Engineer and YouTuber The Q builds many novel and remarkably high-performing machines, most often with bicycles. Recently, we featured his bike tires made out of tennis balls. Those might work well in an off-road environment where punctures are likely.
So might these wheels, which are square. Or, more precisely, these are treads that rotate around a square frame. Inspired by the polyhedral tires in low-resolution video game graphics, he made this tread-bike that is surprisingly functional. I'm especially impressed with how The Q was able to transfer power from the bike pedals to the tread gears on the back wheel.
-via Laughing Squid