Yeah, I was worried quite a bit as well, that is why I am having them fabricate the custom hitch with three receiver points. I would definitely rather over build than under build!
Motorcycles and bicycles are a HUGE part of my families life. My wife, kids, and I all ride, and both of my sons race motocross as well as BMX, so being able to "take it with us" is a huge concern for the family. My wife mainly takes her hopped up Zuma 125 scooter (212 lbs according to the scale at the COOP. We ridded off a few things and replaced the stock pipe with an aftermarket to put it on a diet to hit that number.) and I would LOVE to be able to rig it so I can take my F 800 GS, but I would settle with my 500 EXC if I had to (LOVE the cruising comfort of the bigger bike, but the all up weight with it wet to ride with a half tank of fuel is close to 440lbs!).
I figure with the triple class three mounting points grafted onto the kit rack (supposed to hold two bikes totaling 600lbs, plus two five gallon fuel jugs which I would leave off = 10 gal @ 6.2lbs / gal=62lbs) I should be in the limits according to the rack specs, and that is with it having just the single class III mounting point
I'm not expecting "triple the lifting capacity with triple the receivers", but I would think the two bikes as listed would be a doable proposition.
Ultimately it boils down to safety, and that is something I am definitely not going to compromise on. If I can't do it I can't do it, and we will take a trailer on our trips. The rear carrier though holds so much appeal to me as trailers are usually a PITA. Trips where we meet other family members and are at a location for a week or so it is REALLY nice to have the escape pod I can hop on and go out and do a little sight seeing while the rest of the family is playing at the beach or the kids are out hiking around, and it is always great to have something to shoot into town and pick up a few supplies with without having to completely break camp and go. I am sure there is a solution to this, I just want to bounce this off all of you that have "been there and done that".
Thanks again!