@Cranky, u-shaped disc locks are for locking non-deep-rim wheels to the frame. Or, depending on the size of the gap, also including part of an iron fence.
I'm not sure I understand which rotor you mean would be cut.
The U-shaped disc locks I've seen on motor bikes seen to prevent motion by locking the disc brake's disc. It is the disc I was referring to; sorry I probably used the wrong terminology.
Wouldn't a bike need very, very tight clearances to use one of these locks?
@Cranky, u-shaped disc locks are for locking non-deep-rim wheels to the frame. Or, depending on the size of the gap, also including part of an iron fence.
I'm not sure I understand which rotor you mean would be cut.