Yakima Copperhead Fork Mount Bicycle Carrier for Sale. Fits both round bars and square bars. Used, but in good condition. Below is info from the manufacture... The Copperhead is a fork mounted bike carrier for Thule (square) and Yakima (round) crossbars. Its aluminum construction in both the head and 42-inch tray provides a sleek, low profile tray design. Includes a long-throw, quick release that provides excellent security and durability. The rear bike tire is secured by a nylon ratchet strap that is adjustable and fits road-bike tires and up to a 2.3 inch mountain-bike tire. Comes complete with all mounting hardware for quick and easy installation.