Thule's Pivoting Tandem Carrier enables one person to load a tandem bike on the roof of their car. Thule designed the Tandem Carrier to be easy to mount to either square or round load bars so that you don't have to leave the bike carrier on your vehicle all the time. When you can't find someone to ride on the other seat of your tandem, just convert the Tandem Carrier into a conventional bike tray for solo rides.