ll know if the issue is down to the chassis (it should slide freely)


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## BIke N Gear (Sep 27, 2004)

digev said:


> Try without the damper too. Then you’ll know if the issue is down to the chassis (it should slide freely)


Without the damper, everything slides fine. However, with the damper installed (even without the 40ml of oil) it feels like it hits a wall with about 45mm to go. If I press the bleed button a bunch of air comes out and you can easily push it to full travel. So, it seems to be a buildup of air on the damper side. No idea if this is normal.


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## bobmirko (2 mo ago)

BIke N Gear said:


> I'm trying to determine what's up with my Fox 38. I have tried a Secus, then did the Smashpot coil conversion. At 220 lbs, I've gone from 55 to 50 to 45 lb springs but still rarely use more than half of my 160mm of travel. The fork has about 1300 miles on it. Can the bushings still be too tight? Today I tried to cycle the fork without the spring, just the damper cartridge and it gets noticeably hard to slide the legs past 100mm. It can be done, but it needs to be forced.


 Remove the shrink wrap on the coil spring of the Smashpot in the Zeb and the 38 you will thank me later


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## glano (Apr 12, 2009)

Can anyone post up the dimensions of the 36mm burnishing head?


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## elsinore (Jun 10, 2005)

Has anyone here bought this bushing tool from Pinkbike?



https://www.pinkbike.com/buysell/3236867/


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