Has anybody here heard of brake bosses that break due to odd stresses?
Early disc frames had disc brake mounts that ripped out when riders were backhopping and doing trials techniques that stopped the wheel from moving BACKWARDS instead of the 90% of forwards movement that almost every other rider was stressing the frame with.
I was curious if this sort of concern exists for V-brake bosses and mounts. Given Magura HS-33s and the like, I would guess no, but this NG is full of experience so I'd like some input.
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Quoted message said:
Has anybody here heard of brake bosses that break due to odd stresses?
The brake bosses that I've seen broken off were mostly due to a severe blow to the arm, mostly the brake arm going into the spokes in a crash (or otherwise) or being hit by another bike. I have seen one or two (?) that simply broke off while tightening the bolt. I attribute this to some type of fatigue, either from repeated assembly/disassembly or just repeated abuse. The fatigue cases broke the post off, the others sometimes broke the post and sometimes the weld. Overall, those failures are pretty rare, more rare than broken rear dropouts either by crash, fatigue or derailleur malfunction. That's my experience in about 10 years of working in a shop, no hard statistics.
Has anybody here heard of brake bosses that break due to odd stresses?
Only due to a defective brazed joint or non-braking- related stresses (e.g. crash, roof rack incident, etc.)
I have personally broken more or less every breakable part of a bicycle at one time or another, but not a canti boss. Nor did I ever see one when I was a shop mechanic that had failed due to any kind of braking load.
I witnessed one detach that had been held on with mostly paint and wishful thinking.
I have personally broken more or less every breakable part of a bicycle at one time or another, but not a canti boss. Nor did I ever see one when I was a shop mechanic that had failed due to any kind of braking load.
Thanks for your comments. I was concerned that with numerous stoppies and backhopping from doing trials, my brake bosses (part of a magnesium casting on the fork, and the alu frame) would fatigue over time and would snap off. I've broken my fork arch already, but that was Manitou's design fault and is now fixed.
