OCDbikr - Rob,
I'll share with you an explanation to consider. Much has already been said.
This subject comes up fairly frequently. There are several things you need to verify. You will need to know what your current "ready to go" weight is on the rear axle compared to the GAWR. Next check the capacity of the receiver hitch - usually 350 or 500 lbs. Now get a good estimate of the motorcycle you wish to haul. Get an estimate of the carrier for the motorcycle. Now measure the distance from the front axle to the rear axle (the wheelbase). Need to know the distance from the rear axle to the center of your motorcycle carrier.
Ready to calculate the see-saw effect of any weight you place at some distance behind the rear axle. Multiply the weight of the motorcycle plus the carrier by the distance behind the rear axle. Divide this answer by the distance between the axles (wheelbase). This is the amount you are lifting off the front axle of your motorhome (the see-saw effect). If for example:
1. the motorcycle weighs 525 lbs
2. the carrier weighs 75 lbs
3. the motorcycle is being carried 9 feet behind the rear axle
4. wheelbase is 17 feet.
(525+75=600 x 9 feet = 5,400 divide by 17 = 317). In this example the motorcycle would be adding 917 lbs (600 lbs plus 317 lbs) to the rear axle and the front axle would be 317 lbs lighter.
This is going to be tough to make work. Most Class C motorhomes have extended frame pieces behind the rear axle to support a longer living area. The above example is based on some very rough guesstimates.
I was going to do a similar conversion using a 230 lb scooter. Decided instead to buy an enclosed fiberglass trailer similar to this
IronHorse. Provides "out of site, out of mind" storage for a motorcycle.