Saturday, July 26, 2008

On Small Versus Large Cyclists

If you're a teeny weeny cyclist, forget trying to excel in time trialling. Get to the mountains! Read on...

At very slow speeds in climbing (on the order of 16 km·hr-1 or less) air resistance is negligible, and drafting becomes nearly meaningless. This shift in forces causes the peloton of a road race to break up, as those cyclists who have the highest aerobic power can outdistance less aerobic competitors who are now deprived of drafting derived assistance.

An interesting aspect of this shift is to note that smaller cyclists generally excel on hill climbs, while larger cyclists are generally better on solo efforts on level ground. As a consequence of scaling geometry, mass increases with the cube of height, while surface area only increases with the square of height. This means that, although larger cyclists have a greater total frontal area to push through the air than smaller cyclists, their advantage in mass (and power generating capacity) is even greater. As a consequence, large cyclists have a higher ratio of power to frontal area than smaller cyclists, giving large cyclists an advantage in overcoming air resistance, as observed in time trials. It is not surprising that Miguel Indurain, the pre-eminent time trialist of the 1990's, was larger than most of his rivals.

- David P Swain, Wellness Institute and Research Center
Old Dominion University, Norfolk, VA 23529-0196 USA

1 comment:

Anonymous said...

You're just noticing this now?