what kind of bike carrier do you like?

[dhk2]

MMM, your home-grown approach would make even a rocket-city redneck proud. But if I understand your design correctly, I'm not sure that it will be structurally safe just because you ask your local machine shop for heavy-gauge 2" tubing. If the rack ends up weighing 250 lbs w/o bikes, and you add 8 bikes @ 25 lbs each, you're at 450 lbs. At that point, the bending moment on the hitch will vastly exceed the design limits of "500 lbs", since that was based on trailer tongue weight. The hitch and mounting isn't rated for bending loads beyond what a normal trailer would present.

Under that kind of bending load, which the hitch designers never considered, the hitch itself may hold up, but the mounting points on the vehicle may yield. My guess is that you'll get adequate warning in event the mount yields to the bending loads while on a trip, but I'm not sure about that either. Suggest you might want to consult an engineer who's knowledgeable of vehicle design before proceeding. If not, just build it your way, but at least do a good overload test before taking it out on the road loaded with bikes, and then keep checking the hitch and mounting.

Overall, a light-weight trailer is a much better solution IMO.

 

[sitzmark]

Hate to say it M3, but you are getting close to skiing the trees as they say. Static weight probably would be OK, but the "lever action" when crossing dips in the road is going to turn your 6'-8' beam into a springboard when loaded. Probably time to pull out an equation or two and do some math. I chide engineers, but they do have their place.

Ground clearance has already been mentioned when navigating any kind of sharp incline. Add to that turning issues. Unlike a trailer, your beam won't articulate at the hitch, so if you turn sharply with anything next to your vehicle - like a sharp right turn at an intersection - there is a good chance that beam behind you is going to make a nice sweeping arc right across whatever is next to you. Something to think about and work into your design specs. Vertical may be better than horizontal (for the support structure). :wink:

Sounds like a fun challenge to work out the details. Good luck!