Bike carriers for the car must withstand a serious load and most styles are nearly impossible to manufacture without metal parts and the knowledge of how to weld them. However, simplistic one or two bicycle rear-mounted racks for use on vans, sport utility vehicles, minivans, hatchbacks and any other vehicle with a flat or only slightly curved rear end are easily constructed of readily attainable materials. These racks are, according to Consumer Reports, one of the least expensive styles available, but the savings can increase even more if the rack is built at home.
Hold one side piece of wood and the top support piece of wood to form an upside down L and drill three guide holes through the side piece and into the end of the top support piece.
Screw three screws through the side and into the top to secure the upside down L shape.
Repeat guide hole and screw insertion at remaining corners to create a rectangular frame roughly 24 inches tall and 20 inches wide.
Hold the corner of one bike support piece of wood to the top corner of the frame so the grooves in the support piece are on the top (point to the sky) and farthest away from the frame, then drill three guide holes through the support arm.
Screw three screws to attach one bike support arm to the top of the rectangular frame extending away from the frame.
Repeat steps 4 and 5 to attach the second bike support arm at the remaining top corner of the frame. Both arms should extend away from the frame and have grooves at the top of the arm as far from the frame as possible.
Insert the remaining 18 inch long arm support piece between the arms roughly four inches from the frame and drill three guide holes through each arm and into each end of the arm support piece for a total of six guide holes.
Screw six screws, three per side, into the six guide holes.
Hold one angle cut brace piece against the bottom of the arm and the frame back to create a triangle and drill two guide holes in each end of the brace through the thickest part of the angle cut and into the material behind.
Screw four screws through the brace guide holes.
Repeat steps 9 and 10 to attach other angle cut brace piece to the bottom of the other arm on the other side of the frame.
Cut length of garden hose in two sections of 20 inches each and four sections of three inches each.
Glue two 20-inch sections of hose across the back of the frame at the top and the bottom parallel to the ground to protect the vehicle finish. Allow glue to dry completely before use.
Glue four three-inch sections of hose in grooves cut in the arms to protect the bike finish. Allow glue to dry completely before use.
Cut length of polypropylene webbing in six equal 4-foot long sections and use matches to seal the ends to prevent fraying.
Loop two inches of the end of one section of webbing through a metal flat hook and sew the webbing together so it is attached firmly to the hook. Stitching must hold the weight of the loaded rack to the vehicle and must be very secure. Many types of stitching will work. Suggested stitching is a 1-inch loop stitched square box with diagonal loop stitched cross pieces.
Repeat step two until all six straps have a metal hook attached to one end.
Repeat the stitching method of step 2 to attach a metal cam buckle to the opposite end of one strap from the metal hook.
Repeat step 5 with two more straps so three total straps have cam buckles and metal hooks attached at opposite ends.
Hang one strap without a buckle in the middle of the desired mounting surface by a metal hook. Attach the hook to the boot or hatch lip.
Hold bike carrier against rear of the vehicle and lift strap over frame, then attach the hook end of a strap with a buckle to the bottom of the boot or hatch lip.
Thread loose end of the strap hanging down into the cam buckle and tighten straps almost completely.
Repeat steps 1 -- 3 to attach a second set of vertical straps.
Run remaining two straps horizontally through the triangles created by the frame, arms and braces and thread the cam buckle then tighten this strap most of the way as well.
Move the two vertical straps as far apart as the arms will allow and snug down. Be sure carrier is located in desired position before tightening all the way.
Snug the horizontal strap down.
Load one bike so the arms support the top tube of the frame and wrap two old toe-clip straps snugly around the frame tube and either arm to attach the bike to the carrier securely at both arms.
Repeat step 8 but face bicycle so the rear wheel of the loaded bicycle hangs next to the front wheel of the second bike.
Check all attachments and snug all straps a second time. Check straps once every half-hour of travel to ensure no slipping is occurring.
Varnishing or weatherproofing the wood in some way will extend the life of the bike carrier. Old and new toe-clip straps are easily obtained from a local bicycle shop. Bike car carriers also make an excellent bike work-stand in a pinch. A sewing machine will make all stitching far easier.
Attempting to load more than two bicycles on this style of rack is unsafe. Wet weather conditions may cause straps to stretch and sag slightly. Over-tightened wet straps may damage vehicle or carrier when they dry.