BB conversion help

It is not technically feasible to use a BB30 crank on a bike that has threading for cartridge or outboard bearings. The spindle diameter for the outboard bearing cranks is 24mm. The diameter for the BB30 crank is 30mm.


It is technically feasible to use a crank with a 24mm spindle diameter on a BB30 frame. That's what I've done on my Cannondale Super6 by purchasing an adaptor..

What are you trying to do? Put different cranks on it?

http://www.praxiscycles.com/conversion-bb/
http://www.rotorbike.com/products/road/bsa_38

Actually, you CAN use a BB30 crank on a standard 24mm threading BB… Zipp made threaded BB's for their Vuma cranks, which uses a 30mm axle. Unfortunately, Zipp stopped making crank sets, so the bottom brackets are getting more and more rare…

I'm using a Quarq BB30 crank on my new Pinarello Dogma F8 (with a Zipp Vuma italian BB).

So I can find the zipp vuma quad bottom bracket for $110 which doesn't seem too bad but it says only works with zipp cranks. So it works for you with a different 30mm bb crankset? I might have to buy that, plus get the benefit of ceramic bearings.

I only use it with PF30/BB30 cranks… never actually used with a Zipp crank. :-)

And those ceramic bearings are absolutely amazing! By far the smoothest bottom bracket I've ever used. The only challenge is that they technically require a special installation tool (which is impossible to find…), but if you finger tighten the BB then use soft jaw pliers (non marring), you can tighten down the BB without a problem. Just be careful not to mar the surface (or just deal with a few scratches on it, cosmetic only and doesn't have any impact on the function).