Neat trailer design. I'd add a second pin to the towing bar joint to keep the up and down forces on the moving trailer from working on the clearances in a single pin.fit. To tell the truth I think I'll use that joint idea for extending the tow bar length on the cheap Chinese import trailer I want to use for my semi cocktail racer I'm puting together. What's the "semi" thing about? Well, there is no cocktail racer activity where I live in the USA so I'm puting a real motor on it. (a Merc mark 25)I've done this sort of crazy thing before, too much motor on a little boat, so I know where the limits are. Beides the boat I have is a foot longer and heavier than the standard cocktail racer.