Bicycle Mechanics - Cantilever Brakes: The Toe-in

I made a huge discovery this weekend. I have a Lemond Poprad, which is a cyclocross bike, that I've turned into road bike. Unforunately, I couldn't get away from the cantilever brakes. I've always hated them. They have no power. They are usually squealing like crazy. I've tried at least 3 different brands in the past 2 years. There have been a couple of hills I was going down where I seriously thought I was going to die because nothing happened when I pulled on the brake levers.

I've always been told to toe in the shoes to get rid of the squealing. I've seen how the mechanics at the bike shop do it, and I just followed their example. The way they do it is to basically tilt the brake pad so that the side that is toward the front of the bike touches the rim first. Sounds reasonable.

Well I was out for a ride this weekend and the brakes were just squealing something horrible. I only have one tool (a wrench) to adjust the rear brakes so I leave it at home most of the time. But since I was going to be going right by the bike shop, I figured I'd stop in and if they weren't busy, I'd have them adjust them.

They weren't busy and I'm talking to one of the mechanics (one I'd never seen before) and telling him about them and how I'd had them toed in pretty good, but the pads had just worn down a bit and they need more toe-in. So he's looking at them and tells me they are toed-in the wrong way!! I'm like... whhhaaa?

Apparently the correct way to toe in a brake pad is to tilt the brake pad so that the side toward the rear of the bike touches the rim first. Totally doesn't make sense. So I'm thinking this guy is smoking something really good, but I let him do it.

I take the bike out and do some hard stops in the parking lot and I'm totally amazed. Not only is the squealing gone, but the brakes actually have some power. Not super awesome power like you get with disc brakes, but definitely more power than I've ever felt with these brakes before.

So now I'm thinking to myself how could I have gone on for the past 2 or so years thinking the wrong thing about the toe-in. Just boggles my mind. Especially considering I've had 3 different shops toe the brake pads in the same way I did. I've read it in a book. This guy told me that this is probably one of the biggest misconceptions about brakes. I believe it.

Is it April 1st again, already?

remember to toe them out....

I toe all of them in.....cantis, V's, calipers.....

Is it April 1st again, already?

THat was a particularly well thought out post that shed a tremendous amount of light on the situation and cantilever brakes in general. You, sir, should be commended for your mastery of the English language and your vast experience and wisdom of cantilever braking. I say "Bravo", old chap.

Generally I toe brakes so the leading edge of the brake touches first, then as you brake harder, the increased lever pressure as well as the motion of the rim pulls the brake pad flat. In the case of some bikes, mostly department store bikes with cheap chrome steel wheels I toe them so the trailing edge touches first as it keeps them from squealing. Sometimes I have to do this with cyclocross bikes to keep the whole fork from chattering.

Generally I toe brakes so the leading edge of the brake touches first, then as you brake harder, the increased lever pressure as well as the motion of the rim pulls the brake pad flat. In the case of some bikes, mostly department store bikes with cheap chrome steel wheels I toe them so the trailing edge touches first as it keeps them from squealing. Sometimes I have to do this with cyclocross bikes to keep the whole fork from chattering.

By leading edge, do you mean the edge toward the front of the bike?

That is it, the "front" of the pad touches first. I think Shimano even pictures it in some of their lit. that you get if you buy a set of their brakes. Some times you have to play around with the toe to stop a squealer, from dead flat to seveal mm of toe in one direction or the other.

Park Tools recommends toe in front of pad to contact first.
http://www.parktool.com/repair_help/howfix_cant.shtml

Front of pad touching first is "Toe-In", other end touching first is "Heel-In"

That is it, the "front" of the pad touches first. I think Shimano even pictures it in some of their lit. that you get if you buy a set of their brakes. Some times you have to play around with the toe to stop a squealer, from dead flat to seveal mm of toe in one direction or the other.


Ok. That's exactly what I've always been told before and what I have practiced. Sometimes I actually have to toe in the front of my pads quite a bit to stop the squealers.

You did mention putting the trailing edge (or a heel-in as AndrewP termed it) for some cyclocross bikes. I guess that fits for me since I have one of those. And my front fork is always squealing and chattering. Sometimes it is so bad I am worried that I'm about to go over the handlebars.... which then makes me not use the front brakes so much and the rear brakes more. And that's bad since I've been told the front brakes supply about 70% of your stopping power.

I think I'm going to stick with this "heel-in" technique for a little while and see how it goes.

Another thing I was thinking in regards to the "heel-in". In wet weather, I would think this would work better since the trailing edge would clean off the rim before the rest of the brake pad makes contact. If you "toe-in" then it's the leading edge and that doesn't clean anything so the brake pad is always coming down on wet, dirty rim... well at least for several revolutions.

I've done it reversed with garbage pads to stop vibration rear. This included putting the pad backwards also, long end front.

Then I believe, I rode to my friends bike store and bought a set of red Koolstops and put THEM on correctly.

>jef.

Forget the "toe" facing the front of the bike. The "toe" is the end of the pad that faces the oncoming rim. On a front brake, that is to the rear of the bike. One purpose for this is that any mud-sand-water-etc., will be plowed off the rim by the front tip (toe) and the pad will then squeeze on clean rim. Took me a while to learn too. Read it on a package of Kool Stop pads.

Tom Balmer

Well I dorked with them a bit more. I added a bit more "heel in" since the guy at the shop didn't really heel them in that much. Plus since I had them toe in for so long, the pads were worn uneven. So there was a ton of pad left in the rear, so I just heeled in a bit more so I could burn that part of the pad down more. Also sanded them up pretty good.

WOW, what a difference. I actually stop without a huge squeal... AND have good stopping power. I never thought I'd get good stopping power with this bike. Also, doing it this way totally got rid of the massive chatter I got in the fork.

Wish I'd discovered this in early May before the MS 150 ride... it was super hilly and I hated those decents all because I didn't think I could stop if I needed too.

What's all this "stopping" talk? :)

So in other words, toe-in, toe-out, heel-in, etc..... all mean the same thing depending on which direction the rim is spinning. Now I get it..... I think...

So in other words, toe-in, toe-out, heel-in, etc..... all mean the same thing depending on which direction the rim is spinning. Now I get it..... I think...

I'm not sure about you, but my rims always spin the same way. lol