Goody over on the RSR
forum was the one who found out about the 7003C bearing which I think was later changed to the 7003B. Both are angular contact ball bearings and the B is rated at 20,000+ rpms
in oil while the C is rated at 67,000. Probably changed to the B because of price. They are rated for both radial and axial loads. I don't remember the primary ratio but I doubt our clutches see more than 3,000 rpms.
The 6003 that comes in the bike is supposed to be a deep groove bearing but it looks like it has its limits.
The roller bearing in the picture doesn't look like it's designed for radial loads. It does give a good idea how the angular contact ball bearing works though.
The important thing is that it can only be mounted one way.