The Carre frame set I recently acquired came to me with Mafac Criterium brakes. I like Mafac center pulls quite a bit but I've never used Mafac cantilevers before - I read that they're pretty good stoppers. My question: Is it possible to toe in the pads on these brakes?

My understanding is that you need to physically bend them to toe them in... or you could grind the pad down at an angle.

I wouldn't try, and odds are that it's not necessary anyway.

The whole toe-in thing is overblown anyway. In normal use the forward motion of the rim torques the brake arm rotating the shoe slightly causing the heel to dig in, and the toe to lift off. This causes higher wear at the rear, and pretty soon the shoe will wear to a toe-in pattern, such that it's flat, when turned by the moving rim.

So, you don't have to toe in shoes, since initial break in wear will do it for you soon enough.

That said, people toe in shoes because when the heel of a new shoes digs in, you get a new chalk on blackboard effect and the accompanying squeal. Toe-in became popular as a way for mechanics to satisfy complaining customers, who wouldn't accept the explanation that it would resolve by itself.

So my advice is to be patient, and appreciate the automatic horn while it lasts.

However, if the posts don't square up nicely, and the shoes are way off parallel, you might solve it by shaping the shoe to match the rim.

You can, but it isn't necessary. So +1 to above. The only way is to bend them slightly, and if you do this it will last about one ride before the pads are meeting the rim flush again.

Any old stock MAFAC pads still around are unlikely to work properly in 2017. Get yourself some black Koolstop replacement pads and you will be fine. Sand the rim lightly if they squeal, but they probably won't.

If it has the original pads and they are squealing, they are squealing because they are old and dry.

FB that horn has real advantages. In my Boston days decades ago I loved having Mafacs that would howl reliably on hard stops. When a driver cut me off or pulled any other patented Boston move, I would slam on the front brake, then point to the offending car. Every set of pedestrian eyes for two blocks around would swivel toward me, then follow my arm to the offending car and driver. Driver would hear my squeal and look up. Guess what? Everyone he sees is looking at him. Driver slinks off like a scolded cat.

I loved those brakes. Sadly, with the new pads, they don't work nearly as well (as a public PA system; a lot better as stoppers).

Ben

BTW - an alternate method to solve the squeal issue with new shoes is to use a file to break the back corner slightly. Then going back to my new chalk on blackboard analogy, you'll have solved it the same way that allows old chalk not to screech.

I'd skip the black ones and get the salmon. Doc (@rccardr) had the same issue recently, old skanky pads on some vintage RAIDs, and they hardly stopped. New salmons gave him good braking, but they squeeled. Sanding them down so there was a slight toe-in broke them in immediately. If it's bugging you, sand 'em down.

I've bent the arms on centrepulls to toe in / alleviate brake squeaking and broken one in the process.
It's time consuming as it requires disassembly so I don't damage the nylon washers.
Nice once it's set up though.
Some new shoes have an eccentric washer which allows toe in.

I just realized the photo I posted is one I took right after the frame arrived, and the old pads were still in place. I replaced them with a set of Salmon "four dot" Koolstop pads. After adjusting the brakes, I noticed the rear pads weren't quite parallel to the rim, which is why I was curious if there was a way to toe in.


Yes, I've also done that with center pulls. I'd never heard of it with cantilevers though. The pads on these use a post which doesn't allow for the eccentric washer to be of use in this situation.

It's been a long time since I've worked on them or owned them, but IIRC MAFAC cantis aren't super sensitive to toe in. Good well bedded pads, clean scuffed rims and good set up are more important. I'd suggest you just let them bed in a bit unless you are having problems. Also, you might be able to swap the front for the back set - in case someone already tweaked some toe in into the arms.

BITD built in toe in adjustment was pretty much non existent. As cave man as it sounds now, you had to bend it in. Doing it all the time gives you a feel for it, but it is possible to break things. I didn't worry about it much when I had a set of these on my touring bike, but they were relatively cheap at the time. I'd be more careful now.

Adjustable eye bolt for bicycle cantilever brakes



...or you could just file the heels on what you have.

Velo Orange used to sell adjustable toe-in post pads, perfect for old centerpulls. Socket head at the end of the post for an allen wrench, beveled washers built in to the pad. Unfortunately they don't sell them anymore. I was told people only bought them when they were on sale.

Yup, that's what I plan to do. It's really no big deal to do so, I just wanted to make sure I wasn't overlooking something simple and obvious. Thanks for the suggestions, everyone.

Alert- The Criteriums are a complete different animal vs. Racers. DO not twist or attempt to toe-in the Criterium. Doing such will distort the pivot portion / drillings of the stamped plate type arms. Even if you've done it, you'll never get them back to the original factory shape for the next time or adjustment.

FBinNY has the right idea.

But if one wishes to get a quick pad to rim seating, use a flat block w/low grit sand paper and work the pad to desired fit.

Another example -For old time cars with drum brakes and fitting new brake shoes, we call it 'arcing'. With the drum nearby, we take the brake shoe -squared up, laid on its side of the disc sander plate, the shoe pad material is worked against the rotating sander. Very little of the material is shaved with the method of a trial and hand-fit matching the brake drum surface. Remarkable the difference in how well they perform vs. just installing out of the box.

I would not try to toe in Mafac brakes. As stated, you would be bending the entire arm-not a great idea.
From one of the previous posters, I had totally forgotten the infinite 'Howl" that would occur when you hit the brakes hard, especially when the bike had steel rims with serrated sides. What a howl !!

Park used to make a tool specifically for bending cantilevers/center pulls to toe them in.