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Old 09-06-08, 02:53 PM   #1
dankup
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Bicycle V Brake Help

My V brakes work fine except for one. My top left brake (front wheel, left side) keeps rubbing the rim when I pedal. How do I move the brake pad away about 3 - 5 mm from the rim?
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Old 09-06-08, 03:03 PM   #2
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Pictures, make/model would help, but is there a screw somewhere on the side not used for attaching the pads? Almost all v-brakes have a screw (sometimes Allen head) that is used to adjust the spring tension which adjusts the brake body and thus the pads in and out.
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Old 09-06-08, 03:35 PM   #3
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Originally Posted by dankup
Ok look. Both springs are in the middle hole. Only ONE brake pad touches the rim when the wheel is moving, the other brake pad is fine (3 - 5 mm away). I want the brake pad that is touching also to be 3 - 5 mm away. There IS a centering screw. What I did was screw it in all the way, it didn't change anything. Then i unscrewed it ALMOST all the way (so it doesn't fall out), and it also didn't change anything.
Ok, assuming you are good with bike mechanics, and your v-brakes are of recent standards you can either 1) loosen the tension screw for the non touching side and then tighten the one for the touching side, 2) fiddle with the combination of washers in the pad set up to thicken the non-touching side and "thin" the touching side, 3) you can change the holes that the springs go in, 4) you might want to check to see if the wheels dish is correct, 5) dismantle the clean, lube and bend the weaker spring, or 6) any combination of the above.

There might be other options, but I can't think of them.
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Old 09-06-08, 03:51 PM   #4
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Originally Posted by dankup View Post
My V brakes work fine except for one. My top left brake (front wheel, left side) keeps rubbing the rim when I pedal. How do I move the brake pad away about 3 - 5 mm from the rim?
First, check to see that the V-brakes are both pulling in toward the rim when the brake is applied, then moving away from the rim when released. Watch the one that's rubbing, make sure it has good movement back and forth. I say this because I've had this problem on three bikes, the brake was frozen, i.e. was not rotating correctly against the fitting.
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Old 09-06-08, 04:05 PM   #5
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Originally Posted by dankup View Post
My V brakes work fine except for one. My top left brake (front wheel, left side) keeps rubbing the rim when I pedal. How do I move the brake pad away about 3 - 5 mm from the rim?
3-5 mm is a l-o-n-g way from the rim. I adjust for 1-2 mm. There's an adjusting screw for minor adjustments to spring tension.
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Old 09-06-08, 05:33 PM   #6
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+1 to what z415 said.
"...can either 1) loosen the tension screw for the non touching side and then tighten the one for the touching side (likely the easiest to do), 2) fiddle with the combination of washers in the pad set up to thicken the non-touching side and "thin" the touching side (more involved than option 1 but may be necessary if other options don't help), 3) you can change the holes that the springs go in (Also fairly simple but does require simple disassemble/reassembly), 4) you might want to check to see if the wheels dish is correct (an easy way to check this on front wheel without disc brakes is to just flip the wheel, remount and see if the rubbing changes and if it does likely the dish needs to be dealt with but that is more complicated than all other choices), 5) dismantle the clean, lube and bend the weaker spring (easy to do along with or in addition to option 3 above), or 6) any combination of the above."

I'd also add this in connection with option 4 - check.. Make wheel is seated properly in the dropouts. If not it can affect brake rubbing. And a further thought is wheel truing in general, of which dishing is one aspect, affects V-brake performance. Rubbing on just one side as you seem to be experiencing, and if it rubs constantly not intermittently, does point to the dishing as more likely. Intermittent rubbing says lateral wheel truing is needed.

Last edited by wmodavis; 09-06-08 at 05:36 PM.
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