Can I use any BB with any crank? Specifically, can I use an MTB BB with a road crank (I’m thinking they’ll be sealed better)?

Do I need to get the BB shell faces, erm, faced?

I prostrate myself before the STW oracle.

probably not, I’m afraid – the road cups are narrower than mtb ones and the axles shorter on the cranks.

I think the BB is different twixt road and MTB, not sure if the cranks will fit or not though.

That’s not really much help, is it?

I thought XTR and dura-ace were pretty much the same?

Anyways, the MTB standard is Shimano, RF, FSA are interchangeable. SRAM / truvativ are different.

Road, I just use Hope Ceramics, which seem to be ok.

road ones don’t seem to be that much different to mtb ones, tbh, I’ve used XTR/XT mtb and DuraAce and Ultegra road and other than the bearing sizes/widths the actual seals seem fairly similar all round.

Smashing, I’ll just get a road one.

no, sorry mate, I tried, it didn’t work – the left hand crank is half off the splines.

you edited after my post (and I’m not stalking you!)

CRC

If the Shimano, FSA and Race Face cups are all interchageable, then these are a bargain buy?

those are mtb ones.

and conveniently not all FSA ones are shimano compatable.

Ah sorry, didn’t read the OP properly.

How do you tell is FSA cranks are compatible with shimano b/bs?

“How do you tell is FSA cranks are compatible with shimano b/bs? “

Forum legend has it that you spend £150 on a ceramic FSA BB, use a hammer to try and install a shimano crank, give it to your lbs to sort out and then complain that the BB is damaged when they give it back.

My experience was that the FSA Gossamer axle was about .5mm too fat to fit a shimano BB.

I’m confused by all this. Are Shimano road and mtb HollotechII BBs interchangable (with spacers)?

no, the actual bearing cups are different widths (and the little plastic psacers in the BB of the bike).

The axles on the cranks are different lengths as well…

The FSA BB’s in my Alura catalogue list the ones that will work with Shimano / RaceFace BB’. I think there is only 1 out of the 6 or so they do. I take it you do mean X type BB’s. So Hollowtech are compatable with RAceFAce Evolve/ Ride and Deus. Acros for ceramic, Hope for rebuildable CK for servicable on the bike.

If anyone out there has an expired RF or Shimano BB they want to donate I would be very gratefull. Next door unit has an engineering co whoi want to look into machining a hole ,with an hex keyed plug. Remove plug, fit a grease nipple and lube , remove grease nipple and refit hex plug. SO I need 1 or 2 to unengineer

OK I had a look into it last night, shimano road and mountain bike bearing are interchangeable to a degree. Road ones have a slightly shorter threaded section so if you are spacing out an MTB crank on a 68mm BB shell you might be a bit short of threaded section inside the BB shell. on a 73mm bb you should be fine with either and mtb bearings should go on road BBs fine. Just make sure you use the right spacers for your cranks/BB shell.