Clown Unicycle

The Clown Unicycle is a human-powered, single-track vehicle with one wheel. Unicycles resemble bicycles, but are less complex.

History

One theory of the advent of the unicycle stems from the popularity of the penny-farthing (or "Ordinary") during the late 19th century. Since the pedal and cranks were connected directly to the front axle, the rear wheel would go up in the air and the rider would be moved slightly forward. Many penny-farthing owners discovered they could dispense with the frame and just ride the front wheel and handlebars. Evidence for this theory of development can reportedly be found in pictures from the late 19th century showing unicycles with large wheels.

Over the years, unicycle enthusiasts have inspired manufacturers to create new designs, such as seatless ("ultimate wheel") and tall ("giraffe") unicycles. During the late 1980s some extreme sportsmen took an interest in the unicycle and started off-road unicycling ("MUni", or "mountain unicycling").

Construction

Unicycles have a few key parts:

• The wheel (which includes the tire, tube, rim, spokes, hub and axle)
• The cranks
• Pedals
• Fork-style frame
• Seatpost
• Saddle (the seat of the unicycle)

The wheel usually looks like a bicycle wheel with a special hub designed so the axle is a fixed part of the hub. This means the rotation of the cranks directly controls the rotation of the wheel (called direct drive). The frame sits on top of the axle bearings, while the cranks attach to the ends of the axle. The seatpost links the frame to the saddle.

Types of unicycle include

• Freestyle unicycles
• Trials unicycles
• MUnis
• Giraffes
• Long distance unicycles

Each type has special components unique to that type of unicycle.

Training aids

Having training aids may make it easier to become comfortable with riding a unicycle. One method for training is using a spotter to make riding easier. One other easy way to learn is to find a narrow hallway that can be used to help alleviate left and right balancing while allowing a beginner to focus on forward and backward balance. If a hallway cannot be found, a fence or clothes line is suitable. Equally, riding back and forth between two chairs, faced back to back, whilst holding on to the chair backs allows the user to gauge how to appropriately position oneself before setting off. Using props such as sticks or ski poles is generally discouraged as they hinder balance and create dependence. A fall onto props could also cause serious injury.

Types of unicycles

Freestyle unicycles

Generally used for flatland skills and freestyle routines. Usually have a relatively high seatpost, a narrow saddle, and a squared fork (used for one-footed tricks). These unicycles are used similarly to flatland bicycles. Wheel size is usually 20 inches (510 mm), but smaller riders may use 16-inch (410 mm) or 12-inch (300 mm) unicycles. Some people prefer 24-inch (610 mm) wheels.

Trials unicycles

Designed for unicycle trials, trials unicycles are stronger than standard unicycles in order to withstand the stresses caused by jumping, dropping, and supporting the weight of the unicycle and rider on components such as the pedals and cranks. Many trials unicycles also have wide, 19 or 20-inch (510 mm) knobby tires to absorb some of the impact on drops.

Mountain Unicycles ("MUnis")

"MUni" or "muni" is an abbreviation for mountain unicycling. MUnis have many of the same components as trials unicycles, but have a few key differences. Usually, the tire diameters on mountain unicycles are either 24 or 26 inches (660 mm), allowing the rider to more easily roll over obstacles such as roots and rocks. 29 inch munis are also used but are usually used for longer trips, or just a challenge. The seat is also thicker and more comfortable on MUnis to compensate for the rough terrain. Brakes are sometimes used for steep descents.

Touring unicycles

Used for long distances, these unicycles are specially made to cover distances. They have a large wheel diameter, between 26 and 36 in., so more distance is covered in less pedal rotation. A 36" unicycle made by the Coker Tire company started the big wheel trend. Some variations on the traditional touring unicycle include the Schlumpf "GUni" (geared unicycle), which uses a two-speed internal fixed-geared hub. Larger direct-drive wheels tend to have shorter cranks to allow for easier cadence and more speed. Geared wheels, with an effective diameter larger than the wheel itself, tend to use longer cranks to increase torque as they are not required to achieve such high cadences as direct-drive wheels, but demand greater force per pedal stroke.

Other variations

• Giraffe: a chain-driven unicycle. use of a chain can make the unicycle much taller than standard unicycles (note that multi-wheel unicycles can be described as giraffes). Standard unicycles don't have a chain, which limits the seat height based on how long the rider's legs are, because there the crank is attached directly to the wheel axle. Giraffe unicycles can range in heights from 3 feet to over 10 feet high.
• Geared unicycle ("GUni"): a unicycle whose wheel rotates faster than the pedal cadence. They are used for distance riding and racing.
• Multi-wheeled unicycle: a unicycle with more than one wheel, stacked on top of each other so that only one wheel touches the ground (nicknamed stacks). The wheels are linked together by chains or direct contact with each other.
• Kangaroo unicycle: a unicycle that has both the cranks facing in the same direction. They are so named due to the hopping motion of the rider's legs, supposedly resembling the jumping of a kangaroo.
• Eccentric unicycle: a unicycle that has the hub off-center in the wheel. Putting an eccentric wheel on a kangaroo unicycle can make riding easier, and the rider's motion appear more kangaroo-like.
• Ultimate wheel: a unicycle with no frame or seat, just a wheel and pedals.
• Impossible wheel (BC wheel): a wheel with pegs or metal plates connected to the axle for the rider to stand on. These wheels are for coasting and jumping. A purist form of unicycle, without cranks.
• Monocycle (or monowheel): a large wheel inside which the rider sits (as in a hamster wheel), either motorized or pedal-powered. The greater gyroscopic properties and lower center of mass make it easier to balance than a normal unicycle but less maneuverable.
• Self-balancing unicycle: a computer-controlled, motor-driven, self-balancing unicycle.
• Freewheeling unicycle: a unicycle in which the hub has a freewheel mechanism, allowing the rider, to coast or move forward without pedaling, as a common bicycle does. These unicycles almost always have brakes because they cannot stop the way traditional unicycles do. The brake lever is generally mounted in the bottom of the saddle. These unicycles also cannot go backwards.

Other variations include:

• tandem
• recumbent
• hydraulic giraffe
• unibike
• suicycle
• motorized unicycle

Theory

As with bicycles, unicycles lack stability when stationary, and under most circumstances can only remain upright when moving. Experimentation and mathematical analysis have shown that a unicycle stays upright when it is steered to keep its wheel beneath its center of mass (inverse pendulum control theory). This steering is supplied by a rider. Long-standing hypotheses and claims that gyroscopic effect is the main stabilizing force have been discredited. Unicycles are also a nonholonomic system because its outcome is path-dependent. The problem of controlling a self-balancing unicycle forms an interesting problem in control theory.

In order to ride the unicycle a proficient rider subconsciously notices they are falling and corrects it (bringing the wheel under their centre of gravity) before the unicycle moves far from its unstable equilibrium. While remaining upright may be the primary goal of beginning riders, they must (in order to voluntarily turn, accelerate or decelerate) allow themselves to 'fall' in the appropriate direction, before correcting it.

The horizontal distance between the centre of gravity and the contact point (between the wheel and the floor) determines the acceleration in a particular direction. The speed and direction of the wheel's rotation (pedalling) then determines the relative position of the contact point (and thus the increase/decrease in acceleration).

If a unicyclist is (far) off balance they can't move their centre of gravity to the other side of the wheel (the base of which is the fulcrum) without pushing off a wall (or similar)—so in order not to fall over, they must turn the wheel (with their lower body) and move it (by pedalling) underneath their centre of gravity.

Voluntary movement in a particular direction involves allowing a rider's centre of gravity to 'fall' in the direction they desire to move, generally this begins by subtle arm motions or leaning. Once more proficient, a rider may twist their hips (and counter rotate their body) in order to line up the wheel with the direction, they are going to fall toward, before they begin 'falling' in that direction, and thus they can immediately begin riding in that direction despite any sudden change in velocity.

Once a rider is in motion they shift their centre of gravity forward of the wheel's contact point to accelerate, shift it behind to decelerate, and keep their centre of gravity over the contact point to maintain a constant velocity. But significantly (and counter intuitively) the most significant way to affect the acceleration acting on the rider's centre of gravity is by adjusting their pedalling speed and direction, and thus the contact point, not by leaning their body.

Speed

The pedals of a typical unicycle (e.g. not a giraffe or guni) connect directly to the wheel. This means that there are no gears to shift and provides a very direct feel of the wheel contact with the ground. It also means that wheel size is a major factor in unicycle speeds. Detroit, Phoenix, Minneapolis, and Toronto. Switzerland, France, Germany and Puerto Rico are all field teams. The Puerto Rico All Stars has been one of the dominant teams and has won several world championships.

Unicycle hockey

Unicycle hockey follows rules basically similar to ice hockey or inline hockey, using a tennis ball and ice-hockey sticks. Play is mostly non-contact. The sport has active leagues in Germany, Switzerland and the UK and international tournaments held at least bi-annually. Tournaments in the UK are held by various teams across the country usually in sports halls, but occasionally outside. Each tournament lasts a day and around 8 teams normally compete in a round-robin league with the winner being whoever has the most points. If two teams have the same number of points the winner can be decided by goal difference or a penalty shoot-out.

Unicycle handball

Unicycle handball uses a handball-sized ball. The teams aim to throw it into a vertical hoop placed about 6 feet (1.8 m) above the ground It has been played in the Polish village of Chrzelice since late 1970s

Equipment and safety

Wrist guards

The most common impact points when falling from a unicycle are the feet (an unexpected dismount), but when falling out of control the hands and wrists are the next most common. Of all the safety gear, wrist guards receive the most wear and tear.

Knee and elbow pads

The second most common impact point is the knees, followed by the elbows. Knee pads are required for events like racing and MUni.

Helmet

A helmet becomes especially important when partaking in specialty riding such as MUni, and, in some jurisdictions, is required for road riding as well as racing, MUni, and other events. The helmet is helpful against hitting one's head on the ground, trees, and branches.

Shin guards

Shin guards become a necessary piece of equipment when using metal or pinned pedals. These types of pedals grip the shoes best, but can cause injury to the legs.

Cycling shorts

Padded cycling shorts are designed with a seamless, padded crotch, and long enough legs to extend down past the saddle, making them much more comfortable than "normal" shorts.

Gloves

Gloves are required at some unicycling events such as racing. Gloves may be fingerless (but fingerless gloves are not recommended). They are also very useful for protecting the hands in MUni and Trials riding.

UNICON and Eurocycle

UNICON and Eurocycle are regular international unicycling conventions.

The biennial UNICON (International Unicycling Convention), sanctioned by the International Unicycling Federation, comprises all major unicycling events and is the premiere event on the international unicycling calendar. Events include: artistic (group, pairs, individual, standard skill, open-X), track racing (100 metres, 400 metres, 800 metres, 30 metres walk the wheel, 50 metres one-foot), 10 kilometres, marathon (42.195 km), muni (cross-country, uphill, downhill, North Shore downhill), trials, basketball and hockey. Each team consisted of a maximum of 3 riders and 1 support person.

Unicross, or unicycle cyclocross is an emerging race format in which unicycles race over a cyclocross course.

Unicycle manufacturing companies

Notable unicycle manufacturing companies include:

• Coker
• Kris Holm Unicycles
• Miyata
• Surly
• Torker
• Nimbus