Hi all,
Due to having a few problems with my left crank arm coming loose all the time (Truvativ Isoflow, square taper) I'm considering changing the whole set up.
I've been looking at hollowtec type cranks, and the compatable BB's, but my bike currently has the non-external bearings set up.

I have a 68mm frame.
Can I change the set up, and if so, do I only need the crankset and BB?

Thanks