# Custom brake adaptor for V-brakes



## xc71 (Dec 24, 2008)

Talked about this in msimmons 24" build Thread.I didn't want to hijack his Tread so starting a new one.This is to allow a 24" wheeled V-brake bike to run a 26" V-brake fork. I just got a great deal a Sid Race Carbon 80mm fork.This will be going on a Scott Spark RC 24.Just received the Cad drawing.


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## Greg WJs (Apr 1, 2005)

In for one of those if the price is right.


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## xc71 (Dec 24, 2008)

He sent me a new design today = lighter weight.


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## TigWorld (Feb 8, 2010)

Excellent. Design looks good. If the price is right it should be a winner. Two possible issues.

Firstly, the brake stud distance on most forks I've seen is 80mm between centers, but I don't think there is a standard as such (this is why brake boosters often have some adjustability built in).

Secondly, different v-brake designs require more or less standoff from the adapter. The XTR linkage type in particular require a fair amount of standoff before the linkage will clear the adapter. See for example the height of the bosses on this adapter I machined up to add v-brakes to an Anthem X frame:


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## LAD (Oct 30, 2009)

Please keep me updated if these become available.


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## xc71 (Dec 24, 2008)

LAD said:


> Please keep me updated if these become available.


For sure.I keep you updated right to the point of when its on the bike & working.


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## msimmons (Jun 14, 2007)

sign me up.


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## xc71 (Dec 24, 2008)

TigWorld said:


> Excellent. Design looks good. If the price is right it should be a winner. Two possible issues.
> 
> Firstly, the brake stud distance on most forks I've seen is 80mm between centers, but I don't think there is a standard as such (this is why brake boosters often have some adjustability built in).
> 
> Secondly, different v-brake designs require more or less standoff from the adapter. The XTR linkage type in particular require a fair amount of standoff before the linkage will clear the adapter. See for example the height of the bosses on this adapter I machined up to add v-brakes to an Anthem X frame:


On your 1st point it won't be an issue as everything seems to be in the 80 - 81mm as you mentioned.V-brakes also have so much adjustment for the pads up & down (the Scott Spark rc & Scales rc have 10mm of pad adjustment) even if the centers are out a couple of mm it won't be an issue.
On your 2nd point - for sure that is a concern.He may machine a cutout step in the area where the hole is that mounts to fork to make it fit a wider variaty of v-brakes.We know with the current design it doesn't need the step to fit the Spark/Scale brakes to a Sid.
The other thing he may do is turn the adaptor around backwards & counter sink the bolts that attach it to the fork.


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## mukow68 (Oct 10, 2007)

Cool. 
Subscribed to see where this project goes...


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## Cary (Dec 29, 2003)

Any updates on this project?


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## xc71 (Dec 24, 2008)

I was suppose to get this months ago, but he has gotten very busy on his CNC machine. Says he'll have this to me soon. I'll post pics as soon as I get it.


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## Mike Sinkoski (Oct 26, 2008)

Hope you get that adapter, the kids love equiptment that really works. I made a v-brake adapter for my sons 24 hotrock and fitted a old Rockshox Judy that has the Englund/Total Air cartridges so its super adjustable for his weight. The fork is lots lighter and has more travel and it can actually be compressed by the kids!:thumbsup:


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## xc71 (Dec 24, 2008)

Just got the 1st one made to test fit and function.It looks great and this one weighed 113 grams.The clearance between the 8m hex bolt that holds the adaptor to the fork is very tight, so I can see going to a countersunk style bolt or adding more material to the bottom section that the posts thread intther than that the fit, hole locations, where the pads ended in the Vbrake arms is all excellent.I've just ordered some Ti 8M countersunk bolts, should be here in approx. 2 weeks and I'll update again.I had my son do about a dozen nose wheels ( stoppies) with me watching the front brakes/adaptor, every looked really solid.


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## mukow68 (Oct 10, 2007)

Looks very nice! 
I think an 8mm buttonhead allen or torx bolt would work fine for clearance.
Any idea as to cost?


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## xc71 (Dec 24, 2008)

In this case a button head allen bolt would work fine. However, to appeal to a wide range of v-brake arm designs, a counter sunk allen bolt would give even more clearance.
I don't have to pay for this one, so not sure on price yet.What do you think is a fair price for this.The block of aluminum is around $20.00 then 2 1/2 to 3 hours on the CNC machine @ $75.00 per hour. I know he is not going to charge anywhere near full retail. I'm thinking around half of that, maybe even less.


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## mukow68 (Oct 10, 2007)

Hmmm...
I think a _fair_ price would be the material cost($20) + the cost of manufacture(~$200) + whatever makes it worth your while to make it happen.

That being said, I think the unit price would have to come down to about $40-50/ea. to make it a viable option for most folks. Not sure how your shop charges, but I would imagine that to bring the cost down, you would have to commit to a relatively large order to bring the material and manufacturing costs down, or consider some design tweaking to reduce the amount of CNC needed.

It is a nice piece of work though; I like it!


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## Mike Sinkoski (Oct 26, 2008)

WOW, that looks really good! That Sid is definately top notch in terms of performance for a kid. I also used countersunk bolts on my homeade adapter for clearance from the brake pad mounting boss, but even then yours has more clearance with the hex bolt than mine. Excellent execution with the adapter. Let me know what kind of price you guys can really do. Maybe enough interest on this forum for a "group buy" order.


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## xc71 (Dec 24, 2008)

Thanks, I've got real little ripper on my hands going up & downhill.This was an amazing upgrade with adjustable compression & rebound damping & the dual air.Was also approx. 400 grams lighter than the Spinner Grind fork.


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## xc71 (Dec 24, 2008)

Updated with countersunk bolts.Lots of brake arm clearance now.On the next version he is going to remove material in the arch - probably just make it thinner to take the weight under 100 grams.


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## TigWorld (Feb 8, 2010)

Looking good. Its probably far beefier than what it needs to be. All that CNC work on a big lump of alu seems seriously wasteful. Laser cut from 8mm alu plate and then using Marzocchi brake studs would make them very quick and cheap to make. Properly laid out you'd get a lot of these in a sheet. The zoke studs would also give all the clearance you'd need:


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## Mike Sinkoski (Oct 26, 2008)

TigWorld said:


> Looking good. Its probably far beefier than what it needs to be. All that CNC work on a big lump of alu seems seriously wasteful. Laser cut from 8mm alu plate and then using Marzocchi brake studs would make them very quick and cheap to make. Properly laid out you'd get a lot of these in a sheet. The zoke studs would also give all the clearance you'd need:
> 
> I agee, mine is .165 or about 4mm of 6061 T-6 aluminum for the arch--the width is more critical than the thickness in the arch as the force it handles is the spreading load between the two brake arms, the area where my brake studs attach to the adapter is .330 or about 8 mm and thats just for clearance for the brake arm and to secure the spring anchor. The distance from the relocated brake stud to the adapter mount holes(old brake stud) is so close that the bending forces don't justify any additional material thickness. However, I concede that while mine as thin as they are, will stop my son by providing all the braking power his tires will allow before skidding with even my weight on it, stress fatigue may become a issue-depends how long he will ride this set-up. I would still like to see a cheap, functional adapter on the market whatever the manufacturing process


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## Cary (Dec 29, 2003)

I would definitely want one if it were available at a reasonable price. Right now my fork tuning options for my son's bike are limited to one or two springs and no dampening.


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## xc71 (Dec 24, 2008)

Thanks for the comments guys.Next version will have alot less material. He has been looking at water jetting a bunch up on one sheet then finishing it off on the CNC machine.
I'm not sure I would be comfortable going down to 8mm in the lower section between the countersunk bolt & the brake posts where all the load is on the adaptor.For XC it might be okay, but my son is downhilling at places like Silverstar, SunPeaks,etc. These places have huge braking bumps everywhere, and some are really high speed coming into corners.My sons speed is at a good adult interm. pace, so I'm sure you could see my concern. Not sure when I'll have the next version, but will get pics up as soon as I get it.


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## TigWorld (Feb 8, 2010)

You can take dimensions / material thicknesses from the Mavic 700c adapter as a bit of a guide.


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## ricerockt (Jan 24, 2007)

Just picked up a Scott Spark Jr for my 8 yr old and was looking to upgrade the fork and am looking for a v-brake adapter for 26" forks. Did this adapter ever go into production? If not, does anyone know of a good alternative? I have seen the Mavic 700C to 26" adapter, but nothing for 26" to 24".


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## TwoTone (Jul 5, 2011)

Maybe I missed it, who's making these for you? I'd actually like to get adapters to put v-brakes on my son's 20inch front and rear.


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## xc71 (Dec 24, 2008)

Hey guys, looks like I'm also going to be needing another one of these as my Daughter just moved up to a Scott Contessa 24". My buddy that made my first one got a contract that ties up his CNC machine 5 days a week.I'm going to bug him again this week to water jet 8 or 10 up on a sheet then finish them up on the CNC machine.I will get back to you.


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## ridemtn (Aug 25, 2009)

I'm still interested in one as well if the price was manageable. 
Nice work!


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## ricerockt (Jan 24, 2007)

Sounds good! As long as the price is reasonable, you can count me in


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## khaotom (Mar 14, 2011)

Can this be used on a rigid BMX fork with no brake post?


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## xc71 (Dec 24, 2008)

khaotom said:


> Can this be used on a rigid BMX fork with no brake post?


I'm not up on BMX forks, but I'm pretty sure this won't work.


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## xc71 (Dec 24, 2008)

xc71 said:


> Hey guys, looks like I'm also going to be needing another one of these as my Daughter just moved up to a Scott Contessa 24". My buddy that made my first one got a contract that ties up his CNC machine 5 days a week.I'm going to bug him again this week to water jet 8 or 10 up on a sheet then finish them up on the CNC machine.I will get back to you.


Okay, I talked to my buddy and he is really busy on his CNC machine but is going to try and get 8 - 10 of these done hopefully in September.


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## RideOnG (Feb 25, 2007)

I've got a Spark JR 24 i'm trying to upgrade, i could use one or two of these.
Please let me know if your serious.
thanks
Ride On


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## xc71 (Dec 24, 2008)

RideOnG said:


> I've got a Spark JR 24 i'm trying to upgrade, i could use one or two of these.
> Please let me know if your serious.
> thanks
> Ride On


Definitely serious, as I need another one of these for my daughters Contessa 24". Its just getting my buddy to find enough time to make them.I'm still trying to get him to have these done in September.


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## xc71 (Dec 24, 2008)

I'm sorry to say guys that buddy has pulled the plug on these adaptors. The price he got to water jet these several up on one sheet and then finish them up on his CNC machine is very expensive. Can't see anyone paying big bucks for these.


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## schuster_md (May 18, 2007)

If any of you guys is still interested in getting a custom V-brake adapter, I suggest you to email Dan from Homebrewed Components <[email protected]>. He made custom CNC parts for me before and did an amazing job.

Good luck,

Andres:thumbsup:


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## mhkang (Nov 1, 2008)

schuster_md said:


> If any of you guys is still interested in getting a custom V-brake adapter, I suggest you to email Dan from Homebrewed Components <[email protected]>. He made custom CNC parts for me before and did an amazing job.
> 
> Good luck,
> 
> Andres:thumbsup:


about how much was the brake adapter?
you can PM the info or email at markhkang at yahoo.thx


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## schuster_md (May 18, 2007)

mhkang said:


> about how much was the brake adapter?
> you can PM the info or email at markhkang at yahoo.thx


I didn't order an adapter, I got a custom spider for a cannondale hollowgram crankset. So I thought he would be a good alternative to order a CNC cutted adapter. I think I paid around U$150 for the spider as it was a lot of work. I'm not sure how much would he charge for this work.

Best,

AS


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## SRALPH (Jun 27, 2008)

US$150 for a spider? That's the problem with small runs of custom machining - a large amount of fixed cost regardless of how many or few you punch out.


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## fastpath (Aug 27, 2004)

Dredging this thread up from the past. I ordered a pair of these Vbrake "extenders" from Ebay. I hope they work. They are 3.5mm too short ideally for a 26"(559) to 24"(507) conversion but I'm hoping to make up for that with the adjustment slots in the Vbrake.

https://www.ebay.com/itm/Bike-V-Bra...112964041941?_trksid=p2385738.m4383.l4275.c10


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## nepbug (Sep 3, 2004)

fastpath said:


> Dredging this thread up from the past. I ordered a pair of these Vbrake "extenders" from Ebay. I hope they work. They are 3.5mm too short ideally for a 26"(559) to 24"(507) conversion but I'm hoping to make up for that with the adjustment slots in the Vbrake.
> 
> https://www.ebay.com/itm/Bike-V-Bra...112964041941?_trksid=p2385738.m4383.l4275.c10
> View attachment 1198067


Interesting, make sure you come back and update this thread once you get them in hand and try them out.


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## fastpath (Aug 27, 2004)

Well, I hit a small snag. Because the adapters are not offset. The back of the brakes hit the adapter. Now, I haven't given up. But I'll need to find some vbrakes where the back of the arm is completely flush. Normally, the pad holder sticks out behind. Something like the TRP CX9 or CX8.4 seems to have the pad slots clear the back.


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## fastpath (Aug 27, 2004)

I did manage to get this to work. Ordered a set of litepro long arm vBrakes from Aliexpress.
It's still not ideal because the pads hit the arms and reduce the clearance. A 2.125 tire barely fits through the arms which makes removing the wheel a bit of a pain. Wider tires would have to be deflated.



nepbug said:


> Interesting, make sure you come back and update this thread once you get them in hand and try them out.


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