# U-Brake: replacement options?



## islander (Jan 21, 2004)

Thought I'd ask here since this forum likely sees more ubrakes than the Brake Forum guys (hopefully Mods won't move it).

I have an old MTB (1990 Rocky Mtn) with rear ubrake studs on the seatstays. Would like to replace the stock caliper as it's now pushing 20yrs old and I want to use this bike in remote places where brake failure is not an option.

The trouble I'm finding is today's u-brakes all seem to be bmx rim specific (ie >26mm wide). I want to run narrower rims than this. 

So, who make a mtb compatable u-brake today ??

My first choice would be a NOS XT u-brake....but have all but given up trying to find one of those...

Thanks for any advice you can send my way.


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## bushpig (Nov 26, 2005)

Is your current brake having problems? The U brake design is pretty good. I haven't heard much in the way of failure. I'd buy a spare and bring it with you.


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## Plusti (Apr 22, 2008)

*Ebay.*

Hello there,

I'm no expert but I'm pretty sure Ebay is going to become your new best friend! We all have had trouble sourcing parts that are no longer in production. Perhaps someone will chime in if they know if U-brakes are still made for MTB's?

Jason


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## cegrover (Oct 17, 2004)

As far as I know, used or NOS are your choices. You can use either a u-brake or a rollercam, which is harder to find and generally more expensive, but preferred by some.

If you're concerned about the location due to mud collection and your frame is steel, you can have cant-/v-brake bosses welded on. Of course, you'd need a hanger if you used cantis, but you could use one that attaches at the seat post binder. Generally, though, most us find chainstay-mounted brakes to work fine for most situations. Plus, they're cool and vintage! :thumbsup:


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## hairstream (Apr 20, 2008)

Unless you're using it for actual braking, the Campy u-brake is purdy.


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## Rumpfy (Dec 21, 2003)

A very clean new (near new?) XT U-Brake auction closed about a week ago. They pop up all the time and aren't generally too expensive. They're relatively easy to set up and have great stopping power. 

I have a beat XT U-Brake and it still works great.


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## WTB-rider (Jul 25, 2004)

cegrover said:


> If you're concerned about the location due to mud collection and your frame is steel, you can have cant-/v-brake bosses welded on. Of course, you'd need a hanger if you used cantis, but you could use one that attaches at the seat post binder. Generally, though, most us find chainstay-mounted brakes to work fine for most situations. Plus, they're cool and vintage! :thumbsup:


His frame has u-brake studs on the seatstays...I agree with you on the chainstay mount though. No rear rim brake I've ever used works as well as the chainstay mounted Speedmaster rollercam on my Potts.


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## Bokchoicowboy (Aug 7, 2007)

You want to get even more obscure partswise, you could try to find some of those old Moots mounts that allow you to clamp on brakes anywhere on your seat or chain stays..


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## islander (Jan 21, 2004)

Thanks for the tips and quick replies guys! I'll share a bit in case others search for same in future.

There's two Deore XT u-brakes BR-M731 and BR-M733, the latter comes with a booster plate to help with stay flexing. The fixing bolt uses and allen head, like canti's today.

The sub-XT ubrake MT-??? has a socket type bolt head. When I removed mine, the bolts looked really long (30-40mm) and aren't threaded for initial mm's. hate these bolts cause a) they're obscure, b) I need to bring more trailside tools. I'm going to try Magura hydro rim brake bolts (40mm, flat allen head) to see if they can serve as spares. 

V-brake booster plates don't have same drilling pattern as u-brake plates. 

Retro Content: Gorilla Brake Beefer was an old school brake booster than came in a u-brake version. it appear this booster came with mounting hardware too (which I covet!).

In the end, I really want a ubrake that uses v-brake style pads, has conventional fastening hardware for use with metric allen keys, works with 24mm rims, and has clearance for full-warp fenders....but there I go dreaming again..


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## girlonbike (Apr 24, 2008)

Fenders?! Then today is your lucky day. You don't need no stinkin' brakes! Yank those brakes out and just go fixie.


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## mainlyfats (Oct 1, 2005)

XT U-Brakes come up on eBay all the time - NOS ones too.

I bought a set of Revenge brakes for one of my bikes - purportedly the best available these days and pretty spendy. 

I'll say this, the collector prices are worth it for NOS Shimano U Brakes. Simple, bomb-proof and powerful.


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## stan4bikes (May 24, 2006)

Another possible option out of the blue...how about DiaCompe 987's? I really know nothing about them, just happen to have a pair.


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## Rumpfy (Dec 21, 2003)

stan4bikes said:


> Another possible option out of the blue...how about DiaCompe 987's? I really know nothing about them


I'd start by checking to see if they can used on U-Brake mounts.


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## WTB-rider (Jul 25, 2004)

stan4bikes said:


> Another possible option out of the blue...how about DiaCompe 987's? I really know nothing about them, just happen to have a pair.


The _987_ is a cantilever brake, the _997_ is a BMX u-brake.


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## stan4bikes (May 24, 2006)

WTB-rider said:


> The _987_ is a cantilever brake, the _997_ is a BMX u-brake.


oops..I meant 997's. I'm sure "R" was happy at my mistake so he could take a quick shot at me


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## KDXdog (Mar 15, 2007)

I have an old U-brake with the bolts on my Fat, a Scott SE U-brake (seatstays) on my Scott, and a black XT U-brake (allen) WITH a Gorilla booster!

I ran the XT in place of the Scott SE, as the SE demanded way too much cleaning to get it to work right. I put the SE back on a while back, I don't use the bike so much anymore.

Enough blabbing: I would find an old XT. Bulletproof. The only thing I can see failing would be a spring.


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## Rumpfy (Dec 21, 2003)

WTB-rider said:


> No rear rim brake I've ever used works as well as the chainstay mounted Speedmaster rollercam on my Potts.


Not true. Marginal power at best. Complicated to set up and a pain to keep them tuned. Hard to find or find parts for. Ugly, ugly brakes. Potts suck too.


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## C Miller (Aug 28, 2008)

*XT U brake*

I picked up a NOS XT U-Brake for my Ritchey Ascent off Ebay last week, about 42.00 shipped. Was searching today and saw a couple of XT U-brakes, used, for little or nothing as well as NOS pads for them. As mentioned they are there and at pretty reasonable prices.


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## WTB-rider (Jul 25, 2004)

Rumpfy said:


> Not true. Marginal power at best. Complicated to set up and a pain to keep them tuned. Hard to find or find parts for. Ugly, ugly brakes. Potts suck too.


Ahhh, go play with your Slingshot sonny


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## WTB-rider (Jul 25, 2004)

stan4bikes said:


> oops..I meant 997's. I'm sure "R" was happy at my mistake so he could take a quick shot at me


He's miffed he can't use a rollercam on his Slingsnot :lol:


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## ckevlar (Feb 9, 2005)

The xt ubrake is a choice selection. Works well in either version. If it is going on the seatstays I'd get the one with the booster. Its not needed on the chainstays as their pretty stiff already. If you want to do it on the cheap. Look for Dia-compe 990 brakes. Decent power. A little more flex in the arms then the ultra stiff xt u. Only problem is it uses a stud type brake pad. Now Diatech, Dia-compes taiwanese cousin makes a brake called the Hombre. It uses standard threaded pads but the springs are exposed to the elements. The 990's springs are enclosed. Check flatlandfuel:
http://www.flatlandfuel.com/index.asp?PageAction=VIEWCATS&Category=6
Modern ubrakes are mostly used on flatland bikes. If they use any at all. Be sure if you pick something modern that its not front brake specific. Sometimes this makes a difference. 
Check them out. But I'd wait for an xt myself.

Oh and the Campagnolo Eucild Ubrakes arent too bad. Pretty stiff and strong. But the stock pads suck big time. Had a pair of these on a former trials bike and they worked great. They just weight twice what others do.


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## Rumpfy (Dec 21, 2003)

stan4bikes said:


> oops..I meant 997's. I'm sure "R" was happy at my mistake so he could take a quick shot at me


Hell ya I was!


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## Rumpfy (Dec 21, 2003)

WTB-rider said:


> Ahhh, go play with your Slingshot sonny


My attempts at down playing wonderful bikes and wonderful brakes so that more people don't look for them and prices don't skyrocket more than they're already at = fail


I roller cam'ed Slingshot would be the coolest thing EVER!


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## captain8track (Sep 26, 2008)

I've heard something on retrobike that u can flip maguras upside down somehow, and that in that way. would fit u-brake fittings ???


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## WTB-rider (Jul 25, 2004)

Rumpfy said:


> My attempts at down playing wonderful bikes and wonderful brakes so that more people don't look for them and prices don't skyrocket more than they're already at = fail
> 
> 
> I roller cam'ed Slingshot would be the coolest thing EVER!


Yeah, it flew right over my head, (probably because I don't have a collection or plans of starting one) I figured I was getting a V-R-C onion busting. Trying to convince the wife I need an updated Potts but I'm not making much headway :nonod:

I could swear Martin Stenger had a u-brake on one of the earliest Slingshots but I'm probably wrong.


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## Fatmikeynyc (Jun 20, 2005)

*Gorilla U-brake Beefers*



islander said:


> Retro Content: Gorilla Brake Beefer was an old school brake booster than came in a u-brake version. it appear this booster came with mounting hardware too (which I covet!).QUOTE]
> 
> https://www.abundantadventures.com/quads.html#BEEFERS
> 
> ...


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## richieb (Oct 21, 2004)

I think that's theoretically possible, but you'll have to file the slot in the Evolution mounts to fit over the larger u-brake boss.

I have a u-brake frame in the shop right now, in addition to a few Evo mounts. I'll check it out and report back


rb


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## mainlyfats (Oct 1, 2005)

WTB-rider said:


> The _987_ is a cantilever brake, the _997_ is a BMX u-brake.


Pretty sure it's just a 990. No 7 in the mix at all.


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## stan4bikes (May 24, 2006)

*well*



mainlyfats said:


> Pretty sure it's just a 990. No 7 in the mix at all.


thay are marked 997's but I mis-typed "diacomp" shoulda been "diatech" (but I think it's the same company?) They are marked "Diatech Magic"...they sure look like U-brakes to me...


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## WTB-rider (Jul 25, 2004)

mainlyfats said:


> Pretty sure it's just a 990. No 7 in the mix at all.


As Stan said, marked DiaTech.


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## Howley (Nov 23, 2005)

*Roller Cam SlingShot*



Rumpfy said:


> A roller cam'ed Slingshot would be the coolest thing EVER!


Just for you...









Front and rear Suntour Cams from 1986:


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## KDXdog (Mar 15, 2007)

Scott SE U brake with Gorilla plate.


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