[Max Lobovsky]

Yes, Sanddrag, you can certainly clamp a gear on the CIM shaft safely. We, and many other teams have done it. I think clamping is one of the most under used ways (in FIRST) to attach stuff to shafts. I wish I had some numbers, but from my experience, except when it comes to moving arms or other extremely high torque stuff (and maybe even then with a sufficiently large diameter shaft/collar), everything can be clamped on a FIRST robot.

I have also heard it recommended to use extra-strong loctite when clamping to improve the amount of torque you can transfer. Personally, I just make sure the metal surfaces are clean, maybe wipe it with rubbing alcohol.