Columbus, Ohio Doo Dah Parade-2011 07 04 IMG 0161

A monowheel, or uniwheel, is a one-wheeled

single-track vehicle A single-track vehicle is a vehicle that leaves a single ground track as it moves forward. Single-track vehicles usually have little or no lateral stability when stationary but develop it when moving forward or controlled. In the case of wheeled v ...

similar to a

unicycle A unicycle is a vehicle that touches the ground with only one wheel. The most common variation has a frame with a saddle, and has a pedal-driven direct-drive. A two speed hub is commercially available for faster unicycling. Unicycling is practi ...

. Hand-cranked and pedal-powered monowheels were patented and built in the late 19th century; most built in the 20th and 21st century have been motorized. Some modern builders refer to these vehicles as monocycles, though that term is also sometimes used to describe motorized unicycles. The world speed record for a motorized monowheel is 98.464 km/h (61.18 mph).

Stability

Similar to bicycles, monowheels are stable in the direction of travel, but have limited horizontal stability. This is in contrast to unicycles which are unstable in both directions. Monowheels have also been found to have a lower speed required for stability when compared to unicycles. A monowheel remains upright due to gyroscopic effects, but its lack of stability makes it highly dependent on forward momentum and the balance of the rider, who must maintain stability while steering. Over the history of the monowheel, various stability enhancements have been tried such as support struts (Green & Dyer, 1869), skids and propellers (D'Harlingue Propeller-Driven Monowheel, 1914), as well as gyroscopes, fins, and rudders (The McLean V8 Monowheel, 2003). Many riders choose to control stability when at a stop by putting their feet on the ground, similar to bicycles and

motorcycles A motorcycle (motorbike, bike, or trike (if three-wheeled)) is a two or three-wheeled motor vehicle steered by a handlebar. Motorcycle design varies greatly to suit a range of different purposes: long-distance travel, commuting, cruisin ...

Variants and related vehicles

There have been many proposals for variants or uses, such as a horse-drawn monowheel or a monowheel

tank A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and good battlefield mobility provided by tracks and a powerful e ...

. An electric monowheel called

Dynasphere Dynasphere may refer to: * Dynasphere (vehicle), a monowheel vehicle designed by John Archibald Purves * Dynasphere (wind turbine), a vertical-axis wind turbine designed by Michael Reynolds See also * DYNAS DYNAS (from ''Dynamic Selectivity'') ...

was tested in 1932 in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

. In 1971, an American inventor named Kerry McLean built his first monocycle (aka monowheel). In 2000, he built a larger version, the McLean Rocket Roadster powered by a Buick V-8 engine, which subsequently crashed in 2001 during the initial test run. McLean survived and proceeded to build over 25 different variations of his version of the monocycle, from pedal powered models, 5HP models, all the way up to V8 powered models. In 2010, Nokia used two of McLean's monocycles in their commercials promoting the new Nokia SatNav smartphone. One variant called a RIOT wheel was presented at Burning Man in 2003. It involves the passengers sitting in front of the wheel and being balanced by a heavy counterweight inside the wheel. Rather than the typical ring drive, this vehicle is powered through a

sprocket A sprocket, sprocket-wheel or chainwheel is a profiled wheel with teeth that mesh with a chain, track or other perforated or indented material. The name 'sprocket' applies generally to any wheel upon which radial projections engage a chain pass ...

attached to the spokes. A company in the Netherlands began taking custom orders for a monocycle variant called the Wheelsurf in 2007. A related vehicle is the diwheel or the

dicycle A dicycle () (also known as a diwheel) is a vehicle with two parallel wheels, side by side, unlike single-track vehicles such as motorcycles and bicycles, which have two wheels inline. Originally used to refer to devices with large wheels and pe ...

, in which the rider is suspended between or inside of a pair of large wheels placed side by side. An example of this would be the character Axel from the Twisted Metal series of video games published by Sony.

References

External links

Video of Guinness world speed recordMonovelo, the 2008 Beijing Olympic Games Monowheel
*"Speedy New Motor-Hoop Amazes Italians", ''

Popular Science ''Popular Science'' (also known as ''PopSci'') is an American digital magazine carrying popular science content, which refers to articles for the general reader on science and technology subjects. ''Popular Science'' has won over 58 awards, incl ...

'', December 1924, page 40
scanned by Google Books
*"Amazing New Motor-Driven Hoop May Be Car of the Future", ''Popular Science'', May 1932, front cover and page 63
scanned by Google Books
*"War Tank on One Wheel, Operated by One Man", ''Popular Science'', November 1933, front cover and page 47
scanned by Google BooksCycle World: Circle CycleImpact Lab: History of the World’s Craziest Invention - The Monowheel
{{Human-powered vehicles Cycle types