World Superbike Racer
Join Date: Feb 2017
Location: Albany NY
I Ride: 2016 gsxr 750, 2007 zx6r
Coming from PWC racing, I can say that I've considering using my old single trailer as a bike trailer. The issues you run into there in most cases is the height of the trailer. They're usually up there pretty good. I've seen retrofits with decks though but IMO, for the issues you're gonna find on a 200 dollar jetski trailer that you then have to modify you're better off spending a bit more and getting a harbor freight trailer that will already do what you want. They're also not very compact.
The car dolly idea is interesting though, those require almost no storage space.