Squealing brakes

Kool Stop pads.... they even silence Mafac Racers. Some claim the the red pads are quieter than black.

I have 600 ex brakes on my Trek, with Shimano pads & Arraya narrow rims.  Pretty sure mine are the short reach model.

I also have Campy and DuraAce side pulls with narrow alloy rims. All are quiet.


I still think its the pads.  Maybe you could swap out different brand pads from some of your other bikes and see if that solves the problem.


As an aside....
Back in my racing days, I always knew (from my position far behind the pack) that there was a hard corner coming up from the squeal of the Mafac Racers at the front.

M.E.W.S. (Mafac Early Warning System)

My brakes squeal when wet, although that is the cantilevers on my Witcomb. My toe-in method: I just fold over a piece of card, the fold goes to the back and I wedge the blocks up to the rim, tighten all up then pull the card out. Repeat until satisfied, usually about 2 hours is enough......

Something there is causing serious resonation!

It could be pad/rim material, but most brake squeal is caused by the alignment of the pads against the rims.

Over time, the grip of the blocks against the rims causes the caliper arms to try to rotate, particularly if the brakes have plenty of hard use. This brings the rear edge of the blocks closer together and as the rim passes between the blocks the first part of the block to make contact with the rim has a sharp edge that causes resonation - it's almost trying to dig into the rim - and it's this resonating action that causes the squeal.

Assuming you didn't have this trouble with the previous blocks, try swapping the blocks - left block to the right and vice versa.

If this fails, try blocks made from a different material.

Another cure is to place a small piece of, say, a business card between the caliper and the front edge of the block, so that as the rim passes between the blocks, the last portion (the trailing edge) of the block is closer to the rim than the leading edge.

I cured a squeal on a Raleigh Twenty last week by gently twisting the calipers, which are pressed steel.

Alloy calipers won't have the same give in the material, so I wouldn't recommend trying to twist them. Instead - and if you don't want to risk twisting steel calipers - try swapping the front and rear calipers. They normally face opposite ways on the bike, so any twist occurs the opposite way front and rear, and I know it's a pain to swap them, but it may silence a squeal.

So, in order of difficulty, easiest first:-

Swap the blocks to opposite sides;

Try blocks made from different material;

Piece of card between front edge of caliper arm and body of block;

Gently twist front edge of caliper arm in towards the rim;

Swap front caliper to rear and vice versa.


Hope this helps.

The squealing is usually caused by the blocks not being parallel to each other or, ideally, ever so slightly toed in to the front and a loose pivot bolt(s). It always amazes me just how wonky brake arms are - all my side pull and centre pull brakes invariably need a bit of straightening before using. Considering they are usually cast items how come the manufacturers get it so wrong so often?

MUST try harder if any of them are reading this (unlikely?)

Glad yours are sorted!

Cheers

Steve

Ade,

They should look like these:


600ex_brakes by ShouldbeCusquenobutF**krwontletmeintomyproperaccou, on Flickr

I have some spare wiry bits that I bought by mistake for 1st Gen Dura Ace ones, which are different.  We could reach an arrangement over those. The original shoes were alloy, but steel ones look virtually the same and are more easily available.  If you are going to do 46MPH downhill frequently you might like to go for modern pads.