Grinding noise when braking

bikeit65

I noticed a few weeks back a grinding noise from both wheels but a lot louder noise from the back wheel whenever i brake hard, i have checked the rims for wear but they seem fine and the brake blocks didnt have any grit or small bits of metal embedded in them,
any ideas what it could be or what else to check.

adifiddler

It sounds like you need to toe the blocks in by tilting the front of the blocks in so they touch the wheel slightly before the back of the block touches.

AndyGates

There's muck somewhere. Clean everything again - that the rear wheel is worse is a clue, because the road muck and grit is always worse on rear wheels. Get the wheels out and scrub them, scrub the brake blocks with a toothbrush, and once clean and dry, inspect for embedded bits of hard stuff - pick out with a knife.

overmars

What's been said seems pretty spot on. If the sounds coming from the brakes when applied then that's a big clue to where the problem is.

I hate it when you hear a little noise on the bike and you don't know where the heck its coming from!

passout

Dirty pads - clean 'em and see if the noise does. Check the rims too.

bikeit65

Thanks all, washed all the parts that could be causing the noise, noise still there but nowhere near as loud.

OnTow

Mavic rim cleaning block is good, if somewhat expensive.

Either that, or an old rag held tightly against the rim , with something ilke Muc-Off degreaser, normally does the job.

For the pads, you could take them off and rub them over a file, to lightly skin them / rough them up again / de-glaze them (if you've been rattling down the descents).

I guess there's no Muck around the tops of the chainstay where it joins the BB rubbing against the wheel?... Hmm... Maybe I've been doing too much off-roading

bikeit65

Cheers OnTow. Where can i get some Mavic rim cleaning block.?