Your trike sounds like fun Dune Pro. I used to run 8" diameter rear wheels on my 250R, but I kept having issues with my paddles getting out of sync with one another. Basically, the rear wheels were slipping, or spinning, inside the tires, causing the paddles to get out of sync. Once they're out of sync, the bike tends to pull to one side or another, depending on which side hooks up first. Then, it was suggested that I switch to a 10" diameter rear wheel because the larger diameter gives more surface area for the tire to grip the wheel, thus preventing slippage. Once I did that, no more issues.