New develop constant velocity roller axle (CVR) Design to give ultra smooth, higher corner and less tear and wear. The CVR come with stock replacement outdrive to replace the original gear diff outdrive to CVR outdrive. CVR uses roller bushing to eliminate the friction from the old horse shoe plastic design. which in turn created a better and smoother drive tran. With option Bearing Replacement for the bushing, racer can increase the drive tran efficiency even more.