I pull an Aluma Motorcycle trailer behind my motorhome or F-150. It is 81" between the enclosed fenders with 2 moto rails full length. The trailer is 2 wheel, rock guard V front and is just over 12 feet. It is very light being only 700 lbs. It carries a 4' ramp underneath. Rubber torsion bar suspension and is rock steady loaded or not. It cost about 2700 dollars brand new out the door (2001). It is a production trailer and not special order.
My K1200LT with a Hannigan KLT sidecar goes up on it easily. Whether it is my rig or my solo K1100LT or the KLR I operate a winch to do the pulling. 3 HD relays and and feed wire + 45 feet of telephone wire to my handlbar control box makes loading a breeze.
I wrenched my back loading my K1200LT as a solo inside an enclosed trailer and felt that it wasn't worth the injury (wrestle) to get a big 2 wheel moto in and out of one. One has to decide if cycle cleanup after a "weather" trip is worth for an open trailer................... Campground parking is very easy even with out pull-thru since I can tow my outfit around by hand with a lite dolly.
This setup is light and handles beautifully. Not too expensive and has seen many trips across NA. & Alaska. My trips focus on fishing......................... so I frequently spend weeks at one spot and then move on. Well, until my wife reels me home....................
Trailer is 102" max outside to outside of each wheel/tire. This is the max width for USA and Canada with out an ad hoc permit.