I'm not going to argue every point here, but I hope this picture clarifies this business about about parabolic trajectories and a wheel not really going into a hole as those with "vivid imaginations" might think it would
Originally Posted by
invisiblehand
Interesting. As you know, I am neither engineer nor physicist. Just from rejurgitating common lore, I have been telling people that small wheels accelerate faster. So where the mass is located has an effect on acceleration; but whatever advantage a small wheel has is offset by the amount the small wheel has to accelerate to keep up with its larger bretheren.
They may be accelerate faster if they are lighter. A pair of 700c Marathon Racers are 280 grams heavier than a pair of 406 Marathon Racers, which for the purposes of acceleration are equivalent to losing about 1-1/4 pounds off the frame.
Originally Posted by
somnatash
I also would say that in general fatter tires are not faster than slim ones. Rolling resistance and "air resistance" are important for speed. The faster the speed, the more air resistance gets important and the less important is rolling resistance. In road bikes (which are fast) the air resistance the the more important factor and of course slim tires have less air resistance than fat tires.
plus, the probably more important factor is, that fatter tires are (all else the same) heavier than slim tires. Weight slows you down. So these factors are reason for slim tires in road racing bikes.
Yeah, but all the same could be said in favor of smaller
diameter tires too (lower air resistance, lower weight, etc).