For the design I'm considering this spring & hinge swiveling fork trailing wheel
would support the rigid mount trailer which would likely only extend 54 inches past the rear wheel.



Thus the rear wheel of the trailer would "dolly" like the front wheels of a grocery shopping cart and flex from the hinge mounting. A couple coil springs or bungee could dampen the movement of the wheel while under way. To stiffen the wagon perhaps a cross bar mounted on the upper rear frame with radius arms extending to the top front corners of the wagon box (shown in red) could stiffen it enough to ensure reliability. I don't forsee the trailer carrying a great deal of weight and I would likely carry a plastic weather resistant kids foot locker measuring 36" x 24" x 16" length, width, and depth. From the front axle of the bike to the aft end of the rear tire it's about 54" and the measurment from the aft end of the rear wheel to the aft end of the trailers rear wheel would be about the same 54". (by my calculations) The handlebars of my bike are 28" wide alone. I'm leaving 2 inches of space between the front of the trailer and the back of the rear tire.



In the view at the back end of the trailer you can see the tabs for the
rear suspension to fit into to and accept the rod to establish the hinge. Below it the springs would mount to the trailer and suspension. Since the forks are mounted in bearings and their angle to the ground is such that the rear wheel will turn with the trailers lateral movement the design should be functional.

The red line which extends along the bottom of the bike frame on back into the trailer bed shows the rods that mount rigid to the bicycle frame like the tongue of a trailer. With the upper radius supports (shown in red) I believe it could be viable for going on a road trip. Because the trailer isn't much wider than the bike and rider it would be easy to abide by Ohio's 3 ft from the edge of the highway rule (the zone of operation for motorized bikes) and also conform to the limit of 3 wheels and one rider.

I'm also considering leveling stands on the front corners of the trailer like pop up tent campers use for setting up and that would hold the bike & trailer level when parked. That would add to the usibility of the trailer. I figure the overall length of the bike with trailer would be similar to the length of a bicycle for two.

If I had to travel somewhere I think this trailer system would be more practicle than using a side car. At least that's my thoughts to this writing.