Brake mount broke off....
06-03-17, 03:15 PM
#1
Bar Ends Forever
Thread Starter
Brake mount broke off....
Was tightening my v brake back on after doing some work on it today and this happened. The brake mount just snapped. Is it replaceable? If I took it to a shop could they remove it and install another?
06-03-17, 04:08 PM
#2
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Look at the base (the part that's left). It should have two flats on it. If so, put a (long) wrench on it and unscrew it. I'm not sure where you can get an original replacement, but if you want to go fancy you can replace it with titanium.
I replaced all four of the pivots on my "winter" bike with titanium parts (along with many of the other fasteners). I got them from Toronto Cycles Paul Brakes,, Titanium Dura Ace, CNC Bike Brakes.
The only thing you need to do is measure the threads on your pivot so you can select the right one.
No more rust!
Steve
I replaced all four of the pivots on my "winter" bike with titanium parts (along with many of the other fasteners). I got them from Toronto Cycles Paul Brakes,, Titanium Dura Ace, CNC Bike Brakes.
The only thing you need to do is measure the threads on your pivot so you can select the right one.
No more rust!
Steve
06-03-17, 05:29 PM
#3
Senior Member
That may very well be swaged into the frame fitting, judging from what it looks like, in which case the whole assembly would need to be replaced by a frame builder/other person with brazing/welding skills.
An alternative would be a kit that Problem Solvers used to make to salvage cantilever studs, assuming you have enough threading left, and can find one.
An alternative would be a kit that Problem Solvers used to make to salvage cantilever studs, assuming you have enough threading left, and can find one.
06-03-17, 06:30 PM
#4
Bar Ends Forever
Thread Starter
Look at the base (the part that's left). It should have two flats on it. If so, put a (long) wrench on it and unscrew it. I'm not sure where you can get an original replacement, but if you want to go fancy you can replace it with titanium.
I replaced all four of the pivots on my "winter" bike with titanium parts (along with many of the other fasteners). I got them from Toronto Cycles Paul Brakes,, Titanium Dura Ace, CNC Bike Brakes.
The only thing you need to do is measure the threads on your pivot so you can select the right one.
No more rust!
Steve
I replaced all four of the pivots on my "winter" bike with titanium parts (along with many of the other fasteners). I got them from Toronto Cycles Paul Brakes,, Titanium Dura Ace, CNC Bike Brakes.
The only thing you need to do is measure the threads on your pivot so you can select the right one.
No more rust!
Steve
) so it's probably welded or something.
06-03-17, 06:38 PM
#5
Bar Ends Forever
Thread Starter
That may very well be swaged into the frame fitting, judging from what it looks like, in which case the whole assembly would need to be replaced by a frame builder/other person with brazing/welding skills.
An alternative would be a kit that Problem Solvers used to make to salvage cantilever studs, assuming you have enough threading left, and can find one.
An alternative would be a kit that Problem Solvers used to make to salvage cantilever studs, assuming you have enough threading left, and can find one.
06-03-17, 07:46 PM
#6
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Magnet test, broken stud is steel, frame is aluminum? Clean it off and look for a braze line. It may be threaded in and Loctite-ed or epoxied. Can you see the butt end when you look through the back side? Excess glue / Loctite visible back side? A heat gun will soften epoxy or Loctite. Ask the frame maker how they did it, they may have parts or give you advice.
06-03-17, 07:48 PM
#7
Senior Member
This is simply an FYI, not casting blame, or even suggesting that you were at fault, but keep in mind that the tightening torque for that bolt (which is, surprisingly, agreed on by most manufacturers) a paltry 6-8nm. They rely on threadlocker of some sort to make up the rather low torque for a bolt that size, in order to allow the brake to pivot freely on the post.
06-03-17, 08:34 PM
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Here's a sketchy possible work-around. If the threads go through the piece remaining on the frame, you could reassemble the brake pivot piece with a bolt long enough to go all the way through the frame. Use some LokTite.
Not ideal, but I doubt the brake would fail.
The pivot probably failed because the bolt was too short; if it had gone through the frame it would have prevented the pivot from flexing and eventually cracking. Was the pivot made of aluminum (magnet test)? The ones I removed were steel.
Steve
Not ideal, but I doubt the brake would fail.
The pivot probably failed because the bolt was too short; if it had gone through the frame it would have prevented the pivot from flexing and eventually cracking. Was the pivot made of aluminum (magnet test)? The ones I removed were steel.
Steve
06-04-17, 12:43 AM
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Most cantis and v-brakes have a bushing mounted in the arms. The bushing is clamped firmly to the boss, and the arm pivots around the bushing.
I've only seen a grand total of two brakes that turned directly against the boss.
Unless you manage to tighten the screw hard enough to collapse the bushing, torque won't affect the turning ability of the brake arm.
I've only seen a grand total of two brakes that turned directly against the boss.
Unless you manage to tighten the screw hard enough to collapse the bushing, torque won't affect the turning ability of the brake arm.
06-04-17, 02:30 AM
#10
Pokemon Master
Most cantis and v-brakes have a bushing mounted in the arms. The bushing is clamped firmly to the boss, and the arm pivots around the bushing.
I've only seen a grand total of two brakes that turned directly against the boss.
Unless you manage to tighten the screw hard enough to collapse the bushing, torque won't affect the turning ability of the brake arm.
I've only seen a grand total of two brakes that turned directly against the boss.
Unless you manage to tighten the screw hard enough to collapse the bushing, torque won't affect the turning ability of the brake arm.
