by meach4x4 » Tue Jun 22, 2010 11:07 am
Let me toss a few more considerations into the mix here:
- One of the builders here on the forum (schancy) built an off-road version of his lightweight Explorer Box trailer. To get a great ride and enough lift for a bit larger tires, he welded on shackle mounts to fit springs from a YJ Wrangler ('89-'95-) and removed leafs from the springs to get a good rate for the weight of his trailer (~1,000 lbs). He noted that the longer springs were way more supple, and 40 mph across washboard was no problem with no bouncing.
- Nice idea using the factory trailer for a base. They are a great start for a trailer. I let one slip through my fingers (sold it to buy my Wells Cargo V nose, and now I am looking at building another trailer, I am kicking myself for not hanging on to it.
- If you are going to tow on trails (which is how I translate "off road") I would recommend keeping lightweight constructon at the head of the list of goals. I didn't see what you are planning on using for a tow vehicle, but any off road tow rig will be limited by the amount of weight you are pulling behind it. Instead of using 2x4s, or 2x2s, and 3/4" ply, consider using 1x1 framing and Luan or 1/4" Birch. For walls, if you are using foam board insulation, you can glue the insulation between the paneling for a sandwich that will give a lot of strength without the weight.
- Consider adding brakes to the trailer. Even a lightweight trailer is going to try to push your towrig down a steep trail. With brakes on the trailer, you won't be fighting a trailer when you're going down a steep slick trail. Be sure to tune the brake controller for the load AND the trail traction. Another advantage of trailer brakes is on slick trail you can use the brake controller to manually apply a little brake on the trailer and straighten it out behind your tow vehicle.
- Build the trailer so the center of gravity is low, and build the load restraints to keep the center of gravity low after you load it. I have footman loops and cargo loops in the floor and low along the walls so everything is on the floor during transport. This makes a big difference in how the trailer reacts on off-camber trails and roads.
- Pay attention to being able to seal up the trailer during transport. If you have non-closeable vents and leaks around doors, driving over dusty roads will fill your trailer with dust. Make sure door frames are solid and tight when they are closed.
- I have 31x10.50x15 BFG All Terrain KO's on my cargo trailer, and they work great. A good tire is critical, since you will be working it harder on a rocky trail or washboard than most trailer tires. One of the places I like to camp has 70 miles of washboard road followed by 10 miles of rocky trail to get to the campsite. Normal trailer tires won't hold up. According to the park service, 1 out of 4 vehicles on that road have a flat. Carry a spare!
I hope some of this is helpful,
Gil