The goal is to make the wheel’s hub essentially float in mid-air while suspending the chair’s mass. Practically this means riders can traverse stairs and curbs nearly as easily as gliding down a ramp by allowing the wheels to bear the brunt of the forces. “Once you’ve eliminated sagging and bobbing you can work miracles,” says Barel.

Source: http://www.wired.com/2014/05/an-amazing-...