lol, if you wanted to get way too complicated with this, you could explain it with some physics. Really the acceleration of the wheel comes down not only to the weight of the wheel, but of the shape. Its better if you can find a wheel where most of the mass is concentrated closer to the middle of the wheel, i.e. no fancy weird lookin spokes, because it lowers the moment of inertia of the wheel (anyone here in engineering or with some sort of rotational dynamics background knows what im talkin about) So while a light wheel is the preferred way to go, the shape of the wheel is also important.