I've got a 49cm Motobecane Track with a bent fork. A friend of mine has the fork from his old Cutter Bones (his frame is larger, not sure by how much). The headset on both bikes is 1.125", I'm wondering if his fork would be compatible with my frame? And if so, how much (if any) difference does it make that his frame is larger?

if his frame is larger and he is taller, then you may have to trim it down some or buy more spacers but I would think it'd work.

It will work, just the steerer tube will be longer most likely

Guess I'll be the only one to ask about rake and axle to crown length.

How do the rake and axle to crown lengths compare between the two forks?

It'll probably fit your frame, but, if the axle-to-crown height isn't the same between forks the handling will change.

DO EEEEET!