fitting mavic ssc sealed b/b - help pls?

SJLcp

Hi

I am fitting a NOS MAVIC SSC sealed b/b to a vitus 979 frame - this b/b doesn't screw in but has tapered ring nuts that fit into the frames alloy shell - which is already faced with tapered ends

Question is do I use the thin plastic washers that fit between the shell and the rings? This would cause the nuts to overhang the end of the b/b - missing them out would make it all fit together perfectly? Also do I just nip the rings up or really wind them up bloody tight? Haven't used this type before so all help appreciated

Many thanks!

synchronicity

I remember reading about this BB as a possible fix for stripped or cross-threaded BB shells...

BBs generally need to be done up tightly, don't they? :?

If it fits better without the plastic washers, I'd leave them off & just trust that a good smear of high-quality grease would be enough...

SJLcp

Hmm - well the next problem is my lockring spanners don't fit around the locking rings (old fashioned six indented ones) - I am going to have to buy a pair of C-spanners

proto

If I remember correctly each lock ring has a 45° taper/chamfer on one side.
The frame has to have bottom bracket shell prepared by machining a similar 45° chamfer at the mouth of the thread, boty sides, quite a big chamfer too, possibly as much as a couple of mm.
When, I say machining, a hand tool used is very similar to that used for facing a standard BB shell, but with a different cutter.

When tightened the lock rings then locate the BB in the centre of the BB shell.

Bike shops usesd to have a special cutter for doing this. Might be best to talk to a big shop with a tradition of selling racing bikes about the tool/cutter.

Personally I'd do the lock rings up very tight. And/or use some Loctite threadlocker.