M95* bb bearing details

[FST4RD]

I've come across an M950 bb, the perfect one for my build, however it's missing a bearing race, one of the inner ones that butts up against the lip of the axle.
I've been reading topics on here about how they are rebuildable, but not what you need or where you can source parts from.
Does someone have the bearing sizes and an exploded diagram or details on how to rebuild?
Thanks

 

[FluffyChicken]

Re:

The exploded diagrams, at least two versions, are on the forum. Just Google image search BB-M950

 

[FST4RD]

Re:

Thanks.
One of my mechanic friends reckons that, if you machined the axle between where the crank fits furthered onto, to where the lip is for the bearings, you could fit bearings from a square taper bb and use the housing from a rebuildable bb like a raceface one.
Had anyone modified an xtr bb to do something similar to this?

 

[FluffyChicken]

Re:

Why bother?
Just get some bearings.

Now I can grab links easier viewtopic.php?t=175480&start=15


But you couldn't use square tapers as the axle are much smaller axles, maybe ISIS size tiny tiny bearing but they are not as robust.

 

[syncrosfan]

The only way to get parts for those is by getting a shot, or ratty, cheap M950 BB and cannibalize the parts from it. I happen to have one (almost complete, one seal cap is missing, the cups have been mangled by some ham-fisted twat). Both bearings races are there though (some brinelling on them but they work). You can't use a regular bearing on them because the diameter of the axle is that much bigger than a regular square taper and machining down the axle isn't an option due to the fact that it's actually pretty thin walled. On the plus side, the M950 BB is significantly lighter than the sealed bearing M952 one (something like 80 grams lighter, it was the lightest steel axle BB on the market back then). On the down side, the tiny bearings inside a a real pain to work with, the seals are crap, so don't plan on using it in wet conditions (luckily I'm in California).
Let me know if you're interested in it I can send you some pics. (shipping might get kinda expensive to New Zealand).

 

[FluffyChicken]

Re:

Just to confirm is it the ball or roller bearing? Not that I can help.

 

[syncrosfan]

The M950BB has both: needle bearings for the main radial loads, and loose (tiny) cup'n cone ball bearings (inside of the needle bearings) for the axial loads. Sounds good in theory, not so brilliant in the real world.

 

[FluffyChicken]

Re:

Mines working fine still, I was just wondering which bearing race or cage was needed.

 

[mattr]

I've got two, both extensively hammered, both in good condition. The DA is currently in my CX bike, after 8 or 9 seasons use in either my or my wife's road bike, then a while in storage.
The XTR did a similar amount of work and is now back in my retro, which is where it came from.

 

[FST4RD]

Re:

Well I went back to the shop where I came across the M950 BB missing the push on shim race piece. Went hunting through a huge container of random bb bits and pieces from bbs of all types, just as I was about to give up I found it!
Put it on and it's going perfect!
Total win!