RPM Wheelie Bar (Low Visibility) X-Maxx (Only with RPM 81762) - 81582RPM Low Visibility Wheelie Bar for X Maxx Quick Notes: Protection for the low hanging rear bumper of the X Maxx Works with RPM 81762 Rear Bumper Mounts only (sold separately) RPM Low Visibility Wheelie Bars are designed to take the stress off of the low hanging rear bumper whenever the rear end wants to drag on the ground. The wheels we designed are large enough to touch down before the rear bumper does in 99% of normal acceleration wheelies,