I'm considering moving our bicycles off the back of the tow (Chevy Equinox) and putting them on a dual hitch extention (Curt Mfg. 45792 or similar) between the coach and tow vehicle. To do this I will need to run an additional 18" hitch extention (Camping World 26514 or similar) out of the lower dual hitch extention, bike rack in the top, to insure my Blue Ox Alladin (7,500#) has enough room to fold into the storage position with the bikes in place. Blue Ox has a 10,000# 12" extention but I don't believe that gives me enough room between the bikes and tow bar to store it as it is designed. As I read the specs on these extensions they are both rated at 4,000#. According to GM my tow vehicle curb weight is 3,758# to 3,993#. We do carry some ancillary items in the vehicle as we travel that will most likely push it above 4,000#. Does anyone have any experience/suggestions on this type of set up?