Wherein P: Payload DX, DY: Define a location for spring attachment S: is the extended spring length H: is a line perpendicular to S C.: is the arm angle F: is the spring force-K(As)+Initial Force M: moment about point a. The parabolic function as described above produces regular lift. The crank effectively applies a reverse parabolic function to linearize it. Therefore, if a Zero offset is selected, the ride will be hard and non-iso-elastic. (att70° with no offset one must lift 10 lbs or push down with 8). With appropriate offset and geo curve mere ounces suffice at both ends with a single high-rate spring that fits into the diagonal of the lifting triangle.