Motorcycle horizontal acceleration--front wheel rise The distance between the centers of the wheels of a motorcycle is 171 cm. The center of mass of the motorcycle, including the rider, is 95.0 cm above the ground and halfway between the wheels. Assume the mass of each wheel is small compared to the body of the motorcycle. The engine drives the rear wheel only. What horizontal acceleration of the motorcycle will make the front wheel rise off the ground? 2. Relevant equations τ=rFsinϕ I understand that the solution is when .95ma=1.71/2(mg), so when the torques are set equal to each other. why though? thanks!