I replaced my brake pads (old ones were worn to the metal plate), and now the front wheel is squealing VERY loudly - people stop and turn wherever I go.

I read up online, and it seems this has to do with toe-in. From visual inspection it seemed that the front of the pads was touching the rims before the back, so I thought something else was going on. I reset the pads and cleaned the rims with alcohol, and managed to get the squeal to be a tad bit less loud, but it's still very much there. So I pulled the pads, and I saw that I was wrong and toe-in is all out of whack (for lack of a better term), with the back of the pads having a lot more wear than the front:

https://img85.imageshack.us/img85/5982/brakes1.jpg
https://img838.imageshack.us/img838/2021/brakes2.jpg
https://img52.imageshack.us/img52/8426/brakes3.jpg

So I want to set the toe-in properly, but I don't know how. I don't see any adjustment on the brake arms that would allow me to somehow rotate the angle of the pad, and I know I'm not supposed to bend them with force or they could break.

What to do?

Thanks.

There's no precise formula for toe-in, but it helps to understand what happens when the brake shoes touch a moving rim.

As the brakes engage the moving rim pushes the brake shoe forward imparting a twisting force to the brake arm and bringing the toe out slightly. The rear corner now touches alone and squeals in a way similar that new chalk sounds on a blackboard. The squeal usually goes away with increased brake pressure which forces the show down flat.

With wear the rear corner breaks down and the noise goes away, but to get the most even wear from your shoes you want to toe them in slightly to offset this twisting so they lay flat on a moving vs a stationary rim. The correct amount of toe in depends on the friction property of the shoe and the rigidity of the brake arm. I usually use a piece of cardboard (about 1/32") trapped under the rear of the shoe to establish toe-in when I mount new shoes.

BTW- a better way to reduce or eliminate squeal is to use a file to break down the rear corner of the shoe slightly before installing. Also note that toe-in isn't critical since shoes will naturally wear more in the rear until they establish they're own toe-in anyway. But excess toe-in should be avoided because it uses up avalaible brake travel and makes the brakes feel spongy.

Toe In - the leading edge of the pad should touch the rim first, before the trailing edge (front of the pad - facing the front of the bike, should touch before the rear).



Another thing that will affect squeal is the looseness of the brake arm pivot points.

If the rear touches first, that causes the pad to "chatters" against the rim as the edge lossens/holds/loosens/holds against the rim.

And sometimes....a certain combo of pad and rim, just squeals to high heaven until broken in.

Leave the brakes just like they are. It will warn people to get the hell out of your way!

Don in Austin

Loosten the bolts on both brake pads and slide a small piece of old inner tube or the like between the back half of the brake pads and the rim. Now squeeze the brake pads firmly against the rim and tighten the bolts, and you will have the correct toe-in. I'll try to post a video for you in a moment.

Here you go..... https://www.youtube.com/watch?v=nb1AIjXmnbw