Hitch extensions: Reese makes a Titan hitch with 2.5" receiver for the slide-in truck camper crowd that takes along a boat, cargo trailer etc. I have such a 41" extension rated for 5,000 lbs in a weight-carrying use and 500 lbs tongue weight. These work as both an extension of the hitch and a reducer from 2.5" at the hitch to 2" at the other end so they accept normal hitch ball mounts, bike racks, etc. I've hauled my DR350 (310 lbs) on a heavy, overbuilt (and since revised/lightened) electric-lift bike carrier of my design (150 lbs) on this extension behind my Lance camper repeatedly and over some unimproved roads I probably shouldn't have. No problems to date. I realize this is not your application (no 2.5" hitches for van that I found) but I don't think you'll have any trouble hauling your bike on a reasonable extension so long as you use a sufficiently strong hitch and well made extension (Reese makes a nice 18" long 2" hitch extender rated for 4,000 lbs) and act responsibly with it. I check all my hitch pins and safety chains, tire temps, tie downs, etc etc etc a mile after departure (convenient pulloff near my house) and again at every fuel stop and only used my extension and bike lift after stress-testing them under safe conditions with a load much greater than I'll ever actually carry or tow on a public road. YMMV