Sport Rider Photos
The three forces all act on the swingarm at the rear axle, and their moments about the swingarm pivot can be calculated. As the rear suspension compresses, the geometry of the force diagram changes--sometimes significantly. Note that while the chain pull always creates an antisquat tendency, the driving force torque changes from antisquat to pro-squat as the suspension compresses and the swingarm passes horizontal.
Motorcycle Art And Science