The biggest determining factors in ride quality and suspension performance are coil springs. Skyjacker specifically engineered a progressive 2-stage dual rate long travel coil. Spring rate progression is from a 1st Flex Rate to a 2nd Ride Rate. The 1st Flex Rate stage delivers a comfortable ride with the ability to flex for increased articulation. The flex rate expands during full articulation as the suspension drops (full droop). This keeps the coil springs seated in the upper coil mount/bucket and the tires in contact with the terrain. The 2nd Ride Rate stage only engages after compression past the flex rate.