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I recently purchased an old bike and got the brakes replaced. My front brakes are working as expected and my rear brakes are not. I am squeezing my brake lever which has a lot of resistance, but isn't really tightening my brakes. My brakes are moving a little bit but the line flexes a lot.

My brakes are properly installed and the line on that end is attached properly. Any ideas what the issue could be?

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On a flat surface, braking power is distributed 70% front and 30% to the rear. The front distribution only decreases when going uphill, so I wouldn't be that concerned. – OMG Ponies Oct 30 '11 at 20:00
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I would still like my back brakes to work though. I've been flipped over my handlebars once too much =) – Kyle Hotchkiss Oct 30 '11 at 20:12
Did you replace the brakes yourself or did someone else do it? – krs1 Oct 30 '11 at 20:18
You're flipping because you're weighting too far forward -- nothing to do with the rear brake. – OMG Ponies Oct 30 '11 at 20:22
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@OMGPonies - Irrelevant. Kyle - What kind of brakes? What kind of bike? Cable I assume? How old is the bike, approximately? – jm2 Oct 30 '11 at 22:33
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2 Answers

up vote 3 down vote

From your description the brake cable (or the rear caliper) may be rusted up. (Although, if you "got the brakes replaced" whoever did that should have checked brake operation and lubed the cable and caliper if necessary.)

Observe the rear caliper as you squeeze the handle -- gentle motion on the handle should result in smooth closing of the caliper, and you shouldn't feel any significant resistance in the brake lever until the caliper is closed against the rim.

Do note that there's a lot of stretch in the rear brake cable (because it's so much longer than the front), so once the caliper is closed against the rim the cable will continue to stretch as you squeeze.

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up vote 2 down vote

If you feel resistence but the caliper is not moving, I almost bet the problem is inside the cable housing, most probably dirty/rusty, bent or frayed cable. I would recommend the following diagnostic procedure:

Detach the front end of the brake cable from the lever (most levers allow you to do so). Grab the cable "head" with one hand, and the housing with the other, and try to move the cable inside and outside the housing. You should feel the cable running almost free inside the housing, and the cable exiting from the other end.

It is important to distinguish between a single long cable housing from the lever to the brake, and many short stretches of housing, so as to test each stretch independently. If that is the case, you can free the housing from the frame braze-ons (allowed on most frames nowadays), and verify that the cable runs free inside all of them. If not, you found your problem.

Don't forget to check for the curved metal part if it happens to be a V-Brake.

Hope it helps.

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+1, also check if the calipers themselves are binding or not. It could be that they're tightened too much and can't pivot freely. If the brake is properly adjusted and rust-free you should be able to squeeze the lever and have it snap back very quickly when released. – Angelo Oct 31 '11 at 15:35
@Angelo : +1 for the snap back! – heltonbiker Oct 31 '11 at 17:23

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