It's about double.
Power is roughly proportional to velocity cubed:
P2/P1 = (V2^3)/(V1^3)
= (25^3)/(20^3) = 1.95 ~ 2
(P1, V1 are the power and velocity respectively at 20mph. P2, V2 are the power and velocity at 25mph)
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Cat 2 Track, Cat 3 Road.
"If you’re new enough [to racing] that you would ask such question, then i would hazard a guess that if you just made up a workout that sounded hard to do, and did it, you’d probably get faster." --
the tiniest sprinter
Last edited by Brian Ratliff; 09-27-10 at 09:56 AM.