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Trials Unicycling
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 and 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 pedal or crank on the edge of an object, and then a second hop or jump to land the unicycle fully on the object. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumference
In geometry, the circumference (from Latin ''circumferens'', meaning "carrying around") is the perimeter of a circle or ellipse. That is, the circumference would be 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 corresponding to the edge of a 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 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 abstract g ... [...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 ''trial sin motor'', "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 ... [...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 bicycle frame, frame with a bicycle saddle, saddle, and has a human-powered vehicle, pedal-driven direct-drive mechanism, direct-drive. A two speed hub is commercially available for faster unicycling. Unicycling is practiced professionally in circuses, by street performance, 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 Mountain bike trials, 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") and the tall ("giraffe") unicycle. During the late ... [...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) 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 additional skill ... [...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 in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Wheel Hub
A bicycle, also called a pedal cycle, bike or cycle, is a human-powered or motor-powered assisted, pedal-driven, single-track vehicle, having 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, more than 1 billion were in existence. These numbers far exceed the number of cars, both in total and ranked by the number of individual models produced. They are the principal means of transportation in many regions. They also provide a popular form of recreation, and have been adapted for use as children's toys, general fitness, military and police applications, courier services, bicycle racing, and bicycle stunts. 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 mode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spline (mechanical)
Splines are ridges or teeth on a drive shaft that matches with grooves in a mating piece and transfer 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. The splines on the pictured drive shaft match with the female splines in the center of the clutch plate, while the smooth tip of the axle is supported in the pilot bearing in the flywheel. 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 curves increase strength by decreasing stress concentrations. ;Crowned spl ... [...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 center of the circle and whose endpoints lie on the circle. It can also be defined as the longest 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. For a convex shape in the plane, the diameter is defined to be the largest distance that can be formed between two opposite parallel lines tangent to its boundary, and the is often defined to be the smallest such distance. Both quantities can be calculated efficiently using rotating calipers. For a curve of constant width such as the Reuleaux triangle, the width and diameter are the same because all ... [...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 and 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 pedal or crank on the edge of an object, and then a second hop or jump to land the unicycle fully on the object. A ... [...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 offer cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
