Why not just hand the title over to the person with the highest Vo2 max?

[Azdak6]

To answer the OP's question: VO2 max is not the best indicator of performance in cycling. The best predictor of performance is sustainable threshold power per Kilo of body weight AKA sustainable power to weight ratio.

Still, just a good power output at threshold does not take into account bike handling skills, tactical decisions, cornering skills, descending skills, mental toughness, etc. All fun things to watch in a bike race, not to mention crazy luck, weather, and other intangibles that make the race such a cool drama that cannot be recreated in a lab.

VO2 max just puts you into a general physiological "pool" which includes those who may be able to develop their abilities and talents to become world-class. As you state, power output at threshold just shrinks the pool, so that the other factors become more significant.

 

[Alex Simmons/RST]

To answer the OP's question: VO2 max is not the best indicator of performance in cycling. The best predictor of performance is sustainable threshold power per Kilo of body weight AKA sustainable power to weight ratio.

Actually the best predictor of performance is performance itself.

Sustainable aerobic power to weight ratio is the best physiological indicator of endurance cycling performance.