Aardwolf

Hiya Folks,
I'm probably in the market for some Mafac Racer brakes, but I need the longer ones I think - I need about 65mm for the front brake.

I've done some research - they came in 3 reachesBut what I don't know is how to identify them visually (eg. in an advert).
I've seen some comments say there's a number on the back: 451 = small, 452 = large, 1451 = adjustable

Can anybody confirm this and suggest any other visual differences please.
Cheers.

bulgie 

I'm pretty sure the two main arms are identical for all three, and the only thing that varies is the back plate that holds the pivots (Mafac calls it the étrier).

Sorry I don't know how to tell large and small apart without a measuring device; hopefully someone else will chime in here.

The adjustable one is easy to spot though; the hole for the center bolt is an oval slot, not a round hole. Worth noting, if you adjust it down for long reach, the étrier will impinge on your fender clearance. It's not an elegant design for those who use fenders.

Mark B

Charles Wahl

Mark is correct; MAFAC variation of reach is accomplished by the étrier. Good luck finding anything with "grand" étrier; however, I believe that the Racer, Competition, '2000' and 'S' all used the same arch, so if you can find any of them with the longer reach, you'd be OK. All of them except the Competition go to 68 mm with the grand étrier. You're right about the part numbers, though I'm not sure those are stamped on the arches.
while I like MAFAC brakes, I think that the Weinmann's approach (having shorter or longer arms to effect reach) is more rational, though it messes with the mechanical advantage a bit (OK if it's the rear, as is most commonly the case).


For the whole poster:
https://www.flickr.com/photos/131757...7628023244738/

Aardwolf

Thanks for the link, first time I've seen the full poster.

Some of them do have the part number stamped on the bridge, but I'm only seeing '451' currently



It looks like some sellers do know about reach - "mafac racer long" has 4 matches on Ebay at the moment.

Think I'll wait until I can do an accurate measurement of my required brake reach.

robobike316 

Excellent info in the above post, particularly the poster! The definitive answer-directly from Mafac themselves.I have had some Racers with numbers in the casting and some without, when in doubt just measure or just put em on the bike. If they reach they reach! If they don't find a longer backing plate or etrier as the French like to say. They've got a different word for everything, don't they!

bulgie 

Brazed-on pivots is another option, excellent in every way except economical - it's not. Unless you want to get into it yourself, which is do-able for the home mechanic, but just be really sure you brazed them on well. The stakes are high. Getting them properly aligned can be tricky too. If the posts aren't completely parallel you can get one arm rubbing on the other one. (That can't happen with cantilevers, which is why canti posts are a bit easier.) The jig to hold the posts parallel while brazing can be just a piece of steel with two holes in it, nothing too fancy needed.

For most people whose brazing skills aren't up to something so safety-critical, you're looking at sending F&F to a framebuilder or mods specialist like gugie and then repainting afterward. That could mean some rattle-can primer sprayed on just the burnt areas, but a full pro paint job is $$$.

I don't know what Gugie charges but I'd guess for most pros it'll be $150-$250 for F&F. Unless you know a good amateur who will do it for a six-pack and a pizza? You can ask on the framebuilder subforum, or maybe you know who the FBs in your town are already.

Advice for DIY-ers can also be found here. scarlson has posted tips, and the Frek story from lonesomesteve is inspirational. You might even end up using Raids instead of racers and converting to 650b for a taste of "the supple life".

Mark B

oneclick 

With something to compare to, it's not hard. Though there are doubtless variations, on the short versions the arc of the lower edge of the etrier stamping is usually flatter, and the curve into the boss eye is tighter.

See especially the last in this post:

https://www.bikeforums.net/classic-v...stampings.html

Aardwolf

Cheers, I think that post shows that relying on a marking isn't going to wprk unless it actually has '452' on it.

Kabuki12

I have one bike that came with Mafac Racer brakes and when I got the bike it had 27” wheels and after about 5 years found a very nice set of vintage 700’s for it . The brakes adjusted down easily without limiting out. They stop very nicely without having to bear down on the levers . A bit more adjustment so it takes a bit longer to set up properly but I love them.

Aardwolf

Yep, I'm hoping to like them.

Currently using Weinmann 500 sidepulls, but my new 1961 Holdsworth Cyclone probably came with Mafac Racers.
From the 1961 catalogue:

Charles Wahl

Here's a photo of all three types of Mafac étriers* from the rear, from left to right, petit, grand et réglable. In truth, I find it hard to distinguish the first two (non-adjustable) types by eye, though if they're put back-to-back it's easy enough to see the difference in height. But note that the little hole to receive the end of the brake spring is about 1.5 mm from the "break" in plane on the petit, and closer to 3 mm on the grand. And a line between those holes is at about the same height as (or very close to) the underside of the arch apex on the petit, but clearly below that apex on the grand.
*étrier in its most common French usage = "stirrup".

EDIT: Having stared at them a bit more, it's clear that the middle of the arch is a lot flatter on the petit, and clearly more curved on the grand. And the inside profile of the end parts where the post is swaged in is more inclined toward center on petit, and more "vertical" on the grand.

Of these 3, only the petit has the part number (451), but that could vary depending on date of manufacture (though the petit and grand shown here are from the same brakeset). Several MAFAC Competition brakesets I've bought have had one each petit and grand.

Aardwolf

Many thanks, that's the sort of info I need.

Even an idiot like me can see if a line between those 2 holes is above or below the bottom of the arch.