I purchased a 1720 lb. Capacity 4X8 Super Duty Trailer from Harbor Freight to build for carrying two motorcycles to various events. 1720 lb. Capacity 48 in. x 96 in. Super Duty Trailer
Follow along as I go over my build out of this trailer to meet my specific needs.
Front 4X4 section is assembled along with the tongue. The trailer is a basic bolt-together process and I utilized the flat surface of my garage floor with cardboard down to prevent it from being scratched. I also measured diagonally from corner to corner (making a 'X' pattern) on the front and rear sections to ensure each section was indeed square.
The gauge of steel is beefy enough to handle two motorcycles, a pit bike, tools, gear, gas cans, and ramps. I've had another trailer similar to this but the gauge was thinner and it could only handle 1 bike plus a few odds and ends.
Main chassis completely assembled (sorry about vertical photo). All bolts are to specifications, hubs were cleaned and fully greased, and it is now ready for the next stage. It is very, VERY important that you fully clean and grease the hubs for this trailer! They only put in enough grease to keep the bearings and races from rusting during storage at the store. If you do not do a full clean and lube then the bearings will end up failing very rapidly which could result in people getting seriously hurt or killed.
I opted to buy 3 pieces of 4' X 2.5" angle iron for strength and to give me a place to drill holes for attaching the decking. This allowed me to mount the boards and not worry about damaging any of the structural strength of the trailer. Here you can see them sand blasted, cleaned, and primed with self etching primer.
I am pleased with the welds and the added steel really stiffened the trailer. At this point I cleaned the slag some more, wire brushed the general area, cleaned it all with rubbing alcohol, and wiped clean with a fairly lint free cloth.
I applied more etching primer to the area, being sure to overlap the existing powder coat.
All joints have now been etch primed.
First top coat has been applied.
This stuff is crazy sticky....my arms feel like they are covered in honey.
Now I am spending some time wiring up the trailer.
The wires might appear tight but that is the camera angle.
To protect the wires I ran them through some wire loom. All wire connections are soldered and heat shrinked, even the grounding connector is crimped and soldered on.
I now have the side marker lights in the wire loom as well.
Attaching the boards to the trailer in this series of pics. They are secured to the angle iron I welded onto the trailer with carriage bolts, fender washers and lock nuts. I made a design choice to use 2X8s for the deck as I want to have a slightly wider surface for the motorcycles. This resulted in a lot of router work to make a channel and also recessed pockets for the top of the bolts around the edges of the trailer and last I had to notch around the fenders. This allowed the 2X8 to sit flush on the trailer making the surface level. I dropped a straight edge across the back and ripped all boards to equal lengths. I have read these HF trailers will lose fenders pretty easily so I decided to pre-drill for and use 4" lag bolt to attach the fender to the 2X8 decking.