This is my bicycle cargo trailer I built from a child carrier bike trailer. I used quarter inch plywood and bolted it to the trailer frame using 3 inch carriage bolts. Metal brackets for the reflector brackets. Eye-bolts to strap cargo to the trailer, and some metal flashing for a “bumper” to keep the wood from getting marred. For the hitch I used a fence bracket meant for attaching a gate to a fence post. The bracket bolts to the bike frame (no holes in the frame). And I drilled a hole through the bracket to attach the trailer tongue using a 4 inch carriage bolt and wing nut to tighten it. The trailer comfortably carries 50 pounds, and has carried up to 180 pounds. It has full range of motion at the hitch and does not tip over. The cost for building it was about 20 dollars. The trailer itself weighs 30 pounds.