Homemade hubs for RWD independent suspension.

[Rambozo]

Another option if you are concerned about seal wear, is to just use hub savers. They are a very thin hard stainless steel sleeve that presses on to the wear area. They are meant to repair hubs with deep seal grooves worn in them. Since you used standard trailer bearings, I'm sure you can find them. They also use the same type of system to repair harmonic balancers on engines with seal grooves worn in them. They are thin enough that you can use the same size seal, it will just have a little more tension on the slightly larger diameter shaft.

[SeanMurphy265]

I would leave the square tube frame rails and cut off everything above the frame rails. Build you a round tube cage and let her eat! There's a lot of race car frames built from mild steel; if you build it right it will be safe. I would look into some type of external reverse transmission, like the ones used on heavy trikes or Honda Gold Wing. It will be a pain in the but getting out to push it backwards. It has a cool factor fo-sho!