bent rear brake

[Privateer]

i had an unplanned get-off last week which ended in, among other things, a bent rear brake lever/pedal.  what's the best way to bend it back to some semblance of straight?

I mean I have some ideas, but figured someone here was done it more than once and I don't want to screw it up and destroy it and have no lever.

[stopintime]

I've done that with a Leatherman - just to get friends to our destination - didn't look perfect, but worked.

[S21FOLGORE]

This would be one of the best way.



The key point(s)

1)It is far better and easier to do it with the brake pedal removed from the bike.
2)It is usually better to use mallet and vise, than using pliers and trying to bend it back.
(What I mean by that, is, that if you hold the pedal by two points (by two pairs of the pliers, for example) that are close to each other, you have way more chance of snapping it off.)
3)Don't try to make it perfect. All you want is to get it close to where it was (so that it will function again.)
4)Oh, and applying heat helps, a lot.

These video also helps, I think, to explain what I'm trying to say in 2).

Watch how he bends aluminum flat bar (1/4" thick) WITHOUT applying heat. The distance of the two points that you apply the force plays big roll.



Example of making 90 degree bend with heat, vise and hammer. (1/8" thick aluminum flat bar.)

[ducpainter]

...and above all, remember your lever is cast aluminum, and doesn't bend like any of the materials in those videos. It breaks much easier.

[S21FOLGORE]

remember your lever is cast aluminum

True.
There's no guarantee that you won't break the brake pedal even if you do it slowly, with heat.

That said, I have done it, many others have done also. (And, yes, I have broken off the lever while attempting to fix it).
It greatly depends on how it is bent, and how you try to bend it back.
(If you use vise + mallet, use the plastic faced one, or use 2x4 between hammer face and the pedal.)

And some people do it in a funny way.


(The lever is also cast aluminum, will break off pretty easily.)

[Howie]

Nice neat workplace in that last video 

[NAKID]

I echo the mallet and vise versus pliers method. I've fixed a bent shifter (also cast aluminum) back to near perfect by slow, even smacks with a urethane mallet. With your level of bend, probably 20-25 well placed smacks will get it back to usable condition.

[Privateer]

thanks.  jeez getting the pedal off was way harder than it should've been.

[Speeddog]

If it's bent the lever a lot, it's usually bent the bolt too.

Best to hold the pivot end in a vise with jaw pads, then straighten.
Check the alignment of the adjuster screw and the switch, make sure that's good.
Test fit without the spring, make sure it feels OK.

Sometimes the switch plunger nose gets bent over and stuck, you can straighten that too.

[DuciD03]

have bent a couple of shift / break levers back by

putting in a heavy bolted down vice; using aluminum pads in vice teeth to hold bent lever; removed rubber; heated with plumbers propane torch, then slowly tapped with hammer or bent with adjustable wrench until straight;

watch to not over or under heat too much heat and you can turn your nice aluminum lever into a puddle of liquid aluminum; too little and it may just snap ... idea is to make it malleable ;

don't know if a casting would be heat treated / hardened (someone more knowledgeable abut cast aluminum please advise) ...So there's a bit to think and worry about ...

[Privateer]

well i got it mostly fixed.  honestly I think I straightened it too much because it's really close to the engine case now. 
whatever.  rarely use it and when I do all it does is lock up anyway.  maybe if I can't hit it as easily it won't lock so readily.

for future reference I used a heat gun and a vice.  took a while to get enough heat into it, and I couldn't really get the toe post horizontal, it points a little up.  i tried different angles in the vice and other combinations of turning and hammering, but couldn't get it.


thanks everyone.

if this rain we got clears out I'll be test driving tomorrow.

[DuciD03]

1.... I think I straightened it too much because it's really close to the engine case now. 
whatever.  rarely use it and when I do all it does is lock up anyway. .

2... I used a heat gun and a vice.  took a while to get enough heat into it, and I couldn't really get the toe post horizontal, it points a little up.  i tried different angles in the vice and other combinations of turning and hammering, but couldn't get it.

1- Might be lever might be adjusted too high; try adjusting lever lower; check too see the reservoir isn't overfilled fluid; etc; breaking is 70% front 30 % back on a bike; no locking up either ... as you know...

2 not enough heat in a heat gun; needs to get towards red hot; so you need propane; haven't tried, but acetylene is supposedly too hot; there's a fine line there before melt-age.

From what your saying; Id try arm of lever in vice, with adjustable wrench, in various spots... hammering not as nice = breakage