Rear brake - uneven braking around the rim

larkim

On my Triban 3 when I use the rear brake there is unevenness in the braking efficacy (and noise levels) around the full circumference of the rim - unlike the front which is entirely even (and as it should be).

What is the likely cause, and then solution to this? Its only something I've noted relatively recently. I can't see anything physical on the rim causing the extra rub, so I'm suspecting that perhaps it needs truing? I'm not excessively heavy (though my wife would disagree) at 80kg and the wheels aren't super light, but there are plenty of pot holes to hit around here, so I suppose that could be the cause. What's the best approach to diagnosing this?

Thanks!

Matt

keef66

If you don't have a workstand, and we're in beginners, so that's likely, whip the bike upside down. (Do it on the lawn, a bit of old carpet or a dustsheet so you don't scratch the saddle / shifters)

Spin the rear wheel and watch the wheel rim where it passes between the brake blocks, you'll soon see if it's out of true laterally or vertically. Squeeze the brake lever and make sure the brake blocks are landing right in the middle of the brake track. You need to be sure they aren't too high and catching the tyre.

If the wheel needs a minor tweak to true it, all you need is a spoke key and a bit of patience. Have a look on Park Tools website or Sheldon Brown for guidance. YouTube also has many explanatory videos to follow.

If it's properly buckled you're probably best taking it to a bike shop to sort.

larkim

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19652605#p19652605]keef66[/url] wrote:

If you don't have a workstand, and we're in beginners, so that's likely, whip the bike upside down. (Do it on the lawn, a bit of old carpet or a dustsheet so you don't scratch the saddle / shifters)

Spin the rear wheel and watch the wheel rim where it passes between the brake blocks, you'll soon see if it's out of true laterally or vertically. Squeeze the brake lever and make sure the brake blocks are landing right in the middle of the brake track. You need to be sure they aren't too high and catching the tyre.

If the wheel needs a minor tweak to true it, all you need is a spoke key and a bit of patience. Have a look on Park Tools website or Sheldon Brown for guidance. YouTube also has many explanatory videos to follow.

If it's properly buckled you're probably best taking it to a bike shop to sort.

Thanks; workstand in the garden tonight I think!

(I'm a roadie beginner, but dad of a MTB enthusiast so I've built up some competence dealing with his bike, but I tend to learn something, sort it, and wait for the next disaster. Wheels haven't been an issue on his MTB, except when the rear mech went through the spokes - and even I could see that it needed professionally truing!!!)