I hesitate to post this because this involves a lot more work than many/most might want to do, but it has worked out well for me so here it is. I bought a sheet of 3/4" plywood and cut it to fit inside the garage area from side to side, and made it about 38" from front to back. It is bolted down on all four corners of the plywood through the trailer floor AND through the top flange of the trailer's 12" I beam. It's not going anywhere, anytime soon.
I use Baxley brand Wheel chocks and they can be bolted down to prevent any movement whatsoever. So what I did there is to place the wheel chocks where I wanted them, mark the holes and drill into the 3/4" plywood and put a 5/16" machine thread insert into the plywood. I bought four, 5/16" machine screws that are the wingnut type instead of the traditional hex head bolts. So I place the chocks over the holes, screw in the machine bolts to hold them down and they are very secure from movement. If I don't need them in the trailer, I simply remove the bolts, set the wheel chocks out, and there is nothing sticking up from the plywood to stump you foot/toe on. Of course, as you can see, I also added some heavy duty tie down point exactly where I needed them before installing the plywood and bolting it down to the frame. It was a lot of work, as I stated earlier, but it was what I though might be a very good solution for my needs, and I already had the Baxley Wheel chocks......so I can remove them from the Toy Hauler and use them in my 6' x 10' flat bed utility trailer also if I just need to take the bikes somewhere without towing the Toy Hauler.
As far as tying down the bikes and using a Baxley, I run the bike into the Baxley and lock it in, then I use soft straps around the passenger peg mounting bracket and a ratchet strap on each side of the bike. The pull on the ratchet straps are DOWN AND FORWARD. I have probably well over 50,000 miles of hauling two bikes like this and have never had an issue. I don't need any additional strapping up front on the bike.....triple trees, handlebars, ect.......just the two straps on the back and pulling down and forward.
Here is a pic. of what I've got in the Toy Hauler....
Here is a pic of doing the same thing but using my 6' x 10' utility trailer.....
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