Originally Posted by
jolly_ross
I am unable to convince the heavies in my cycling group of this (possibly because I'm wrong) but here goes: being heavier does not make you descend faster. If you are 10% heavier (say) then there is 10% more gravitational force between you and the earth - but the thing is this is *exactly* offset by there being 10% more inertia for this force to overcome. .
I like the way you're reasoning.
That would make perfect sense in a vacuum. Feather and a rock would fall at the same speed (in a vacuum). However, in the real world with air drag, heavier rider (all other things being equal - road, bike etc) will descend faster, because extra weight is not negated with (that much) extra wind drag.
Logic behind this is: at downhill speeds wind drag is a lot more significant resistance to overcome than inertia.