October 27, 2011

Fixing v-brakes

Last night I fixed the brakes on my city bike. One of the arms of the v-brakes wasn't moving. This happened both on the front brake and on the rear brake too. I asked a guy from the bike shop how to fix the problem and he said that probably it got rusted or some dirt caused the brakes to brake.

I went home and unscrewed the screw but the brake arm didn't come loose. I gave up after a few tries and abandoned the project. After I turned on my laptop I searched on the web for a tutorial to fix v-brakes and I found this video:

Although my brakes are a bit different I got the tools and unscrewed the screw again. This time I got a screwdriver and tried to force the brake arm. I didn't succeed at first but then I started to twist the arm and it started to get loose. I found out that a lot of rust was causing the brake to malfunction.
the rust
the tools
I cleaned the brake with a fine sand paper and then like the guy does it in the video I greased it up an resembled it. It was working so well that the other side, which was working before, got stiff. So I had to clean the other side too.  

After fixing the front brakes I did the same thing to the rear brakes to. The rear brakes came off a lot easier.
The whole operation took me about 40 minutes but next time I will be a lot faster because I know what to do :D

The rear brake got stiff a bit but maybe it will recover in a few days, if it doesn't I will lube the cable. I didn't line up the brake pads with the rims eater because I'm expecting the springs to get loose a bit after they were stiff for a while.

3 comments:

  1. Nice tutorial. Three comments:

    1) There might be dirt or rust in the spring itself. I read elsewhere that some people have success with cleaning the spring, ie soaking it in WD40. I sprayed a bit of WD40 on mine and ran a tiny screwdriver up through the spring coils. I am not sure if is was necessary though, or even if it made any difference since I didnt compare to the alternative. But the end result was good.

    2) It seems like a bad design if tightening the bolt too much, means that it is pressing on the arm. Imo the bolt (and the washers) should only press against the "shaft" coming from the bike frame, and it should be designed such that even when tightened to the max, there should be room for the arm to move.

    3) I ran into one problem on my bike. The slot on the adjustment screws were very rusty, and it was very hard to turn them. I guess it would be nice to buy replacement screws. I am sure no bike shops sell it, at least not here in Denmark, since they prefer to sell you a pair of complete brakes instead. But maybe I could find such screws in a hardware shop.

    Thanks again :)

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