Oh well. I always thought it was more interesting to figure out why things work, rather than just knowing that they work. Heavier wheels don't necessarily mean poorer performance, cause it depends on WHERE they are heavier. I haven't yet figured out how to fold all of the rotational inertia (the resistance the wheel has to turn) into how that affects actual straight line acceleration. I tried it once, but wound up with some really screwy results (an equation that describes accleration reduction factors tied to rough wheel weight). Oh well, next time I have some time to kill, maybe I'll try and figure that one out...