I have a hard time understanding how the floor in the toy hauler would be unable to support the load of a large motorcycle. I have an enclosed Trailers Plus Loadmaster 6 x 12 trailer and the floor is their factory standard 1/2 plywood on steel channels spaced 24 inches on center. I have hauled my Harley Ultra Classic several thousand miles and the floor at the rear wheels hasn't moved a bit. I have a HF chock (the Condor clone) and e-track on the sides of the trailer. I use rachet type straps with soft ties. I think placing separate plywood under the rear wheel to distribute the weight over more framing members might be a good idea and certainly couldn't hurt but shouldn't be required in a Toy Hauler "hopefully" designed to haul small vehicles. I will make sure the dealer verifies with the factory that my 347 THT will handle my Harley. Thats what we purchased it for afterall. Good luck.