Originally Posted by
kbarch
Sure, anyone with flat knobbies and grit-filled hubs is going to have a hard time keeping up with anyone on a slick bike,
but in this case who's to say which rider has equipment with more or less rolling resistance? For present discussion purposes we can assume they are the same for each, can't we?
We can assume they have the same coefficient of rolling resistance (after all that is what is equipment dependent). But for equal equipment, the heavier rider will have higher rolling resistance than the lighter one.