Just looking at these makes me want to get back on my bike. Unfortunatly I am 2 hours away from home at college with a CR250 collecting dust in my garage. These pictures are great man, I can see the 3rd shot being on the front of Transworld Motocross. The 4th pic of the Berm shot is great to, Next time you get out there and watch your buddies ride, try and get a shot of him roosting the **** out of the berm with a serious amount of dirt in the air. Great job overall man.
Not bad, I think you are using too fast of a shutter speed and have too much height in the top of your shots. You might want to consider adjusting you EV to control the white blowouts of the uniform.
Just my 2¢.