Excellent capture, and the shallow depth of field here works to bring out the front rider (of these two anyway). Of course, it would be better without the peple standing behind, but there's little you could do here. Maybe at least crop the very top, where the fellows hand is, that' being lighter it stands out.
Super sports photography! YOu capture both the competitiveness and the expressions on these bikers. use of depth of field is very, vey nice and effective. 9
Nice close look at the rider, but I feel as though this isn't a very intense part of the ride, the expression on the boys face isn't particularly intense, his muscles are completely bunched up, there is not mud flying up in the air... it's almost too clean to be a really great sports photo. Facial expression is VERY important for sports, but also the sense of the moment rather then just the clearest photo of any point in the race.