If you are a fabricator, know/ or can afford one, you could build the one I mentioned in the Earth Roamer Expedition Forum.
Don't know how to link it so I cut and pasted it so you can read it.
Here's the link to the Red Ant Patent. Go to download to see the drawings and my earlier description will make more sense. CYCLE CARRIER - RED ANT PRODUCTS INC,US
The specification discloses a carrier for carrying a motorcycle or the like on a motor vehicle and comprises two support arms adapted to be coupled to a motor vehicle for supporting a channel or rail
The Patents have been Public Property for years now.
GO to the PDF and download it to see it up close. It has everything but the dimensions! Which you can figure out easy enough to fit your needs.
I built these in the Factory back in the early 70's (I was in my early 20's) and being a mechanical mind I figured out how and what made them work. Then years later (3 years ago) I decided I needed one for myself and upscaled the design to make it carry my heavier bike (a Yamaha 1200 Tenere) and be more secure on the back of my Class A motorcoach. Mine works really slick!
For easy removal for when I don't need it, I added two more recievers to the ends of my frame, so my MH now has 3 receivers, and I can even tow a trailer if I want, but depending on your rear suspension you may need to beef it up for the added tounge wight.
The best part of it is it needs no ramps and can be made to carry almost any bike if you beef up the design to suit your needs.
I hauled my TW and then my WRX plus bikes with a Versahauler motorcycle carrier. They have a two inch hitch built into the carrier and you can plug in any bike rack that suits your fancy. If you only need one bike you can mount one of the front fork style mounts on the tiedown outrigger and rig up a rear wheel tray that plugs into the hitch. That is how I carried my tandem and it kept it tucked in really tight to the motorcycle. I can't seem to find a picture with the bike mounted but this might give yo an idea.
Welcome to Joe Hauler. We manufacture high quality hitch-mounted motorcycle carriers and custom motorcycle accessories that are easy to use and built to last. Innovation and quality craftsmanship are what set Joe Hauler apart from the competition. Now Offering a 3 Year Warranty on Joe Haulers.