I have a hollywood traveler frame bike rack that I put my tandem on. it sticks out about 6 inches with the rear tire; 8-12 inches with the front tire on. I don't take the tire off when I am transporting it within town. When I drove 90 minutes I did take off the front tire to make it easier to get down he road. Let me take a pic tomorrow when it is light outside so you can see what it looks like.
I originally purchased it 10 years ago to haul 3 mountain bikes but it works better for the tandem then the small cages of MTB.
https://hollywoodracks.com/collectio...nt=47046093382