I have two ADV motorcycles. I need to put them in a UHaul and trailer them across the country. After some Google searches, YouTube videos, and forum posts, I figured out the best way to make this happen. Here is a write up. I post this in the hope that it will help someone else in the future. Photos are at the bottom. I am writing this after having built the platform, but before I make my trip. I will try to update with photos once everything is strapped into the trailer. (Note: no affiliate links or anything -- I'm just writing this to help, not make money.)

Parts List: (quantity) Item

• (2) 1800lb Motorcycle wheel chocks from Harbor Freight
• (3) 4ft x 8ft x 3/4 in plywood

NOTE: 2 boards should be 4ft x 5ft 11in (gives you half an inch wiggle room to fit in the trailer). 1 board should be 3ft 6in x 5ft 11in (the interior is, I believe, 11ft 7in total)

• (1) 2 in x 4 in x 10ft
• (4) 1 3/4" or 2" hex head bolt and washer
• (16) Wood screws. Long enough to go through the 2x4 and most of the plywood. So approximately 2 1/2 in.
• (4) Eyelet bolts, 3" (plus washers)
• (8) Hitch Pin Clips -- this is not necessary, but I used these to replace the stock hitch pins that are used on the wheel chocks. I wanted something more substantive.

Problems:

Most people who trailer two motorcycles are trailering smaller bikes, or one big bike and one small bike. I have two big adventure bikes, so I needed to figure out a way to make them fit on one trailer. UHaul only rents a few trailers for one way travel. The 6x12 was the only one that would be able to fit my bikes, since the width of each bike is about 36" (2 x 36" = 72" = 6ft). I can't drill into the floor of the trailer, and the existing anchor points are insufficient (only a few D-Rings on the floor, from what I understand).

Additional Context:

I found this Reddit comment particularly useful, and it served as my inspiration.

Solution:

I built a custom platform that will fit within the trailer, that I can mount the bikes to. The bikes are staggered, in order to allow them to be closer together -- meaning that the bikes don't sit handlebar to handlebar. The handlebars on the second bike are approximately even with the gas tank on the first bike.

I bought two wheel chocks from Harbor Freight and mounted them to 3/4" plywood board. The stock feet that sit underneath the eyelet anchors on the wheel chock can be unscrewed. I replaced them with a comparable hex head bolt and washer. That way I could securely bolt the wheel chock to the plywood board. The washer helps distribute the tension.

Next, I mounted a couple of 2"x4" on either side of the rear wheel. The 2x4 is mounted to the plywood with 4 wood screws -- one screw in each corner. Each 2x4 has an eyelet bolt in the center. The eyelet bolt goes through the 2x4 and the plywood. There is a washer and nut on the underside that holds the eyelet bolt in place. The eyelet bolts serve as anchors for a ratchet strap, which will secure the rear of the bike. There is one of these eyelet anchors on each side of the rear wheel. A piece of advice -- you will want a stack of washer to put between the top side of the anchor bolt and the 2x4. That way when you tighten the bolt underneath, the bolt doesn't just press down into the wood.

You will want to measure the dimensions on your bike to make sure you have sufficient space. In my case, I mounted the front wheel chock 2 inches from the front of the board, to leave myself a little space just in case the trailer isn't a perfect 6x12. Both wheel chocks are mounted 3" from the edge of the board -- again, to have a little space and not have the bikes pushed up against the wall.