Why Rear U-Brakes ?

[velomaniac]

This is a follow on to an earlier question regarding whats the oldest mtb you own.

From the replies showing pictures a couple of the older machines have rear U-Brakes as opposed to cantilever brakes that would match the front.
Is there reason for this or were there just an excess of rear U-Brakes back at the factories at the time that needed used up !

For that matter when did cantilevers start to take over from U's or did both systems operate alongside or even as above in complement to each other ?

Always seeking more facts,

Velomaniac

 

[The Ken]

I always thought u brakes were more powerful but that canti's were used as a weight saving exercise... over time weight and most definitely mud clearance took precedent over power.

 

[cherrybomb]

U brakes cerainly stop you just as well as cantis don't.

Unfortunately mud clearance and weight savings put an end to u brakes. :cry:

 

[shovelon]

My bro has a scwhin with a U brake mounted on the chainstay. Looks like it built like a monster truck.

 

[tintin40]

Also early U like the XT are a sod to set up, ask jez. he has had a few posts seeking help.
I used Dia-comp and they were pretty easy to set up and can be light.RBG has a 'bling'one in ano red on his Trimble.

 

[justbackdated]

Suntour roller cams under the BB were the hot set-up when i built my frame in about '87. That was until it was found they just clogged with mud/leaves/rabbits etc and the springs did'nt "spring" :?

 

[pete_mcc]

Key issue with old cantis was that they stuck out a mile, so if you tried to drop off a steep step then you would always catch your leg or calf on the buggers and cut yourself.
U brakes and rollers avoided this but were also a fair bit more powerful when set up correctly and used with 4 finger brake levers, infact the main reason they were put on the chainstays was that they were thicker than the seatstays and therefore didn't flex as much under braking - great idea in sunny california, not so good in muddy england.....

 

[24pouces]

there's another reason : on small frame, the feets could touch the cantilever brakes when you were pedaling. In 1990-1991, shimano designed low profile cantilevers. So, the problem disapeared.
The 1990 marin bikes used U brake only on small frames.
On other hand : brakes levers used 4 fingers for U brake before the 90ies. When the levers started to use only 2 fingers, the U brake disapear : you needed more strong for braking on the lever. (but U brake was very poewerfull. I think, it's why they stopped to mount it on the fork)