A bicycle is already pretty damn simple. Two wheels, a frame, a seat, pedals and a chain. What happens if you remove the chains though? That would give you the Bicymple—a bicycle that's even more simple than you could ever imagine.
Why would you make a bicycle without a chain? Well, aside from the answer of why not, the folks behind Bicymple explain:
By removing the chain, the number of moving parts and overall complexity is significantly reduced. A direct-drive, freewheeling hub joins the crank arm axis with the rear-wheel axis, shortening the wheelbase and minimizing the design.
More than just a stylish concept bike, the bicymple is comfortable, easy to ride, and brilliantly simple to maintain. The lightweight design and short wheelbase make for a nimble ride. The optional rear-steer mode is reminiscent of custom "swing bikes" and allows tighter turns and "crab-riding".