This monocycle replica from 1873 is an stunning engineering and mechanical feat. Created by a spaniard using 19th Century documentation and old-style handcrafting techniques, it uses a 6.16-foot wheel, with a 238-teeth inner segment, the quality of his work is simply amazing.
This man from Burgos, Spain, created the whole thing by himself, casting the main bronze wheel from a carved oak model. He also used different steel alloys for different parts of the mechanism, depending on the stress they are going to suffer. The saddle's suspension bar was treated in a forge to obtain the necessary elasticity to make it work right.The bidding starts at $13,000 and given the quality of the work, I would pay that and more (if I had the money, that is.)
Source: eBay via Boing Boing