The motion ratio is the distance between lower control arm bushings to the centerline of the spring divided by the distance from the lower control arm bushings to the ball joint.
It represents the ratio of shock travel to wheel travel. Wheel rate is (motion ratio)^2 times the spring rate.
In the rear suspension, assuming the springs are mounted on the rear end, the motion ratio is about 1:1, so the spring rate equals the wheel rate.
Hope that helped.
__________________
Ken
|