Cycling is an interesting sport in terms sof the body-types and the shapes and sizes that do well in it. I suspect that this is because it is non-weightbearing and that there are mechanical levers involved in the muscular action that drives the bike forward.
There is definately a range in the size and shape of the top riders compared to a sport such as distance running where pretty much all of the top runners are small and slight. (Just about all the top male runners in the world are less than 5'10 and less than 115 - 120 pounds). That being said one does associate certain body-types within cycling with their specialties. As expected the sprinters are typically bigger men, but not always. And don't forget that these guys can only be involved in the sprint at the end if they can hang-on for 4 - 5 hours to make it to the last few K's - that's definately endurance aerobic work there. The pure climbers tend to be the smallest and lightest as one might expect. Time trial specialists are typically bigger men, but again there are exceptions here( Chris Boardman, Tylar Hamilton). All Rounders, who are the the ones who are typcally challenging for the lead in GC at the big tours have a middle build and I would think that Lance Armstrong personifies that - not small and not so big. Too put some numbers on it close to six feet tall and 150 - 160 pounds.
Steve Fleck @stevefleck | Blog