In its prototype phase, NuBike hasn't reinvented the wheel, but possibly has improved upon the classic chain-drive design of bikes. The NuBike works with gravity. Its pedaling motion, which uses levers, is up-down, rather than round-and-round. It's said to be more efficient, more powerful, and gentler on the hips, knees and ankles. It folds up compactly, easily fitting into a car trunk. With its super sleek design, the NuBike is in the midst of its Kickstarter Campaign.