This caught my interest after someone posted the question on a cycling forum of would a heavy and light cyclist have different accelerations down an inclined plane when coasting from a stop. Many people had observed that heavier cyclists do indeed have a greater acceleration, but I wasn't satisfied with any of the explanations. I was trying to figure out why with a diagram and equations but I've failed. I'm thinking that the heavier rider applies a greater torque to the wheel thereby causing a greater acceleration. Is that correct? Anyone able to work out the equation for the linear acceleration given the mass, plane angle, and radius of the wheel? Neglect air resistance. Thanks! PS What's a good explanation for why a wheel rolls downhill, in terms of forces?