When architect and engineer David Schwartz was watching an uphill section of the 2011 Tour de France, he noticed that the riders' bodies were bobbing up and down as they pedaled. If only their backs had something to push against, he figured, that vertical motion could be converted into increased leverage on the pedals. The result is his proof-of-concept Flying Rider prototype bike.

Superficially reminiscent of the Fliz bike, the Flying Rider started out as a standard 1988 Schwinn road bike. Its seat tube and top tube have been removed, however, to be replaced with an arrangement of steel tubing that arches up over the rider's back. In what is no doubt the bike's most bizarre feature, the rider is suspended in a harness that hangs down from those tubes.

When they go to hammer on the pedals in a sprint or a climb, their back meets a sort of "cage" that holds them down. According to Schwartz, this results in a pedaling efficiency gain of around 10 percent for a 170-lb (77-kg) rider.

Recumbent bicycles are claimed to offer a similar advantage, in that the rider can push off against the seatback while pedaling – it's sort of like the difference between trying to push a fridge across the floor while simply standing next to it in the open, or standing next to it while bracing your back against a wall.

There are also tethers that can be purchased for use on regular bicycles, that loop around the rider's lower back and attach to the top tube. The idea is that as with the Flying Rider, they will hold the rider down and concentrate their power on the pedals. Their effectiveness is definitely a matter of debate, however.

While his current prototype might look a little ... odd, Schwartz is working on a purpose-built carbon fiber version which he hopes to have ready for the Interbike trade show in September. He welcomes inquiries from manufacturers wishing to license the design.

And perhaps you're wondering, is it comfortable? "We've tried two mountaineering harnesses from REI and also one custom-made leather weight lifter's belt," he told us. "None of them are perfect, but all of them are better for me than a seat ... I'm thinking that an athletic body-wear designer should rethink a hang glider-type harness for this bike."

Source: Flying Rider