I have a Ram Promaster Cargo van with a class III hitch (500/5000 rated) and wanted to do the same. I spoke with a tech person at Curt Hitches yesterday and he said for me not to consider towing a VStrom 650 on a hitch hauler. He said that for every 14" the bike's track is behind the face of the receiver, the tongue weight is increased by 30%. So if you hitch hauler positions your bike at 14" out (most are almost double that), the static load on the hitch is equal to 650. Then when you go over a bump at 60 miles an hour that causes your suspension to compress rapidly and then stop rapidly, the SHOCK load could easily become 750 or 800 lbs. According to him, this is enough stress to compromise not only the hitch assembly; I is enough to deform a unibody frame. This stopped me dead in my tracks and sent me back to towing a trailer.
Note: If you are towing with a full size truck or SUV that has a steel frame underneath it AND you can get a Class IV hitch with a 1000 lb tongue weight rating then you should be able to do it but you may have to add load leveler air bags to help the vehicle drive properly.
In summary I came away from the conversation with the impression that hitch haulers are great for dirt bikes where the weight is kept to 300 lbs or less and even then you need to minimize the distance the bike is behind the face of the receiver.
Hope this helps.
