For me, its #1 and #3.
There is a lot of motion, and emotion, in the first shot. It has a real sense of speed about it. Nice capture.
The third, I love the angle and almost desperate facial expression, but I don't know that the B&W works in this shot. The rider really doesn't 'pop' from the rest of the image. I think its a combination of a fairly deep DOF and distracting background. Maybe this would work better as a selective desat photo? That would depend on whether or not the rider had one predominant colour or not. The rider in the fourth shot would be perfect for that treatment.
All round though, some very nice shots.