I have a 42 year old Honda CT90 Trail bike I tote around with me. I wanted it on the front to keep the back doors clear so I found a pair of "bumper carriers" otherwise known as "loops" on Ebay. These are as old as the motorcycle and work just super on my RV. Newer units may not have the bumper necessary for these slip on carriers. Anyway, it works great for me. If I hadn't been able to find these I would have got a carrier that fits into the standard 2 inch receiver that I also have on the front. I'll try attaching a photo here for you to see of a pair for sale on Ebay right now. Good luck.
http://i.ebayimg.com/t/MOTOR-CYCLE-LOOP ... g~~_35.JPG