Bi-Bici Tandem

An unusual machine made by Graziella in Italy.

We see a very clever transmission on this bike: the stoker's cranks are connected to a bottom bracket axle which runs through the middle of (but doesn't drive) the rear hub. The stoker's chain runs forward to the captain's chainset which acts as the transmission cross-over to a chain which runs back to a more or less conventional set of sprockets on the rear wheel.

But they say there is nothing new under the sun.....