How to Build Your Own Bike Trailer

How to Build Your Own Bike Trailer
If you use your bike for errands or long-distance touring, a trailer can make life easier. While it's possible to use panniers, handlebar bags and rear racks to carry loads on your frame, it affects the handling and performance of your bike and makes riding more dangerous. You can carry heavier loads on a trailer without these concerns and when you stop for the night you can leave the trailer behind to go riding with your friends. Since commercial trailers can be expensive, you might want to think about building your own.


Difficulty: Moderate

Flatbed Trailer Construction

Things You’ll Need:
  • Tape measure
  • Pencil
  • Small carpenters square
  • 1 miter, table, circular or hand saw
  • 4-foot sections of 1- by -2-inch lumber, 4
  • 3-foot-sections of 1- by 2-inch lumber, 2
  • 2-foot-sections of 1- by 2-inch lumber, 3
  • 4-inch-sections of 1- by 2-inch lumber, 4
  • 3- by 4-foot section of 1/4 inch plywood
  • Wood glue
  • 90-degree brackets, 8
  • 1 corded or cordless drill/screw gun
  • 1-inch flat-head wood screws
  • 2.5 inch drywall screws
  • 5 electrical box cover plates
  • 16-inch wheels, 2
  • 16 inch metal tubing
  • Hacksaw
  • Vise
  • Hammer
  • Pliers
  • Nuts and bolts
  • Adjustable wrench
  • 13 eye screws
  • 6 bungee cords
  • 1 U-clamp
Step 1
Lay out and cut the trailer frame. Use your tape measure, square and pencil to lay out the pieces for your frame and cut them to the specified sizes with your hand or electric saw. Make pencil lines 6 inches in from the ends of your 3-foot pieces. Make additional pencil lines at 1- foot intervals along two of your 4-foot pieces. Now make four more pencil lines 14 inches in from the ends of all four 4-foot pieces.
Step 2
Assemble the trailer frame. Apply wood glue to the ends of your 4-foot pieces and join them to the two 3-foot pieces to make a rectangle. Two of the 4-foot pieces will be lined up with the lines you drew 6 inches in from the ends of your 3-foot pieces. Use your 1-inch screws and screw gun to attach four 90-degree brackets to the inside corners where the outer 4-foot pieces meet the 3-foot pieces. Use more 1-inch screws to attach the remaining four 90-degree brackets to the outside corners where the inner 4-foot pieces meet the 3- foot pieces (at your 6-inch marks). Apply glue to the ends of your three 2-foot pieces and line them up with the lines you drew at 1-foot intervals on the inner 4-foot sections. Use your screw gun to drive 2.5-inch drywall screws through your inner 4- foot pieces and into the ends of your 2- foot sections. Apply glue to the ends of your 4-inch pieces and align them with the lines you drew 14 inches in from the ends of your 4-foot sections. Use your screw gun to drive the 2.5-inch drywall screws through the 4-foot sections and into the ends of your 4-inch pieces.
Step 3
Make and install the wheel mounts. Draw a line across the center of the electrical box cover plates. Put them in a vise and bend them in half along this line with your hammer and pliers. The cover plates come with a hole in the center, so half of this hole will now be along one edge. Drill a hole directly below this half hole and make it slightly larger than the diameter of your wheel axles. Put this hole in the middle of your bent cover plates. Now use your hacksaw to cut a channel from the half holes to the holes you just drilled and make this channel the same diameter as the holes you drilled. Mark the middle of this channel on your cover plates and the middle of your frame on both sides. Line up the marks on your frame with the marks on the plates and drill holes through the plates and into your frame. Bolt the cover plates to the inside edges of the outer 4-foot sections and to the outer edges of the inner 4-foot sections. The plates should be mounted, so the half holes and channels are facing down. This will allow gravity to keep the wheel axles inside the channels.
Step 4
Cut and install the plywood deck. Layout and cut a 3- by 4- foot section of 1/4 inch plywood. Lay out and cut a notch that's 5 inches deep by 20 inches long at the center of both 4- foot sides of your 1/4-inch plywood. Apply glue to the top of the frame and lay the plywood deck on it, making sure its edges are flush with the frame; then screw it in place with your 1-inch screws.
Step 5
Mount the wheels and install the eye screws. Drop the trailer over the wheels, so the axles slide into the channels in your cover plates. Install two evenly spaced eye screws near the 3-foot ends of your trailer and four evenly spaced eye screws near the 4-foot sides of your trailer. Attach your bungee cords to the eye screws.
Step 6
Make and mount the trailer arm. Use your hacksaw to cut a 16-inch section of metal tubing and bend it in your vise until it reaches from one side of the front of your trailer to your rear wheel. Flatten both ends of the tubing in your vise and drill one hole in the bent end and two in the straight one. Bend the remaining cover plate in half and drill two holes in it. Bolt the upper hole to the rear wheel on your bike and attach an eye bolt to the lower one. Run a U-clamp through the eye bolt and bolt the clamp to the bent end of your 16-inch metal tubing. Bolt the opposite, straight end of your metal tubing to the side of your trailer to complete the build.

Article Written By Dan Eash

Dan Eash began writing professionally in 1989, with articles in LaHabra's "Daily Star Progress" and the "Fullerton College Magazine." Since then, he's created scripts for doctor and dentist offices and published manuals, help files and a training video. His freelance efforts also include a book. Eash has a Fullerton College Associate of Arts in music/recording production and a Nova Institute multimedia production certificate.

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