This thing is a piece of engineering history, and the maker has put it up for sale on Ebay. This monocycle was built by hand, and much in the same way they would have made it back in 1873.
The Spaniard who made it used the 19th century documentation and the same handcrafting techniques to make the whole thing, the best part, it actually works.
It stands a respectable 6.16 feet tall, that is also the diameter of the singular wheel. The inner part has 238 teeth. The entire thing is combined of different types of steel alloy, all come together to not only make a monocycle that works, but looks good too. The starting bid is 13 grand, but for something so amazing, I would have expected a higher price.
An Engineering Marvel – 1873 Monocycle Replica on EBay [via bornrich]