rlong

My rear canti brake is located under the chain stay, sort of like some BMX brakes. Both front and rear have been very difficult to keep in adjustment and finally broke. The front is easy to replace, but the rear brake is weird to me. as it is huge compaired to most cantilevers. Any suggestions, short of brazeing on a new boss where it belongs (not out of the question)?

XzEn54321

Just get a new set, center pulls anr really cheap.

Raiyn

It sounds like a early 90's / late 80's Specialized with those damned U brakes. You're pretty well hosed as far as replacing one of those with anything better.

cyccommute 

Yep! It sounds like a U-brake. U-brakes weren't just on Specialized but on all kinds of mountain bikes throughout the early 90's. The bad news is that you can't replace them with any thing else since the bosses are in the wrong spot for canti's or V-brakes. The good news is that they are still used, somewhat by the BMX crowd. Check here https://www.americancycle.com/cart.cg...evers_hardware or at Airbomb (click on any of the categories). Good luck.

Stuart Black

mtbikerinpa

Yep, BMX guys like the feet clearance. If you got a good set then they can be decent.
That said, I converted my cromoly Sedona frame to Disc from standard canti. On cromo it was just a matter of getting a plate of steel and shaping it and drilling it. I had a friend mig-weld it on and its been soo much better. If its aluminum, well... thats a little trickier but still doable.

rlong

Yes it was about 1985 and it's a KHS bike. Really more of a tour bike if you ask me. But back then, just about anything could be called a mountain bike. The brake arms are very long and I'm certain my son (a wrench) said they were BMX brakes.
thanks

rlong

Thanks everyone. The idea of converting to disk is tempting, but naaa.

rlong

I looked at the BMX site and it appears to resemble a U-brake. I did find (in very small print), BF Suntour stamped on the bottom of both arms. I never noticed it before.

mtbikerinpa

If its SunTour then there is some collector value if anything.

rlong

OK, here it is; I found them on-line. They are Suntour XC Power Brakes CB6000, rollercam design, licensed from WTB Cunningham "the popular XC powercam brakes." They sucked when they were new and they suck even more with broken adjustment springs. It says they cannot be replaced with standard canti's. The pivot is in the middle, shoe at the bottom and levers at the top with a cam plate separating them and attached to the brake cable.

I think I may have to braze a set of canti posts on to replace these things.

seely

Tangent:

I will never understand why Cunningham is exalted as the god of MTB when he gave us chainstay mounted crappy U-brakes, and elevated stays... two of the stupidest designs in the history of mountain biking.

rlong

Found nearly new Shimano Deore XT for front, and some weird thing for the back; the arms cross over and pull from center very strong. Problem solved.