Bicycle Transport

We are doing more towing with our Expedition, and less with the F150. Wondering if anyone had any ideas for bike transport inside the RV. We do not have a reinforced bumper, and would be reluctant to do a bumper tow. I also don't want to put additional weight on the rear end by using a trailer frame mount over the propane tanks. And getting bikes to the roof of the Expedition seems as if it would be a daunting task. I have heard of some mods where bikes are secured to the dining benches. Wondering if anyone has had any success in that capacity and would be willing to share any information.