# Biker-friendly machinists?



## iamkeith (Feb 5, 2010)

Apologies if this is the wrong place to post this question, but I figured somebody here would have a suggestion.

I need to have someone machine for me a one-off adapter to facilitate the use of modern 51mm IS rear disk brackets on a frame with older 22mm Hayes-style direct-mount holes.

Hope used to make the exact piece I need, and it looked like the images below. I can't find one though, so I need to have one made from scratch. But, since I don't have an actual example available for measurement, I need to find a machinist who knows enough about disk brake mouting dimensional standards to figure it out. Honestly, it doesn't even matter if it ends up looking different - it just needs to work. (Someone who understands the standards could even make a piece that skips straight to the 74mm post-mounts, and eliminate one entire bracket.)

Obviously, it needs to be somewhat cost effective too, which is why it would be nice to find someone who isn't inventing the wheel for the first time.

Thanks for any suggestions.

Example of the piece I need made:














The bike I'm trying to fit:


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## 1 cog frog (Dec 21, 2004)

*Interested*

PM sent.

frog


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## pvd (Jan 4, 2006)

Why don't you just call Hope. I'm sure they've got a few boxes of those stacked in some corner.

Anyway, all machinists are bike friendly. You pay them their rate and they will make whatever you like.


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## jgerhardt (Aug 31, 2009)

pvd said:


> Anyway, all machinists are bike friendly. You pay them their rate and they will make whatever you like.


Pete, I have seen this before in architecture. Because we "Love" the profession we are supposed to do our job for half of what we would normally charge. Of course architects are a bunch of pussies who would do anything to get a job. I would hope machinests have a higher standard.


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## smudge (Jan 12, 2004)

This could get ugly...I agree with you guys that people should get paid their rate, full stop. I'll spare you all my foaming rant about the slack ass bro culture in the bike industry that paved the way to the expectation that you're not worth what you charge.

To the OP, there's a **** ton of those adapters out in the world. It might take a while, but if you stay at it, you'll find one.


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## iamkeith (Feb 5, 2010)

Jeesh, guys. By "biker friendly," I meant someone who regularly machines actual _bicycle parts_, so that they might already be familiar with the dimensional standards for brake mounting holes, and how to locate them relative to the axle of the wheel. You know... so I don't end up with an adapter with holes that are the right distance apart, but that doesn't work with any known caliper. I didn't mean that I wanted to find someone who would do it for free. I thought I made that pretty clear in the way I worded my question, but perhaps not.

I live in a small town and, even if I can find a local machinist willing to do the job, I don't want to have to explain to him how a disk brake works or what tollerances are critical. Partly, because I don't know myself. So I thought it would make sense to seek out someone who did.

By the way, I'm an architect myself, in practice for almost 27 years now. But there's a reason I don't design many hospitals. It's not because I couldn't do it - it's becasue there would be a learning curve that no responsible client would want to pay for. In other words, they'd likely seek out a specialist.

Don't be so sensitive.


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## sbitw (Sep 16, 2005)

Like this? Hayes Adapter - OEM Rear -22mm Caliper 6 " Dis | Buy Online | ChainReactionCycles.com
Or this? Amazon.com: A2Z AD-PMR Rear Disc Brake Adaptor, Hayes 22m to 51m IS: Sports & Outdoors


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## stuntnuts (Dec 7, 2010)

iamkeith said:


> I live in a small town and, even if I can find a local machinist willing to do the job, I don't want to have to explain to him how a disk brake works or what tollerances are critical. Partly, because I don't know myself. So I thought it would make sense to seek out someone who did.


It's your responsibility, as the product designer to work out all the details. The machinist simply makes the part off of a print that you provide.


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## iamkeith (Feb 5, 2010)

sbitw said:


> Like this? Hayes Adapter - OEM Rear -22mm Caliper 6 " Dis | Buy Online | ChainReactionCycles.com
> Or this? Amazon.com: A2Z AD-PMR Rear Disc Brake Adaptor, Hayes 22m to 51m IS: Sports & Outdoors


Thanks for the suggestions but, darn it, they won't work. I actually already bought the first one, and it wasn't right (It's for going the other direction - mounting an old 22mm hayes caliper on a modern frame with IS tabs.) The later, a2z one, is intended for seat stay applications instead of chainstay applications like mine, and puts the holes at the wrong angle.



pvd said:


> Why don't you just call Hope. I'm sure they've got a few boxes of those stacked in some corner.


Alas, I tried this too, to no avail. From searching threads on the forum, it sounds like others with the same dilema have struck out previously.



smudge said:


> To the OP, there's a **** ton of those adapters out in the world. It might take a while, but if you stay at it, you'll find one.


I'd hoped so too, but finally gave up. I've watched ebay for a few years and struck out. Again, living in an area with a sparse population doesn't help my odds. And right now I've got the bike apart and was hoping to get it back together for a spring trip. So that's why I finally gave up, and was looking for, AND WILLING TO PAY, a machinist.

Thanks for all the suggestions though. I didn't really expect anyone to take time to acutally look for something. I was just looking for a name of someone capable. Sounds like I've got my man though, and one-cog-frog can help me out.


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## iamkeith (Feb 5, 2010)

stuntnuts said:


> It's your responsibility, as the product designer to work out all the details. The machinist simply makes the part off of a print that you provide.


Man, either you frame builders get a lot of shitty clients that have made you hyper-sensitive, or I must really not be able to communicate. The whole entire point was that I was looking for, AND WILLING TO PAY, a machinist who knows enough about bikes that he/she would be capable of actually _being_ the product designer. I just wanted to say: "This is what I've got, and this is what I need in the end. Do your thing and get me from A to B."

Nonetheless, I appreciate the advice. I guess it may come down to me having to learn the standards myself, and then give someone some drawings. I just thought there might be some specialists out there.


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## sbitw (Sep 16, 2005)

One more suggestion while I'm still slacking off at work. Have you tried the ugly, flexy looking adapter (B&S Rear Parallel Mount Adapter) that Toronto Cycles sells? Torontocycles Disc Brake Adapters, Caliper Adapters, b&s adapters


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## jgerhardt (Aug 31, 2009)

iamkeith said:


> ...By the way, I'm an architect myself, in practice for almost 27 years now...


Me to, though only for 10 years. On top of that I also worked as a draftsmen for machine shop as well as other various crap. Many times I would get some random part I had to make drawings for that would then get fabricated. A part like that could take a couple of hours just to draw up alone. Then add on actual fabrication and that little part could start to get pretty darn expensive. In the end you might just be better off buying a new frame (I heard there is a couple of guys in these forums that make pretty nice custom full suspension frames...)


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## iamkeith (Feb 5, 2010)

sbitw said:


> One more suggestion while I'm still slacking off at work. Have you tried the ugly, flexy looking adapter (B&S Rear Parallel Mount Adapter) that Toronto Cycles sells? Torontocycles Disc Brake Adapters, Caliper Adapters, b&s adapters


Yea, that one's for a bike with holes located on the chainstay too. Thanks so much once again, but I wouldn't knock yourself out on this challenge. Seems like my bike is a pretty odd duck.

(Wish I didn't like it so much and it wasn't still in such good shape. Eventually I WILL need a replacement, but not quite yet...)


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## DWF (Jan 12, 2004)

I'm a "machinist."* I make my all my own product. If I told you how many times I've quoted jobs for bike parts at a rate that falls just this >< short of negative economy only to have them recoil in shock at my price...well, Frank Lloyd Wright would roll over in his grave, rise up as Liberace, and design you a sequin castle.


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## sonic reducer (Apr 12, 2010)

maybe not totally what you wanted to hear, but possibly you could try to build one yourself? not being snide just a suggestion. consider it an exercise for your architectural skills. looks like some 1/4xwhatever angle aluminum, a drill, hacksaw, and a file would be all you would need. you could use some thin aluminum angle as a template to get the hole locations, and a combination of the old hayes brakes, a wheel with rotor in the frame, and new IS caliper for the positioning. some slotting of the frame holes would probably be ok, and could even help on getting the caliper aligned on the rotor.
I don't think you would like the price that a machinist would charge you to design and build a custom part like that. might be worth more than the frame in the end if it is old enough to accept those brakes.


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## iamkeith (Feb 5, 2010)

sonic reducer said:


> maybe not totally what you wanted to hear, but possibly you could try to build one yourself?


Not the worst sidea, by any means.


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## Blaster1200 (Feb 20, 2004)

sonic reducer said:


> maybe not totally what you wanted to hear, but possibly you could try to build one yourself? not being snide just a suggestion. consider it an exercise for your architectural skills. looks like some 1/4xwhatever angle aluminum, a drill, hacksaw, and a file would be all you would need. you could use some thin aluminum angle as a template to get the hole locations, and a combination of the old hayes brakes, a wheel with rotor in the frame, and new IS caliper for the positioning. some slotting of the frame holes would probably be ok, and could even help on getting the caliper aligned on the rotor.
> I don't think you would like the price that a machinist would charge you to design and build a custom part like that. might be worth more than the frame in the end if it is old enough to accept those brakes.


I once actually did just as you described.

And then six years later I found what I did with that old 22mm Hayes caliper I swore that I had at the time I needed it. I still have that damn thing.


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## Blaster1200 (Feb 20, 2004)

What??? I hope clear, concise communication isn't a requirement of an architect.

By the way, have you thought of using Google? There are a fair number of sources for the mount you're looking for, regardless if it's chainstay or seatstay mounting. You may also find the dimensions, should you decided to make your own or have one made. You just have to look. :thumbsup:



iamkeith said:


> Thanks for the suggestions but, darn it, they won't work. I actually already bought the first one, and it wasn't right (It's for going the other direction - mounting an old 22mm hayes caliper on a modern frame with IS tabs.) The later, a2z one, is intended for seat stay applications *instead of chainstay applications like mine*, and puts the holes at the wrong angle.





iamkeith said:


> The bike I'm trying to fit:
> View attachment 675779


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## shirk (Mar 24, 2004)

I agree with most that if you look hard enough you'll find one already made.

If you want to ask a "bike friendly" machinist to make one try North Shore Billet in Whistler. North Shore Billet


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## iamkeith (Feb 5, 2010)

Blaster1200 said:


> What??? I hope clear, concise communication isn't a requirement of an architect.
> 
> By the way, have you thought of using Google? There are a fair number of sources for the mount you're looking for. :thumbsup:


Sorry. I'm getting tired. I never expected this to turn into such a discussion. I clearly transposed the terms "chain stay" and "seat stay" in my hasty reply. Either way, the bracket that was suggested mounts on a CHAIN STAY, and will not work with my bike, which, as you noticed, has the mount on the SEAT STAY:









I've spent countless hours on google, which is how I found images of the discontinued bracket that I need. Not to be glib, because I truly do appreciate all the ideas and input from everyone, but if you do happen to see what I need available somewhere on the web, PLEASE let me know! I'd be greatly indebted.


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## j-ro (Feb 21, 2009)

With one of dwf's fung shoeys all you would need to do is take a small block of AL and and existing disc adaptor that everyone has about 30 of kicking around on the shop floor and make 4 holes.
two to bolt to the frame and two to bolt the adaptor to.

I'm thinking its a saturday afternoon type project. A wide tip stinky black sharpie to 'anodize' it and you could be tearing up the trails on sunday morning.

Looks like a piece 3/8 x 1"x 3 ish should do you fine.

A drill, a 6mm tap and pilot drill, a clamp, a centering punch and a couple of bandaids should be about all you will need to finish the job.


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## Francis Buxton (Apr 2, 2004)

www.a2zcomponents.com

Adapter #AD-PMR.

This is it, no? Almost looks like they still make it.


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## pvd (Jan 4, 2006)

iamkeith said:


> By "biker friendly," I meant someone who regularly machines actual _bicycle parts_, so that they might already be familiar with the dimensional standards for brake mounting holes, and how to locate them relative to the axle of the wheel. You know... so I don't end up with an adapter with holes that are the right distance apart, but that doesn't work with any known caliper. I didn't mean that I wanted to find someone who would do it for free.


That's not the machinists job. You give them a drawing with dimentions, tolerences, and other specifications and they make it. It sounds like you want a mechanical engineer and a machinist. Essentially, a $6k single part.

Did you call Hope on the phone? How about Hayes. ON THE PHONE?

Hope Technical: +44 (0) 1282 818413
Hayes Support: 1.888.MTN.DISC, (1.888.686.3472)


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## iamkeith (Feb 5, 2010)

Francis Buxton said:


> www.a2zcomponents.com
> 
> Adapter #AD-PMR.
> 
> This is it, no? Almost looks like they still make it.


Unfortuantely that one puts the holes at an odd angle. Appears tor work on the chainstay in some cases, but not my bike. Here it is in use:


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## iamkeith (Feb 5, 2010)

pvd said:


> Did you call Hope on the phone? How about Hayes. ON THE PHONE?
> Hope Technical: +44 (0) 1282 818413
> Hayes Support: 1.888.MTN.DISC, (1.888.686.3472)


Thanks for the numbers, but they were actually very responsive and nice through through email, so I didn't see a need to bug them by phone. Got this:

_"Hi, we used to make those years ago. We unfortunately haven't had any for a very long time, and to be honest I wouldn't think any dealers would have any either. Very sorry we can't help with this one."_



pvd said:


> That's not the machinists job. You give them a drawing with dimentions, tolerences, and other specifications and they make it. It sounds like you want a mechanical engineer and a machinist. Essentially, a $6k single part.


Yeah, it's becoming clear that I'll just need to study up and do a drawing myself. In retrospect I probably should have asked the question differently. Given the crazy number of different adapters out there, for all sorts of odd applications, even on newer bikes, I'd just hoped that there might somene who did these types of projects often enough to say "Yea, done it many times - I know exactly what you need." And I thought that you builders might know of someone like that, but clearly they don't exist.


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## BobH. (Sep 13, 2011)

Well heck, you woke me up, now you got my attention. I'm an old retired toolmaker and a bit of a crank. If I wanted someone to machine that bracket I would have to do some homework first. I would fab a bracket out wood for test fit. Almost right is not good enough. Oh, before you fab the bracket, make sure the wheel is in correct position. Then I would make a demensioned drawing of it and I would specify what the material for the bracket would be. If I were making it for myself, I would consider extruded aluminum angle. You can assign the specification. As I'm a cranky old machinist, I can tell you that I'm not a mind reader. After you put a diamond earring in a sow's ear, remember it is still a sow'w ear.

BobH.


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## Live Wire (Aug 27, 2007)

You are seriously overthinking this.
Like SR said in post #15, this is a super easy part to fab. Any framebuilder could do this, no drawing needed. A disk tab ($5-10), a flat plate bolted to the frame ($1), cut the tab to fit the plate and weld/braze ($30-40)...done. Paint it yourself w/a rattlecan.


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## skogan (Jan 12, 2004)

Doesn't even need to get that involved, just needs a piece of 1/8" by 1 1/2" angle, mild steel or aluminum to make a bracket. Electric drill, hack saw, file and scribe are all the tools you need. Install your wheel with rotor and get a rough idea where the caliper needs to be on the bracket. Remove material from the bracket with a hacksaw and file so caliper body can sit flush. Make sure you have left enough material for the bolt holes. Hold caliper and bracket together in the position you want and scribe your four bolt hole locations. Drill your holes, remove excess material if you want and try it out.


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## Stevoo (Mar 9, 2007)

Done a number of similar brake brackets ghetto style. All were unusual geometry, weird and one off. I just use some sheet metal bits and drill a pair of holes in each. Bolt one to the frame and the other on the caliper which is clamped to the rotor in the desired position. Mark with a pencil and tin snip them close. I tack the two pieces together when all is lined up and VIOLA! a perfect template of what you need. The holes are exactly where you need them. Then it is off to the mill where I machine up the final piece out of whatever material you may want to use for the day.

Then polish, paint, blast, ano or whatever finish is desired.


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## HomeGrownSS (Jan 18, 2006)

a few years ago i got the actual 22mm caliper from hayes! works quite well, no adapter necessary.


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## iamkeith (Feb 5, 2010)

OK... If any of you are still following the thread, I followed your collective advice and attempted to create my own fabrication drawing, that any machinist should be able to follow. (Or that maybe I could even use myself, with the help of a few good tools. Seems like a 1 1/2 x 1 1/2 x 1/4 aluminum angle works well enough.) But I have one question, that you guys can probably answer:

From what I could figure out, it seems like the critical thing I need to achieve when providing 51mm IS mounting holes is a "triangle"of dimensions, all located relative to the rear axle. But it also seems like as long as I hit those dimensions, then the mounting holes could be located at whatever angle I want. The "triangle" can simply rotate around the axle as needed.

The first image below is what I came up with. I made the axis of the mounting holes _parallel_ to the seat stay, because it seems like it would be easiest to fabricate (ie.: "machinist-friendly"  )

But the second image shows alternate ways that I _could_ have done it, that seem like they would also work in theory. Am I missing something? Is there any reason NOT to make the holes parallel to the seat stay?! Or more to the point, why are all bikes not like this? Is braking torque more likely to bend the tab if it's taller? Does rotating the brake caliper more rearward than necessary make it vulnerable to damage or make the bike feel weighted funny? I'm still fairly new to disk brakes, and I've just never looked at this so closley before.

Anyway, thanks again for all the advice.


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## Blaster1200 (Feb 20, 2004)

That's shaped a lot like the Woodman adapter.


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## BobH. (Sep 13, 2011)

[But the second image shows alternate ways that I _could_ have done it, that seem like they would also work in theory. Am I missing something? Is there any reason NOT to make the holes parallel to the seat stay?! Or more to the point, why are all bikes not like this? Is braking torque more likely to bend the tab if it's taller? Does rotating the brake caliper more rearward than necessary make it vulnerable to damage or make the bike feel weighted funny? I'm still fairly new to disk brakes, and I've just never looked at this so closley before.

Anyway, thanks again for all the advice.

View attachment 676584


View attachment 676585
[/QUOTE]

keith,

You have got the basic idea, pad location is controlled by disc diameter. So, the axle (the center of the disc) is a major lmount location factor. YA DID GOOD!

BobH.


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## iamkeith (Feb 5, 2010)

Blaster1200 said:


> That's shaped a lot like the Woodman adapter.


Dang! That's another one I'd heard of, but not seen a picture of or found for sale anywhere - but it DOES look like it might work! Thanks for the tip. Will keep looking!

If it does work, I guess it answers my previous question, too. It looks like they chose to rotate the brake rearword simply in order to avoid conflicts between the screw locations.


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## customfab (Jun 8, 2008)

pvd said:


> That's not the machinists job. You give them a drawing with dimentions, tolerences, and other specifications and they make it. It sounds like you want a mechanical engineer and a machinist. Essentially, a $6k single part.


There are plenty of "machinists" that can do a simple design AND machine a part like that.


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## bsieb (Aug 23, 2003)

iamkeith- you could saw that shape out of a piece of aluminum angle with a jewelers saw, drill a few holes...


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## Jasontamu (May 14, 2009)

Does any one have the old HAYES chainstay mount or the A2Z AD-PMR mount for sale????

I would like to buy one of these:

*AD-PMR:*

















*Hayes chainstay 22mm mount:*









-J


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## p2rider426 (Nov 4, 2012)

I'm an ME student at SJSU who likes to play around on milling machines on weekends. If only you were closer I wouldn't mind trying to take a crack at it.


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