There are several differences beyond the bearings. These are some basic descriptions, others may be able to better clarify them.

Mainly, the BB30 crank will have a wider and shorter spindle.

The BB30 spindle is 30 mm wide compared to about 24 mm for a regular crankset.

Secondly, the BB30 spindle will be shorter because the bearings are built into the frame, narrowing the distance between the crank arms. With the GXP version, the outboard bearings necessitate a longer spindle. This increases the Q-factor.

You will need a BB30 built frame and your Super Six should be BB30 compatible. If you decide to go non-BB30, you may need an adapter. Wheels Manufacturing has an interesting one that is easily removed.

Lastly, Velonews did a test comparing BB30 vs. non-BB30 cranks and found a almost negligible difference in stiffness.


I hope that helps.