Quote Originally Posted by tprevost View Post
, DaVinci makes a tandem where you can each pedal at your own cadence.
On a Da Vinci you can coast whilst the other pedals, but when pedaling you maintain the same cadence, when the stoker begins to pedal, they time it so the pedals are in the proper position on the pedal strokes.

The biggest advantage to this that I could see is butt-rests at will, less need to get it together when starting off and lack of knee jerks when the captain forgets to mention a sudden stop or begin in pedaling.