Originally Posted by
grolby
Nope, it's not that important in crits, either. The difference in the power needed to accelerate wheels with heavy rims vs light rims, if you hold the total weight equal, amounts to fractions of a watt.
Which makes sense, if you step back and think critically for a minute. When you accelerate a bike, you are not spinning up a pair of 1400 gram wheels. You are trying to accelerate your 150 lb butt up to speed. Rotating mass has some influence, but it is very slight. The biggest factor by multiple orders of magnitude is how much torque you can produce.
Lets say one could accelerate at 500w while weighing 70kg (total) this gives a power to weight ratio of 1kw:140kg (.5:70). If you dropped 1 kilo, you would get 1kw:138 (.5:69) or the equivalent of gaining .015kw (15w), this being at 500w. But losing mass of something rotating is like loosing more static mass (I have heard loosing mass on wheels is like loosing 4x mass of total). So possibly 60w difference of 1kg weight loss at the wheels, at 500w original.