The focus on this one could be a bit crisper, thought obviously with this subject the number of retakes is probably limited. :) Incredible composition and timing to get this one.
While I like this photo and think that stopies are very cool. I rated this photo lower then I would have if it was sharper. I am sure he was moving pretty quick. I would have also tried to position myself to get the rider in back more if it helped or less if he wasnt doing anything but his head above the back seat is a bit distracting.
THis pic is pretty muddy, not focused very well. Exposure is a tad dark but the framing is very good. Unfortunately it looks just a little too low res.
Wider aperture and quicker shutter speed may have helped freeze this one better, which is how I would like to see it...frozen solid, like he stuck that front tire on a dime. the colors also seem a bit bland and "washed out."
Quite a stunt action shot, plus you meet the challenge. The background isn't perfect but reasonably well controlled considering there's bunches of people around etc. The biggest issue you have with this photo is that it is out of focus.