Hi,
If you were to use a double ring set up what size chain rings would you use, old set up is 22t and 36t. I’m about to fit a new crank also. My new but second hand frame has a X type BB. If im buying a new crank, will the internal diameter of the BB match any crank on the market? ie race face atlas chainset.

an X type BB is from race face so will fit the Atlas. Shimano use the same BB axle diameter (or rather the shimano is the std). I also use an FSA crank and quite a few others are to this std.

I think it is only the FSA mega exo which is not the std external BB.

i see, thank you,