so the spacers which come with it go between the crank and the BB or the frame and the BB…???

ok, so well behind the times i know, i love sq taper… but needs must. and no destructions with my chainset from crc… quick, tell me!

Frame and BB, how many and where depends on BB width. Google and you will find instructions on which and where.

EDIT click here for shimano instructions (as a pdf)

and whats the plastic tube what comes with the bb for?

Plastic tube goes inside the BB, to stop crap getting to axle, I guess 🙂

Plastic tube goes between the cups inside BB shell. Spacers are two on drive-side, one on non driveside on a 68mm shell (IIRC)

fanks 🙂