Squeaky brakes again

[nirakaro]

Last time, a generous toe-in fixed the squeak, but after not many hundreds of miles, it came back. Looking at the pads, there's a couple of millimetres of wear at the front, and none at all at the back, so the toe-in is completely neutralized.
What to do? Choose pads that don't have a front and a back, so I can turn them round? Try different, anti-squeak, pads (recommendations?)? Anything else?

[Mick F]

I've have squeaky brakes from time to time, and it's due to oil and grease on the rims.
I've never ever ever toed in my brake blocks. Never ever ever. I see no point, as eventually as you have found, the wearing negates the toe-in.

Many years ago, I had a cheapo "racing" bike and the rear brake squeaked. Nothing I did would stop it, so I went to the local LBS and he pointed out the problem.

The rear brake bridge was a welded-on steel plate and it was bending and twisting as the rear brake operated. Only cure was to get rid of the cheapo frame.

[nirakaro]

Hmmm ... I tried degreasing the rim with meths. Made no difference at all.

[Mick F]

When mine have squeaked, I just keep braking down the hills and eventually the squeak goes.

Have they always squeaked?

[rjb]

ive cured squeaking brakes by wiping the rim braking surface with a rag with a squirt of WD40 on it. It sounds counter productive but give it a try and report back.

[Samuel D]

Toe-in is automatically preserved as the pads wear if the brakes are used hard. If all you do is scrub off your final walking pace at red lights or drag the brakes on descents, the calliper arms will never twist enough to maintain the toe-in.

You don’t mention what brakes and pads you use. Some are better than others.

[nirakaro]

Yes that makes sense – I do generally brake pretty gently. Doesn't solve the problem though!
The brakes are Tektro CR710. Pads were Clarks CPS301. I think. I've just changed them for something black and nondescript I found in the box of bits. Still squeaks.

[mig]

my front cantilever pads started to squeal last week. i noticed a tiny bit of play in the aheadset on the way in this morning, nipped it up at lunchtime and the squealing stopped instantly for the homeward ride.

[Steve O'C]

Had the same problem with my V Brakes caused by wear in the bushing. Not helped by any amount of fiddling with the pads or cleaning the rim. Replaced the brakes and silent braking again. I assume the same thing can affect cantis.

[Brucey]

Tektro 710 and Clarks CPS301 may result in a brake with the brake block set a little bit too far backwards (on the front brake). because CPS301 has the mounting offset and so does the brake. It might be worth trying some brake blocks with the mounting in the centre instead.

BTW if the mounting bolts are not quite tight enough that can make the brake more likely to squeal too. NB don't overtightene the bolts; IIRC with this type of brake the post itself can fairly easily fail.

cheers

[francovendee]

Had the same problem with my V Brakes caused by wear in the bushing. Not helped by any amount of fiddling with the pads or cleaning the rim. Replaced the brakes and silent braking again. I assume the same thing can affect cantis.

I ended up doing the same thing. Tried all the cures I'd had suggested to me and watched lots of Youtube showing how to fix it. Some made a difference but none cured it. New set of V brakes and I have silent braking again.

[Mick F]

I'm not very familiar with V brakes, but what I do know, is that the brake arms are long.
Hence flexing ........... as per my earlier post with a cheapo frame and flexy plate steel rear brake bridge.

Maybe, normal length calliper brakes don't suffer from squeaking so long as they're mounted securely.

[pwa]

Hmmm ... I tried degreasing the rim with meths. Made no difference at all.

I tried meths and found it didn't work too well. My theory is that meths dilutes the oil and you still end up with a film left. Hot water with washing up liquid works better for me, it's cheaper, less messy and if it doesn't work you have wasted five minutes and 2p of hot water / Fairy Liquid. I go round the rims a couple of times with lots of water, rubbing with a slightly abrasive sponge intended for non-stick pans. The sort that doesn't scratch. And I clean the brake pad surface the same way.

If oil is the culprit you would expect more squeal from the rear wheel. That is going to be the dirtiest.

[mig]

i've found the key is to rinse off the substance used to clean rims....degreaser, WD40, soaps etc. any left on the rim gets onto the blocks and sets up that slip-grip cycle that causes the noise.

[Patrickpioneer]

I use nail varnish remover (pink stuff from the local shop) but you need to clean the blocks as well, works for me till they all get oily, filthy again.
Patrick