OK Fastmetal, now I am on board. I didn't see your post when I looked at the picture.
There is a 1340 cc Harley on the back of the MH. The rack probably weighs 200 lbs. and the Harley weighs 850. No one could tell me, how it would handle or even if it was possible.
Our motorhome weighs 21,800 and is rated to carry 26,000 lbs. We weighed it one time loading on a ship in Mexico and we weighed 24,889 without the Harley. We have been using this arrangement since 98 and have put 67,000 miles on the rig with no suspension problems. It's a Spartan Chassis with Air Suspension.
I wouldn't recommend putting this kind of rear weight on the back of a gas chassis, without doing some calculations. I have seen a Honda Gold wing on the back of a 34 foot gas rig in El Paso, with the same arrangement, but have no history of how well it lasted or how it handled.
If you calculate the rear axle rating and the weight of your bike and the rack combined, and you are not going to carry much else, if you are within the limits I would say you probably would be ok, but it's always a crap shoot.
There are some better pictures of the Harley rack on earlier posts. Maybe you can look back and get some ideas.
I found one of the old pictures.