These flexible urethane torsion spring spacers add pre-load to the rear torsion springs and eliminate the twist to allow the spring to function efficiently. This increases the compression rate help with sag and ride height. They also give your rear suspension a more solid predictable fee. They are a must have for aggressive riders. And also benefit heavier riders. The G5 bushings fit both the traditional T-Motion X & the Rigid T-motion XT rear skid.