While it is known mostly for bicycles, Giant also produces a host of bicycle components and accessories. Giant's racks come in two basic designs. The Rack-It Disc is designed especially for a bicycle with rear disc brakes, while the Rack-it Beam will attach to any bicycle seat post between 24.4mm and 31.8mm. Both rack designs are compatible with most Trek bicycles.
Align the eyelet tips at the bottom of the rack with the eyelets on your Trek bicycle frame. The eyelets on the frame will be near the axle of the wheel.
Determine the proper length of each rack leg. Ultimately, once installed, the surface of the rack should be parallel above the tire. To lengthen the legs, loosen each Allen bolt just above each leg tip. Once proper length is achieved, re-tighten the Allen bolts.
Insert an included Allen bolt into each eyelet at the bottom of the rack, and tighten the bolts against the bicycle frame.
Determine the proper length of the upper arms of the rack. These arms attach to the upper portion of the frame seat stays. To lengthen or shorten the arms, loosen the bolts that allow the arms to slide back and forth. When proper length is achieved, re-tighten the bolts.
Insert an Allen bolt and washer (if included) into the eyelets at on the upper arms of the rack. Tighten the bolts against bolt holes in the seat stays on the bicycle.
Open the quick-release lever on the arm of the rack. This will loosen the clamp.
Slide the opened clamp against the seat post of your Trek bicycle. The rack should be high enough so that it does not interfere with the wheel.
Close the quick-release lever on the arm of the rack.