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Unicycle Trials
Unicycle trials is a form of unicycling which involves participants attempting to ride a unicycle over obstacles without any part of the rider touching the ground. The obstacles traversed can be set up specifically for the purpose of unicycle trials, but are often walls, railings, ledges and other "street furniture" found in an urban environment. The sport is derived from (or at least inspired by) Bike trials riding, bike trials and Motorcycle trial, motorcycle trials. Obstacles are traversed using various moves. Hopping is achieved by suddenly forcing the unicycle pedals downwards while holding the seat, the reactive forces resulting from the compression of the tyre lift the unicycle into the air. Jumping is a similar to hopping, except that the unicycle seat is held in front of the rider to allow greater height to be achieved. Pedal grabs and crank grabs involve a hop or jump to land the unicycles Bicycle pedal, pedal or crank (mechanism), crank on the edge of an object, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumference
In geometry, the circumference () is the perimeter of a circle or ellipse. The circumference is the arc length of the circle, as if it were opened up and straightened out to a line segment. More generally, the perimeter is the curve length around any closed figure. Circumference may also refer to the circle itself, that is, the Locus (geometry), locus corresponding to the Edge (geometry), edge of a Disk (geometry), disk. The is the circumference, or length, of any one of its great circles. Circle The circumference of a circle is the distance around it, but if, as in many elementary treatments, distance is defined in terms of straight lines, this cannot be used as a definition. Under these circumstances, the circumference of a circle may be defined as the Limit (mathematics), limit of the perimeters of inscribed regular polygons as the number of sides increases without bound. The term circumference is used when measuring physical objects, as well as when considering abstrac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bike Trials
Mountain bike trials, also known as observed trials, is a discipline of mountain biking in which the rider attempts to pass through an obstacle course without setting foot to ground. Derived from motorcycle trials, it originated in Catalonia, Spain as (from , "motorcycle trials without an engine") and is said to have been invented by Pere Pi, the father of Ot Pi, a world champion motorcycle trials rider. Pi's father had wanted his son to learn motorcycle trials by practicing on an ordinary bicycle. Trials riding is an extreme test of bicycle handling skills, over many of obstacles, both natural and man-made. It now has a strong – though small – following worldwide, though it is still primarily a European sport. Skills taken from trials riding can be used practically on any bicycle for balance, for example controlled braking and track standing, or balancing on the bike without putting a foot down. Competition trial bikes are characterized by powerful brakes, wide handleb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 practiced professionally in circuses, by street performers, 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 mountain unicycling, an activity similar to mountain biking or trials. History 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 Penny Farthing and later the advent of the first unicycle into many variations including: the seatless unicycle (" ultimate wheel") the tall ("giraffe") unicycle and "2-wheelers" or "3-wheelers" (multiple wheels stacked directly on top of each other). During the late 1980s some extreme spo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountain Unicycling
Mountain unicycling is an adventure sport that consists of traversing rough terrain on a unicycle. Mountain unicycling (muni or municycling) 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.The Essential Guide to Mountain and Trials Unicycling, Kris Holm, p128, Unicycles' lack of a freewheel means that descents must be controlled all the way, and the typical lack of 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 ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square Taper
The bottom bracket on a bicycle connects the crankset (chainset) to the bicycle and allows the crankset to rotate freely. It contains a spindle to which the crankset attaches, and the bearings that allow the spindle and crankset to rotate. The chainrings and pedals attach to the cranks. Bottom bracket bearings fit inside the bottom bracket shell, which connects the seat tube, down tube and chain stays as part of the bicycle frame. The term "bracket" refers to the tube fittings that are used to hold frame tubes together in lugged steel frames which also form the shell that contains the spindle and bearings; the term is now used for all frames, bracketed or not. There is some disagreement as to whether the word ''axle'' or ''spindle'' should be used in particular contexts. The distinction is based on whether the unit is stationary, as in a hub, or rotates, as in a bottom bracket. American bicycle mechanic and author Sheldon Brown uses ''axle'' once and ''spindle'' four times i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Wheel Hub
A bicycle, also called a pedal cycle, bike, push-bike or cycle, is a human-powered or motor-assisted, pedal-driven, single-track vehicle, with two wheels attached to a frame, one behind the other. A is called a cyclist, or bicyclist. Bicycles were introduced in the 19th century in Europe. By the early 21st century there were more than 1 billion bicycles. There are many more bicycles than cars. Bicycles are the principal means of transport in many regions. They also provide a popular form of recreation, and have been adapted for use as children's toys. Bicycles are used for fitness, military and police applications, courier services, bicycle racing, and artistic cycling. The basic shape and configuration of a typical upright or "safety" bicycle, has changed little since the first chain-driven model was developed around 1885. However, many details have been improved, especially since the advent of modern materials and computer-aided design. These have allowed for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spline (mechanical)
A spline is a ridge or tooth on a drive shaft that matches with a groove in a mating piece and transfers torque to it, maintaining the angular correspondence between them. For instance, a gear mounted on a shaft might use a male spline on the shaft that matches the female spline on the gear. Adjacent images in the section below show a transmission input shaft with male splines and a clutch plate with mating female splines in the center hub, where the smooth tip of the axle would be supported in a pilot bearing in the flywheel (not pictured). An alternative to splines is a keyway and key, though splines provide a longer fatigue life, and can carry significantly greater torques for the size. Types There are several types of splines: ;Parallel key spline: where the sides of the equally spaced grooves are parallel in both directions, radial and axial. ;Involute spline: where the sides of the equally spaced grooves are involute, as with an involute gear, but not as tall. The c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the centre of the circle and whose endpoints lie on the circle. It can also be defined as the longest Chord (geometry), chord of the circle. Both definitions are also valid for the diameter of a sphere. In more modern usage, the length d of a diameter is also called the diameter. In this sense one speaks of diameter rather than diameter (which refers to the line segment itself), because all diameters of a circle or sphere have the same length, this being twice the radius r. :d = 2r \qquad\text\qquad r = \frac. The word "diameter" is derived from (), "diameter of a circle", from (), "across, through" and (), "measure". It is often abbreviated \text, \text, d, or \varnothing. Constructions With straightedge and compass, a diameter of a given circle can be constructed as the perpendicular bisector of an arbitrary chord. Drawing two diameters in this way can be used to locate the center of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unicycle Trials
Unicycle trials is a form of unicycling which involves participants attempting to ride a unicycle over obstacles without any part of the rider touching the ground. The obstacles traversed can be set up specifically for the purpose of unicycle trials, but are often walls, railings, ledges and other "street furniture" found in an urban environment. The sport is derived from (or at least inspired by) Bike trials riding, bike trials and Motorcycle trial, motorcycle trials. Obstacles are traversed using various moves. Hopping is achieved by suddenly forcing the unicycle pedals downwards while holding the seat, the reactive forces resulting from the compression of the tyre lift the unicycle into the air. Jumping is a similar to hopping, except that the unicycle seat is held in front of the rider to allow greater height to be achieved. Pedal grabs and crank grabs involve a hop or jump to land the unicycles Bicycle pedal, pedal or crank (mechanism), crank on the edge of an object, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crankset
The crankset (in the US) or chainset (in the UK) is the component of a bicycle drivetrain that converts the reciprocating motion of the rider's legs into rotational motion used to drive the chain or belt, which in turn drives the rear wheel. It consists of one or more sprockets, also called ''chainrings'' or ''chainwheels'' attached to the '' cranks'', ''arms'', or ''crankarms'' to which the pedals attach. It is connected to the rider by the pedals, to the bicycle frame by the bottom bracket, and to the rear sprocket, cassette or freewheel via the chain. Parts Cranks The two ''cranks'', one on each side and usually mounted 180° apart, connect the bottom bracket axle to the pedals. Lengths Bicycle cranks can vary in length to accommodate different sized riders and different types of cycling. Crank length is measured from the center of the pedal spindle to the center of the bottom bracket spindle or axle. The larger bicycle component manufacturers typically offe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
