Bent Canti Brake post

[Spibblo]

I suspect I have a bent canti post/stud on the front forks. I cannot get the brake arms on my cantis equal each side. When the brake arms are held against the rim, both pads in full contact, I can see one arm is nearer to the rim than the other The brakes are modern Tektro cr 720's fitted to my old Fisher. Have spent about an hour changing this and that but the result is always the same, the brake arms stand at different angles when applied, and this causes one brake arm to remain stationary when the lever is operated.
This is not due to spring tension, wheel alighnment or the distance the pad is from the brake arm (as this is a fixed distance on these brake pads, like V's in many ways) I've checked all this already

so a bent brake boss, what am I to do? I have been eyeing up the hammer but that feels wrong, like I could make it worse...

 

[stuey]

<If your sure its not the brake - have you tried another?>

I'd be tempted to thread a long bolt into the brake stud and slide a narrow steel tube over it and carefully try to cold set it /lever it back. Good luck

 

[Radar]

As Stuey says; make sure long bolt goes all the way in - you want to keep the boss thread integrity. Slow and steady should be your mantra.Tricky bit is guessing the correct position (maybe put another bolt and lever on the other side to make it easier to find the same position)

Alternatively - a frame builder should be able to fix it (one way or anothewray

 

[02gf74]

I suspect I have a bent canti post/stud on the front forks. I cannot get the brake arms on my cantis equal each side. When the brake arms are held against the rim, both pads in full contact, I can see one arm is nearer to the rim than the other

re: one arm is nearer - what do you mean by that - a photo would help.

flip the wheel the other way round to rule out a non symetrical rim.

if the boss was out, you would see the gap between the pad and rim change - adjust pad so that is touches the rim at all points then when brake is not applied, use a vernier or bocks of wood to see if the gap has changed between fornt and rim.

..... it does sound like you have a good reason to fitting disc brakes.

 

[unkleGsif]

I love the term "Cold Setting".....
Engineer speak for "bend it back"

G

 

[bren]

Copper faced hammer a decent straight edge and a steel rule is all I use. A keen eye and feel for twatting steel is also of benefit Done a few now. It's surprising how little effort is needed to bend them (cough! I mean cold set)

 

[stuey]

'Once in your life' everybody should see a talented frame builder 'cold set' the rear drop outs on their pride and joy - "your using a pry bar how big!"

 

[Spibblo]

'Once in your life' everybody should see a talented frame builder 'cold set' the rear drop outs on their pride and joy - "your using a pry bar how big!"

seen it, it's not pretty

 

[Spibblo]

thanks for all the input. Will have another fiddle tonight see what can be done.

would adding a spacer behind one of the pads help?

staving off the 'cold set' hammer bash for now

 

[drcarlos]

Had a bent boss on the Saracen forks, cold set it back in place with a large set of grips.

Carl.