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Old 2019-11-25, 02:52 AM   #1
Canoeheadted
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Repairing bent brake lever

So my brake lever on my KH29 has taken so many hits that it is bent further down than it should be at the very tip where the Strarfighter attaches.

Can I heat this aluminum lever up with a blowtorch and then bend it back up to it's original shape?
I'm worried that it may break when I bend it back and then I have to replace the whole brake.

Other option is to use it as is because it is still working.

Thanks if you can help.
Ted
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Old 2019-11-25, 04:21 AM   #2
JimT
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My only experience with heating aluminum brake levers is that there's a sudden transition from not hot enough to too hot where it just melts and lets go. IE, aluminum melts at or around 1200f, and doesn't show heat up until it melts.

I would say you may be able cold bend it back. I would not heat it because it doesn't act like steel. I and others have reported online, heating al with a torch when all of a sudden it broke in half (melts).
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Old 2019-11-25, 05:04 AM   #3
Canoeheadted
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Thanks Jim.

I might just wait till I have a spare ready to go then go for the cold bend.
Appreciate the advice.
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Old 2019-11-25, 05:26 AM   #4
lobbybopster
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The Handle

Let us know the brake, one of us close by may have one to spare.
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Old 2019-11-25, 08:26 AM   #5
OneTrackMind
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Aluminium work hardens and fatigues very quickly. Bending it back is very likely to snap it.

There is a level of heat that will allow it to bend but it cannot be judged by colour because it is below red. It is the temperature where oil smokes.

I have done it before on one millimetre sheet aluminium where a ninety degree fold was done in the wrong direction. We just used light machine oil IIRC. The correction was 180 degrees. This would definitely snap without heat and it worked fine using the oil smoke indication.

With sheet you put oil on one side and heat the other. Harder with a thick piece as you need to get the heat right through it or the inside will crack. Maybe heat it slowly or even dip the end into a hot oil bath to soak the heat in first. Be very careful with the hot oil though as it could easily catch fire or burn you severely.

The other alternative indication would be to use a non contact infrared thermometer to judge the temperature.
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Old 2019-11-25, 08:50 AM   #6
kunstrasen
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The stock brake is Shimano. Their brake levers start form about 20,- Euro. A SLX lever with tool free lever adjustment for example is 28,-Euro.

If you really have an issue with your current lever, I believe this is the easiest fix. You have to bleed the brake after changing lever. Make sure to not tighten the lever too tight, so that it can rotate away in case of a UPD.
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Old 2019-11-26, 10:07 PM   #7
Canoeheadted
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Thanks for all the help everyone.
I have my wife looking online to source the lever, but so far no luck.

Does anyone have a Shimano BR-M447 brake (or just the lever if I can change that) kicking around gathering dust?
Maybe we can make a deal.

Thanks in advance.
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