Originally Posted by
Wilfred Laurier
when a heavy wheel is being ridden at a non steady state
like when standing to climb
the amount of extra exhertion required due to increased angular momentum
is minimal
most likely imperceptible
the only reason i can think of for a delta between the heavier wheel requiring more energy to accelerate
than the amount lost in deceleration
would be the fact that the drivetrain responsible for transfering leg energy into rotational energu
is not 100% efficient
otherwise
the extra energy required compared to a lighter wheel
is exactly equal to the difference in deceleration between the light and heavy wheel
To do a reductio, one could hop up stairs, alternating legs, and taking exactly the same time as required to climb the stairs smoothly. Total energy required is the same, yet by hopping one reaches the top of the stairs much more tired, because one's peak output was higher. When it comes to muscular output, "energy" is not the same as classical physics implies, due to the cost of its production.
Racers, and not only sprinters, have always paid a lot of money for lighter wheels, even though UCI limits total bike weight. It's possible they know something.
In real life, the fact that the difference in difficulty of acceleration may be imperceptible, doesn't mean it doesn't exist, or have an effect over 20,000' of climbing on a brevet.
OTOH, I have always gone for aero over light weight, finding that makes a larger difference. Helium wheels were popular for a while, but one doesn't see them any more, now that light aero wheels exist. It's sort of a similar situation with aero wheels. Not a lot of difference in watts absorbed at brevet speeds, but there is some, and it adds up. First brevet finishers are usually on a light bike with light, aero wheels.