Back anti-roll bar for ball-bearing roll bar mounting system and redesigned to utilize the X4 rear suspension arms. The anti-roll bar system is mounted toward back bulkheads via bearings from outside for extra-smooth motion and for fast & simple modifications and adjustment. The roll bar turns in ball-bearings for optimum accuracy and free movement. Anti-roll club height is adjustable via a screwââ¬Â¦ fast & simple. Anti-roll club has laser-engraved stripes (corresponding to bar thickness) for simple identification.