This question got me wondering about self-extracting cranks: What bottom brackets are compatible with Miche Evo Max cranksets (self-extracting type)?
Where I've seen them on cartridge bottom brackets, I take it for granted that the crank bolt tightens the crank onto the splined axle and helps hold it there (i.e. 40Nm torque).
But, how is the crank held onto the axle, are the splines tapered and holding everything together (once it's on, it's on), or is it reliant on the crank bolt keeping it together?
Secondly, with external bottom brackets (or press-fit), how is bearing preload managed for self-extracting cranks? Seems to me that once it's on, it's on, it won't go on any more! if the spacing between the cranks is off just a bit, I don't see how it gets adjusted (maybe spring washers?)