The BrassKnuckles is our premier upright or wheels on rack. Lift the bike into the alloy wheel tray, ratchet the arm down, secure the wheel straps and you are ready to go. Our goal in making the rack was to hold your bike securely, keep it simple, fit all crossbars, maintain a low profile while not in use and make it easy to use. Mission accomplished. Rubber coated stainless steel straps secure the mounting head to your crossbar for a clean look, the wheel chock folds into the head for a graceful look when not in use.