peterwright said:If you compared the power necessary to maintain say 40kmh of a rider of Boonens weight to a rider wieghing 53kg maintaining the same speed the two numbers would be significantly different.
No rider can sustain +8w/kg and many smaller riders can hold onto the pace of a bigger and stronger rider on a flat road. Weight is very relevant in determining what power output a rider needs to maintain for a given speed - flat road or not.
Given - that the more the road climbs the more weight becomes a factor but on flat roads it still has a significant bearing.
The two numbers would not be significantly different. Try analyticcycling.com
Using a flat road with the given atmospheric conditions and rolling resitance, a cda of .315, and a weight of 63 kg rider +bike for rider 1 I get 292 watts to go 40kmh.
Using the same conditions but a rider+bike weight of 92 kg, I get 304 watts.
If we take into account that a smaller rider will generally more aerodynamic, I dropped the cda of rider 1 to .28 and get 275 watts at 40khm. Hardly large differences.
Smaller riders can often hang onto the pace of bigger riders in a pack, at a hugely reduced workload due to drafting. Not many 55kg riders have won Paris-Roubaix, Flanders, or big tts because these require efforts on the flat without such a draft benefit.