Brake pads rubbing

[Blackwell1988]

I'm not sure why but the pads on my front v-brake continuously rub against the rim, I've replaced the pads, re-installed a new brake cable, screwed the adjuster screws as far in as they can go, cleaned the calipers and re-greased them. I've even installed new v-brake levers but when I press the brake one of the pads does not retract fully and stays up-tight against the wheel while the other pad retracts a little better.

My wheel wobbles a little bit when I turn the bike upside and spin it freely but it isn't buckled, perhaps it needs truing but I'm not entirely sure. Not sure if I've just answered my own question there lol

[nfmisso]

1st true the rim; please note that tires may wobble, even if the rim is true.

Release the adjuster screws most of the way on the V-brake arms. Disconnect the cable. As you remove the brake arms from the fork not which hole the springs are in - usually choice of three, inspect the springs - replace if needed. Grease the posts, and reinstall the arms with the springs in the same hole on both sides - middle usually works best for me, but not always.

Each arm should pop away from the rim smoothly and quickly.

Reinstall the cable, use the screws on the brake arms to balance the system so that both arms move away from the rim evenly.

[cny-man]

The key to solving a mechanical problem is not random parts replacement, but a 3 step process:

1. Isolate the operation of component parts of the system.
2. Eliminate each component until only one choice is left.
3. Apply an appropriate solution to that item.

Nigel's solution focuses on the calipers, which probably is the most likely culprit - and if only one pad is rubbing (your title says brake pad*S*) then it would have to be the caliper. By disconnecting the cable you can feel the smoothness and resistance as you push each caliper arm in and release it. The one that rubs has more friction or less spring tension, each of which Nigel's suggestions address.

[Blackwell1988]

Okay brilliant, thanks for your suggestions and information. If the brake cable was measured incorrectly, a little bit short for example, could this cause cables not to pull properly. Also my front brake cable keeps popping out of the barrel adjuster, I have to keep putting it back in and twisting the barrel adjuster around again so it stays in. It's pretty annoying to be honest.

[Joe_W]

(02-19-2014, 03:16 PM)Blackwell1988 Wrote:  Also my front brake cable keeps popping out of the barrel adjuster, I have to keep putting it back in and twisting the barrel adjuster around again so it stays in. It's pretty annoying to be honest.

I can think of two reasons for that
- the cable is not moving freely in the housing (fraying, kinks, not cleaned up housing ends)
- the cable is waaay too long.

Most likely the first one.

[cny-man]

(02-19-2014, 03:16 PM)Blackwell1988 Wrote:  If the brake cable was measured incorrectly, a little bit short for example, could this cause cables not to pull properly. Also my front brake cable keeps popping out of the barrel adjuster

I had actually meant to mention that specifically, but missed it. BOTH rubbing and popping out of the adjuster could be caused by a too short housing (the cable length is dependent on the housing) .