Originally Posted by
asgelle
How is ignoring rolling resistance splitting hairs? There are two terms in the equation of motion that scale with mass: 1) the driving force due to gravity, and 2) the ******ing force due to rolling resistance. How can you justify including the first, but ignore the second? Perhaps you meant changes in the coefficient of rolling resistance which will depend on tire size, construction, and inflation pressure; but not on weight.
I am pretty sure that rolling resistance is not much of a player in this situation. Feel free to prove me wrong. But I think it's a reasonable assumption to get a ballpark estimate.