The Expedition Rack Tall Boy was developed to fit the larger wheel and tire combinations that are available. If you just need extra room for a fender or you are running 29er wheels this is the rack.The rack of choice for cyclists who require exceptional durability and expanded size, measuring a full three inches longer than our standard rack. Built from 3/8" 6061 aluminum stock, the Expedition Rack is intended to be used primarily with our Large Mountain and Expedition Panniers where additional rear clearance may be needed for large loads. However, the Expedition is also a good choice when more room is needed for carting the evenings firewood or portaging large containers of water. The secret to this racks tremendous strength is a third support strut which angles back 21 degrees from the main load bearing strut. In addition, the rear support strut offers a 6" long section for attaching the lower portion of your panniers suspension system to enable precise positioning of your load. All stress points are double-welded.