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. Unicycling is practiced professionally in circuses, by street performers, and in festivals and as a hobby. Unicycles have also been used to create new sports such as unicycle hockey. In recent years unicycles have also been used in activities similar to mountain biking or trials.

US patents for single-wheeled 'velocipedes' were published in 1869 by Frederick Myers and in 1881 by Battista Scuri.

Unicycle design has developed since the advent of the first unicycle into many variations including: the seatless unicycle ("ultimate wheel") and the tall ("giraffe") unicycle. During the late 1980s some extreme sportsmen took an interest in the unicycle and modified unicycles to enable them to engage in off-road or mountain unicycling, trials unicycling and street unicycling.

Bicycles, tricycles and quadracycles share (with minor variations) several basic parts including wheels, pedals, cranks, forks, and the saddle with unicycles. Without a rider unicycles lack stability - however a proficient unicyclist is usually more stable than a similarly proficient rider on a bicycle as the wheel is not constrained by the linear axis of a frame. Unicycles usually lack brakes, gears, and the ability to freewheel.

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