jeirvine 

Yes - a hair bigger would be good. I checked before installation, but it was easier to ream after installing on the arms.

bwilli88 

Will these work with Dia-comp Stud mounted brakes?

knucks

No idea, you'd have to check measurements and let me know

CV-6 

I disagree with a hair bigger. I test fitted mine prior and they were good. Once installed in the arms, one arm required some work for free movement while the other did not. I would think it preferable to be a tiny bit snug and work it out than risk a loose fit.

jeirvine 

Agreed. You can always remove, but can't add. And mine was a sample size of four studs from the same brake batch.

79pmooney

This is just my experience, but ... play in Mafac pivots matters very little. They work just fine even with a lot of play. I would replace my calipers oh, say every ten years or so when I happened to find a newer pair but never noticed any change in braking other than a freshly adjusted pair was nice.

Ben

noglider 

I've already been wondering why this thread is so long. It's interesting, but how important is this matter? Oh, this is BF. Never mind.

gugie 

It took me awhile to think of an adequate response. Then it came to me:

Right around DEFCON 2.

knucks

Does anyone want a bushing tool, like Compass sells? I can make one similar for $15 shipped.

unworthy1

One detail nobody mentions (or if they did I sure didn't read it) is that MOST of the "bronze bushings/or bushes for you Brits" are not made of simple bronze (nor simple brass) but are sintered and oil-impregnated bronze. That's what makes them bushings and not just a sleeve. I believe what McMaster-Carr sells (and what I've bought at my local hardware store) are of this material, including some "flat" bushings that look like fat washers, as well as those sleeved-bushings-with-flanges. And the machining properties of oil-impregnated bronze will be 'different', but not having done any lathe-work on them I can't say if cutting is easy, just possible or not recommended.

Edit: went and looked it up and there ARE some warnings to be aware of before you cut sintered bronze, but it IS do-able with proper tungsten-carbide cutting tools and practices, see this:
https://www.nationalbronze.com/News/8...nze-bar-stock/ and this:
https://www.lm-tarbell.com/machining_sintered_bronze.htm

I did hand-ream some myself. Probably the simple bronze (or brass) sleeves that some of our crafty members have machined will work just fine for Mafac brakes, haven't tested them or against factory bronze-bushing-equipped calipers to see.
Delrin and to a lesser degree Nylon both have some "self-lubricating" properties, which is why the French spec'ed that material for bushings and sleeve bearings.

knucks

I am sure the Compass ones are simple and do the job just fine. Add some grease.

Also, I've found some that are what you say in what seems to be proper sizing - I sold a set and hope to hear back soon - I also have two of them in a rear brake.

knucks

I have 20 sets of bushings! pm me thanks

Snook91901

Great thread y'all.

rc93

I'm looking to replace some worn out (what I assume to be) original bushes on a set of Racers. I don't have the facilities to make a brass set, does anyone know if these nylon ones would be appropriate? They seem to be the right dimensions, but I'd appreciate someone with some experience taking a look.

I can't link to their site as I've just joined this forum, but they're from Bowman UK, and the part number is WMGF 08 10 10.

gugie 

Note that most parts are interchangeable between Racer, RAID, 2000, and Competition (and others). The plastic bushings are the same. You can find some models with pressed in brass bushings, but dimensionally they're interchangeable, as far as I can tell.

All the dimensions from Bowan check out except the overall length, but this should work. The pivot post on the backing plate is 11mm long, so the bushing stack can't exceed that, else when you tighten the bolt it the brakes would bind up.

The nominal length of the MAFAC bushing (article 455D, below) is 10.5mm. article 53a is there to hold the return spring in place, and is nominally just shy of 0.5mm, so the stack up is slightly less than 11mm.



MAFAC article 455D is nominally 10.5mm in length, including flange. The Bowman bit is 10mm. Add article 53a in to the stack, MAFAC is 11mm (actually just a tad short of that), whereas the Bowman bit with the same shim on the other side would be 10.5mm, so there would be more play. This could be easily accomodated with a thicker shim, just make sure it's not too thick.

kyleboyd

Sorry for resurrecting an old thread, but I thought this was worth it. I recently lost one of the bushings on my wife's old mixte. As a cheapskate, I was reluctant to pony up the dough for Rene Herse brass replacement bushings (the bike probably isnt worth that anyhow) and I couldn't find any other options. After searching forums, ebay, and striking out, I finally found these on Amazon, simply by searching for 8mm bushings. $6 for a 10 pack. I replaced the two on the brake that was missing, and the worked perfectly. (I used a bolt/nut combo to press them into the caliper, as suggested somewhere on this thread I think). They are more copper toned than the bronze RH ones, but I dont care, you never see them.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

(also kind of posting this to get some opinions - let me know if my wifes bike is going to self-combust due to some galvanic reaction or something)

noobinsf 

Is there play in the connection, or is it a snug fit? I'm curious, because I'd love to have a workable replacement for the red plastic. Thanks for taking the plunge!

kyleboyd

It seems to be pretty much a perfect fit. No play (although from reading through this thread, it sounds like there can be quite a bit of variation between batches of brakes)

…it’s a 10 piece set. I’d be happy to share 4 if you want to be another data point.

ascherer 

If noobinsf isn't interested, I'll check them out.

Dawes-man

Definitely worth it. Thanks for posting. The more info the better.

noobinsf 

Thanks for the offer, kyleboyd! I’m going to think about it a little, but in the meantime, I will step aside for ascherer. If I decide to plunk down the $5 for my own, I’ll share my experience here, too.

Road Fan

Never too late to acknowledge a clever comment!!!

hokiefyd 

Thank you for posting your experience with that. I ordered a set of 10 for myself, and will give it a go with a set of late '69 MAFAC Dural Forge brakes. Mine came from the transition period when they had already moved to the red plastic bushings (from the black), but were still stamping "Dural Forge" into the arms.

ascherer 

I did, and I will. May take some time to get to it…feels like a winter project.

Narhay

I'm about to hit order. I am assuming it is the 8mm x 10mm x 10mm variant.