I dirt biked with several friends, but didn't like it much with a RV. Think about where you are going to put all of the dirt from serious riding inside a relatively small space. For riding in particular, you'd be much better off with a relatively low cost trailer type toy hauler for 10K or so. It basically has the same functionality as a truck cmaper in a better way to deal with the weight and also the dirt. Also, it is much, much, much cheaper than a top of the line TC with dual slides.
I agree that two bikes on hitch hauler, although possible, is not really viable with a normal hitch type. They do make some that have multiple supports capable of hauling Harleys, so it is technically possible. A trailer would be much easier.
As you can see from my signature, I have a 9.5 Host Double Slide. The models with more than one large sitting areas are even heavier than mine. My truck had no issue carrying my camper stock, but adding several hundred lbs behind the rear wheels won't exactly be fun to drive.
In summary, consider a lighter camper for 1/2 people if you really want a TC and pull a trailer as your overflow. Either a smaller toy hauler or enclosed trailer should work for a bike trailer and provide some sitting area.
'10 Ford F-450, 6.4, 4.30, 4x4, 14,500 GVWR, '06 Host Rainer 950 DS, Torklift Talon tiedowns, Glow Steps, and Fastguns. Bilstein 4600s, Firestone Bags, Toyo M655 Gs, Curt front hitch, Energy Suspension bump stops.
NRA Life Member, CCA Life Member