In the past few days, several readers have pointed me toward a recent Gizmodo post about a monocycle replica from 1873. The replica, which was handmade by a man in Spain, features a 6.16 foot diameter wheel. The workmanship is very impressive and the machine itself looks like it would be a lot of fun to ride. Be sure to check out the eBay auction for another picture. The auction has ended at this point with out anyone responding to the $13,000 opening bid. Yeah, that is a lot of money, but some modern production bikes cost half that amount and this is a one of a kind creation. You certainly wouldn’t have to worry about seeing another bike just like it on your local group ride
Just over 6 feet is a large wheel diameter, but it isn’t the largest that I have seen this week. David at the About.com Bicycling page posted about the Hyperbike (pictured here), which features two 8-foot wheels that are angled in at the top like a racing wheelchair. The machine’s designer, Curtis DeForest, was inspired in part by competition wheelchairs, which are very fast with a low center of gravity. One of the design goals was to make the machine as fast as a car on flat ground. The website explains:
“The circumference of an eight foot diameter wheel is roughly twenty-five feet and cadence, or the rate at which a person pedals, is most comfortable at a rate of 13 beats every 15 seconds. Gearing that allows an operator to rotate the wheels four times each pedal cycle, or at a 1:4 ratio while at the comfortable cadence rate will produce a speed upwards of 50mph.”
Certainly this design is very different from the majority of the bikes that you see on this site, but I think it is quite interesting. I encourage you to read the articles on the website, especially this one from the East Hampton Star. It sounds like this machine/trike would require a bit of practice to ride comfortably, but I would absolutely love to give it a try. Now that NASA is contributing some engineering expertise to the project, I am anxious to see Mr DeForest’s next prototype.