Bicycle Mechanics - Front Brake (Direct Pull 'V') Problem

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Fio
09-23-04, 02:36 AM
Hello everyone

I'm new to this forum and straight away, I have a question. For the last few months, my front brakes have been giving me grief. They are Direct Pull 'V' brakes (Brake Levers Shimano). The bike's only 1 1/2 years old, but is stored outside.

Anyways, it started with the right hand side not springing back after I engaged the front brakes. We lubricated and adjusted the spring and although that made it slightly better I than had a mechanic have a look at it who said they were badly adjusted and he fixed that. Well, so far so good. I thought! After 20 minutes of cycling my brakes started catching on the wheel.

What happens now is that I have to pull the brakes to the left before I start cycling, while I ride along they keep shifting and catch the wheel again so that I keep having to pull them over again! :eek:

Anyone got any ideas as to how to fix this?

Fio

khuon
09-23-04, 02:42 AM
It sounds like one or more things are going wrong.


Spring forces are uneven. You can adjust this by playing with the tension screws or bending the spring. The Park Tool webpage on adjusting brakes (http://www.parktool.com/repair_help/howfix_linearbrakes.shtml) should prove helpful.
Your brake cables are gunked up and fouling. You may be able to remove the cable and clean it up and then spray some lube down the housing or if they've been extremely weathered, just replace them altogether.
Rev.Chuck
09-23-04, 07:52 AM
Sometimes it can just be a cheap brake. Some of the non brand name linear pulls don't like to stay adjusted. They bind a little and the adjusting screw head is not flat so the adjustment is inconsistent. They can also get corroded inside, they pivot on their own bushing not on the brake post and unless you can take the brake all the way apart you can't get this area smooth. You can get a new set for as little as $12 with pads

Balance
09-23-04, 09:26 AM
yeah v brakes don't pivot on the brake boss like cantis. They pivot on a bushing inside the arm itself. The bushing is connected to the spring. If you can take the bushing out from the back of the arm, then you can clean it and regrease it. This will usually help, but if it's very corroded, they won't function the same. I've had a bushing seize inside a brake arm before, and the spring part came right off (it was only pressure fitted). This was with an avid sd, but one that was 8 years old. too much salt... What this tells you is to be careful with v brakes in the winter, regrease regularly.