On my last Cobra trailer I found my tires were old, and the standard wheels were not very attractive either. I measured up the lug nut hole pattern and ordered a couple of new wheels with the same bolt pattern, but in a wider and larger diameter wheel size. I think I went from a 13 inch wheel to a 15 inch. Check for clearance with the fender first of course.

Then I ordered 2 new Michelin car tires. Got it all on eBay for about $300. Had a local tire shop mount and balance them. Kept one of the original as a spare.

It looked a lot better, and rode a lot better too. The larger outside diameter rides over bumps and holes smoother. The total load on the tires, weight of the trailer and glider, is well within the load limit of the tires. Sway was no issue. Driving down the highway at 70 MPH there was little worry about a trailer tire blowout.