Wallace, you did the correct thing. Call the source and get the correct information. You will find any question that concerns a rear hitch, the first comment will be about a voided warranty. Most of the heavier 5th wheel will have a option for a rear hitch. We ordered the heavy duty hitch, a 2" receiver with 3,000 lb towing capacity, and with a 15" frame there want be a problem. We will use our rear hitch for the bikes for sure if we decided not to double tow. GBY.....