Mountain unicycling

Mountain unicycling is an adventure sport that consists of traversing rough terrain on a unicycle. Mountain unicycling ('muni') is undertaken on similar terrain to mountain biking. However, muni requires much more attention to the microfeatures of the short distance in front of the wheel. Unicycles' lack of a freewheel means that descents must be controlled all the way, and the typical lack a gear system (though two-gear hubs are available), prevents the rider from reaching high speeds. Muni usually takes place on specially designed unicycles, which are equipped with strong hubs, large, knobbly tires, high-grip pedals and rugged frames. Some are also equipped with rim or disc brakes, having the lever mounted under the nose of the saddle. The brake primarily helps to compensate the downhill-slope force, while more expert riders also use it to decelerate or stop.

Muni riders also need a few additional skills than required for either mountain biking or regular unicycling, with core strength and balance being key.

Relaxed mountain unicycling

Mountain unicycles (Surly)

...
Wikipedia