# Chainline tolerances??? Is 3.5mm too much?



## Gritter (Dec 21, 2010)

My front chainring is riding at 51mm chainline, while the Alfine 11 (with dished cog) is sitting at 47.5mm. Is 3.5mm going to be a problem? Ideally, I'd want it to match perfectly, but I'm wondering how far off from perfect does it start to be annoying (make noise, hinder efficiency, derail, etc.)? 

I know Alfine's specs say it's actually 46.8mm chainline, but I carefully measured the dished Nexus cog's center exactly 20mm from the Lock Nut, or inside face of drive-side track-end. (67.5 - 20 = 47.5mm)

I can't bring in my front chainring at all, on my 73mm wide BB, without completely changing out the crankset for something capable of a 47.5mm chainline - I'm trying desperately to avoid doing that. 

I can't put spacers under the rear cog, because of the split-ring retainer construction. I'm thinking... Dish my rear wheel and offset the hub? No, there's no room for that, and I don't see any spacers to rearrange on the axle. :madman:

Anybody running an IGH with an imperfect chainline? Any ideas to improve without getting a new crankset?


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## fokof (Apr 24, 2006)

Some chainrings have an "offset" to the external part, can be as much as 2mm , where brand names are written , have you tried to put yours in the Middle ring and switched around your chainring ?

Maybe it's not possible on your setup , maybe worth a try .....


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## Gritter (Dec 21, 2010)

fokof said:


> Some chainrings have an "offset" to the external part, can be as much as 2mm , where brand names are written , have you tried to put yours in the Middle ring and switched around your chainring ?
> 
> Maybe it's not possible on your setup , maybe worth a try .....


No. I should mention it's a single ring crankset - Profile Racing with Imperial 33t chainring. I chose it for the "infinitely variable" chainline, but with my 73mm BB and 6" spindle, it's only infinitely adjustable from 51mm and greater.


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## hunter006 (Jan 20, 2012)

FWIW, pictures of your chainring & BB would probably help. Usually when it comes to moving the chainring in, you have a few options:
1) New crank
2) Sometimes you can mount the chainring on the inside of the spider, not out. Mount chainring on inside of spider, use BB spacers to move drive side crank arm out if it's too far in. Can cause Z angle issues.
3) Small alignment issues - flip the chainring around; my Surly chainring can move ~1mm if I face it backwards.

I'd say 3.5mm is doable, but it's going to start getting noisy. I found 2mm to be about the limit of accuracy that I found acceptable on my old Surly Steamroller. You'll have two primary sources of noise - where it engages the cog, and where it engages the chainring. If it's on a bike with really long stays it won't matter as much as a bike with shorter stays, e.g. Extracycle. vs. track bike.


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## rifraf (Dec 22, 2012)

There are commercial spacers available to go between your front chain-ring and your crank.
I couldn't be bothered finding them and used spring-washers. I utilise a single 39T chain-ring on a FC7701 dura-ace crankset with 109.5 bottom bracket. Depending on your setup you may need longer chain-ring bolts. From memory my Dualdrive needed a 45mm chainline.


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## -jes (Feb 6, 2011)

Trying to guess what crank setup you've gone with.

Q and A: Which Spindle do I need? | Profile Racing

Looking at the Profile website I am guessing you'e using the external bottom bracket which at 17.0 and 10.7 mm is quite wide.

Maybe try a bb with a lower width bearing cups and with a range of spacers for chain line adjustment.
Example of a possible option below

Products Bb Euro Bb 1 DMR Bikes

I'me also running a single ring bmx setup but with a 68 mm bb shell, spanish bb and a 5 5/8" spindle with just the bearing cap spacers and chainring spacer, chainline is fine with a dished sprocket.

Hope that helps


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## Gritter (Dec 21, 2010)

-jes said:


> Trying to guess what crank setup you've gone with.
> 
> Q and A: Which Spindle do I need? | Profile Racing
> 
> ...


I use a 6" spindle (necessary for my 73mm BB shell and my "fatties fit fine" chainstays), and internal bearings (narrowest "Q" factor), with imperial 33t sprocket (that uses a bushing to reduce the imperial down to the 19mm spindle - which adds about 1.5mm to my chainline).

Sweet. Unfortunately, my BB shell is 73mm (to clear the wide chainstays on a Surly Ogre "Fatties Fit Fine". If my chainstays were narrower, I'd "face" the BB shell all the way down to 68mm, but as it sits now, the crank arms and chain wheel don't have much room to play with.

The external bottom bracket is quite wide, but that's not my deal. I'm running the internal BB for the "narrowest Q possible", which is going to be 5mm wider than a frame with a 68mm BB, no matter what.

Now, I do have another frame with 68mm BB, and would be able to get a 48mm chainline easily, but that stupid bike has vertical dropouts, so I'd lose the clean lines of not running a dangly chain tensioner (derailleur looking thingie).

I threw a chain on there, just to see, and when I eyeball down the length of it, it SEEMS really straight. I also didn't feel/hear any inappropriate sounds coming from the drivetrain, so I'm going to run it with 3.5mm-off chainline, and see if it drives me crazy. (I'm pretty obsessive compulsive about these things (if you couldn't already tell), so it probably will, but I don't want to use different cranks unless I absolutely have to. Thanks for everyone's help.


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## -jes (Feb 6, 2011)

Try a non dished rear sprocket.


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## rifraf (Dec 22, 2012)

Sheldons usually my first port of call.
His chainline page is: All About Bicycle Chainline
He agrees with my above solution as one way:
"Chainring Spacers
For a single chainring, you can add spacers between the chainring and the crank spider.

If your chainring is mounted on the outside of the spider, you can move it to the right this way. If it's mounted on the inside of the spider, you can move it to the left as shown.

This uses the same 10 mm I.D. spacers normally used on rear hub axles.

Suitable spacers are available in 1, 2, and 3 mm thickness. You may need to use longer "double" stack bolts, especially for the 3 mm size."


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## Andy R (Nov 26, 2008)

-jes said:


> Try a non dished rear sprocket.


Which will make the problem worse........


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## Gritter (Dec 21, 2010)

Andy R said:


> Which will make the problem worse........


Thank you.


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## -jes (Feb 6, 2011)

Andy R said:


> Which will make the problem worse........


Why ? unless he's already running the dished rear sprocket outboard/reversed to the standard orientation, perhaps I am missing something ?

I had a similiar issue running a 83 mm spindle Race Face Atlas crankset on a 73 mm bb shell which despite 6 mm of chain line adjustment plus 83-73 adaptors gave a slightly noisy chainline on my Alfine 11.
So swopped the rear sprocket around to give a better chainline but found the chain rubbed on the cassette joint arm.
The solution was a non dished sprocket.

Could you also flip the chainring reducers so the 1.5 mm sits between the crank anfd the chainring, then space the the chainring ro crankarm bolt, sure I've seen specific washers for this.
See the red bits in the picture in post 5 of the link below.

Cassette hub advice...Chainline

The photo shows the set up with a dished sprocket, sorry the best one I have of this build showing the sprocket.


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## Gritter (Dec 21, 2010)

47.5mm chainline on my Alfine is using the Nexus dished cog, with the dishing aimed outboard. A non-dished cog, or flipping it the other way is going in the opposite direction that I need.

The cassette joint arm and rubber bellows rubbed on your chain (with the dished sprocket), because your "vertical dropout non-turn washers" have your cassette joint arm aimed up towards your seat-stays. Even though cable routing might be more favorable in your situation that way, clearance is not ideal. I've seen people BEND they're cassette-joint-arms to gain a smidgen of clearance, or use zip-ties to pull the arm over to the right, away from the chain.

It looks like you've fashioned a custom non-turn chain-tug on your rig, so changing the angle of attack would be like starting over from the beginning. I just ordered the Civia non-turn chain-tugs for track ends, which will essentially do the same thing, but orient the cassette-joint-arm horizontally:










When the cassette joint arm is more parallel to the ground (running along the chain-stay, using different non-turn washers), there's no chain/cassette-joint-arm/bellows interference. The cassette-joint-arm and bellows will be located in the empty space between the upper and lower run of the chain, and have LOADS of space that way.

Pointing the cassette-joint-arm more towards the 3 o'clock position (along the chain stay) makes for plenty of clearance and no interference from the chain.

I can't flip my front chainring because of the way it uses a bolt to attach to the right crank arm. It looks ever so slightly dished, but "inboard", meaning if I flipped the front chainring, it would increase my chainline to 53mm or so.

I'm just running it at 51mm front and 47.5mm rear, and it seems fine. I guess 3.5mm is nothing for an flexible 8 speed chain, and I don't notice it at all. Believe me, if I could feel/hear it, it would drive me batty until I fixed it, but it seems to be working pretty well, so I'm just going to leave it.

If it bothers me in the future, I will just have to find myself a frame with a 68mm BB shell, which would fix all my "issues" and end up "perfect".

(This is all because I want to run Profile cranks - without a spider. Profile makes a spider that moves the chainring inboard, but I don't want to buy anything else if I don't absolutely have to, but it is an option)


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## rifraf (Dec 22, 2012)

Sorry, I missed where you said you were using a belt and assumed you were using a chain. My bad

I'm tired and I've just gone back to try to spot your mentioning the belt.
I found:


Gritter said:


> Sweet. Unfortunately, my BB shell is 73mm (to clear the wide chainstays on a Surly Ogre "Fatties Fit Fine". If my chainstays were narrower, I'd "face" the BB shell all the way down to 68mm, but as it sits now, the crank arms and chain wheel don't have much room to play with.
> .


Your Ogre has a belt?
Has your frame been customised with a seatstay splitter?
Its been a long day and my head hurts? :eekster:
Whats the haps?:madman:


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## Gritter (Dec 21, 2010)

rifraf said:


> Sorry, I missed where you said you were using a belt and assumed you were using a chain. My bad
> 
> I'm tired and I've just gone back to try to spot your mentioning the belt.
> I found:
> ...


I never said I was running a belt, and didn't mean to imply it. The picture (with the belt on anything but an Ogre) was merely to portray the Civia non-turn tensioners. I gleeped that picture from "ecovelo.info" as the watermark shows. .

I doubt I would ever run a belt on a bicycle. Especially after reading how proper belt tension puts too much pressure on bearings and other issues. I've never heard of "beltline" issues, since the few Gates Belt components available now are all meant to work together.


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## rifraf (Dec 22, 2012)

Gritter said:


> I never said I was running a belt, and didn't mean to imply it.
> I.


Hi Gritter
No worries, I'm a little light on sleep today.
Assuming 3mm spacers are available whats unwelcome about spacers
between your crank spiders and chainring?
Like I said, they worked fine for my dura-ace cranks and sram dual-drive.
My next build is going to be an Ogre. I have my Rohloff, B17 saddle and Thorn cranks so far
and am watching the Ogre build threads and Rohloff chainline threads to make sure I dont miss anything. I have yet to find which square tapered BB will best work and offer me my needed 54mm chainline.
Where did you source your Ogre frame?
Cheers


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## Gritter (Dec 21, 2010)

rifraf said:


> Assuming 3mm spacers are available whats unwelcome about spacers
> between your crank spiders and chainring?
> Cheers


I don't have a spider on my Imperial chainwheel that bolts directly to my crank arm, with no spider. The 1.5mm and 3mm spacers I have can ONLY go between the BB and the Sproket, pushing the chainline further outward.



rifraf said:


> Where did you source your Ogre frame?
> Cheers


Universal Cycles with the VIP15 percent off discount (no tax)- dropped shipped straight from Surly in Minneapolis, box appeared to be sealed from Taiwan.


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## rifraf (Dec 22, 2012)

Gritter said:


> I don't have a spider on my Imperial chainwheel that bolts directly to my crank arm, with no spider. The 1.5mm and 3mm spacers I have can ONLY go between the BB and the Sproket, pushing the chainline further outward. [/QUOTE
> 
> 
> 
> ...


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## rifraf (Dec 22, 2012)

Gritter said:


> Universal Cycles with the VIP15 percent off discount (no tax)- dropped shipped straight from Surly in Minneapolis, box appeared to be sealed from Taiwan.


UPS quote made it uneconomic to do business with Universal Cycles for me here in Australia.
I will say their responses to my inquires were super fast and detailed. I was very impressed and had UPS been a little less hungry would have been ordering in a heartbeat confident in purchasing from a store with such great customer service. 
I dealt with Schmitty who brought me up to date very quickly with available options and was exceedingly prompt with all correspondence.
Heres a big thumbs up for your suggestion of Universal Cycles Gritter:thumbsup:


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## -jes (Feb 6, 2011)

Ok Gritter understood, apologies Andy R for missing the info.

Good tip regarding the Civia chain tug, may be useful on the new frame.


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## Gritter (Dec 21, 2010)

-jes said:


> Good tip regarding the Civia chain tug, may be useful on the new frame.


They're nice, but the non-turn steel plate is only on the drive side. This also makes the drive side twice as thick. I like how they don't imprint divots into your track forkends, the way Shimano non-turn washers do, but the left side gets in the way of Surly's trailer "Yolk", so I might not be able to use them. Or maybe I'll just find a shorter bolt, yeah...



rifraf said:


> Heres a big thumbs up for your suggestion of Universal Cycles Gritter:thumbsup:


That's unfortunate that you're too far for Universal. They pretty much get all my business, they make it easy, and have just about everything under the sun on their site. I like the wishlist part of their efficient cart system, and when you order over three hundred bucks, the discount is on par with market value. Schmitty is great. He's helped me out a lot.

TreeFart Bikes is also good. Respect.

3.5mm difference in my chainline is fine with the flexy 8 speed chain. In case anyone else wants to run Alfine dished-out with Profile cranks on a 73mm BB shell, using an Imperial chainwheel w/19mm spindle bushing and no spider.


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## komekomegaijin (Nov 9, 2008)

Hi Gritter. I'm running an Alfine with the standard sprocket, a standard Shimano 32 tooth middle ring on XT cranks with a 9 speed chain (I think). My chainline is about 3mm off. At first I was worried about that difference but now it's about 3 years down the track and I've never thought about it since. It's never been an issue for me.


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## john_dalhart (Nov 6, 2009)

> Try a non dished rear sprocket.





> Which will make the problem worse.


Well then, there's always Sturmey's deep dish cogs in 17, 18 & 19T. Std. three-tab interface, 1/8 chain, but I have no idea if they'd clear the Shimano 11 otherwise.


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