They pop up at eBay once in a while and they are usually very afordable...something like 15 - 17 bucks, sometimes even cheaper, NOS. The CLB made BB shells on the 979s and the Carbone bikes just have a hole at the bottom for the BB shell in which a short stem with a very slight mushroom head on it (IIRC) on the guides pop into. No screw is required to mount them. The tension from the derailleur cables mostly keep them on.
Chombi
Last edited by Chombi; 08-08-12 at 11:52 AM.