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| And maybe at least one reference to a sports science article that explains how cycling is the most efficient form of human powered transport. | And maybe at least one reference to a sports science article that explains how cycling is the most efficient form of human powered transport. | ||
Revision as of 02:30, 27 February 2003
A bicycle is a small land vehicle with two tandem wheels (hence the name) powered by a seated human rider. Cycling or riding bicycles is one of the principal forms of transportation in several parts of the world. It is also a common recreation and popular sport.
Typical speeds for bicycles are 10-15 mph or 15-25 km/h. On a fast racing bicycle, a reasonably fit rider can ride at 30 mph or 50 km/h on the flat for short periods. The highest speed ever attained on the flat, without riding behind a wind-block, is by Canadian Sam Whittingham, who in 2001 set a 80.55 mph or 142.51 km/h record on his highly aerodynamic recumbent bicycle. This stands as the record for all human-powered vehicles.
The bicycle is the most efficient means of transportation ever devised by humans. See Science of Cycling: Human Power: page 1.
History
The first successful machines that resembled bicycles were invented in the early 1800s. The "draisine" of 1817 had two inline wheels connected to a wooden frame by forks, and the front wheel was steerable. It became rather popular, especially in England and America.
The draisine and machines like it went by a variety of names, such as hobby horse, dandy horse, biciped or swift walker. They were more like scooters than bicycles, because the only means of propulsion was to push against the ground.
By around 1840 cranks designed to be pedalled by the feet were attached to the front wheel on a machine called a "velocipede". Such machines became very popular after 1866, which is when Pierre Lallement obtained a US patent for a machine he called the "bisicle". Others called it a "boneshaker", an appropriate name for a contraption with steel-rimmed wooden wheels.
Solid rubber tires appeared in 1869 and improved the ride somewhat. The front wheel got bigger, and the rear wheel got smaller. A bicycle boom began. The first highwheeler or 'Ordinary' appeared in 1872. This was called a "Penny Farthing" in England (a penny representing the front wheel, and a much smaller coin, the farthing, representing the rear wheel).
Since a large wheel went farther for each turn of the cranks, and since the maximum pedalling speed was limited, the larger the wheel, the faster a rider could go. Some of the highwheelers had wheels nearly 60" in diameter. They were fast. They weren't particularly safe. The rider was way up in the air and travelling at a great speed. If he hit a bad spot in the road he could easily be thrown over the front wheel and be seriously injured or even killed. "Taking a header", which was not all that uncommon, was no joking matter.
In 1884, J. K. Starley invented the "safety bicycle" with wheels of moderate size and a chain drive. With the rider sitting far back on the bicycle, it was almost impossible to take a header on such a machine. With the front chainwheel larger than the rear sprocket, the rear wheel turned faster than the cranks, making it possible for a chain-driven bicycle to go fast even without a huge wheel.
J.P. Dunlop invented the pneumatic tire in 1888. This made for a much smoother ride.
The safety bicycles of 1890 were very much like today's bicycles. They had pneumatic tires similar in size to those on a modern bicycle, spoked wheels, a steel frame and a chain drive. About all they didn't have was a method of changing the gears.
Social & Historical aspect
Socially, the bicycle helped to strengthen the gene pool for rural workers. It tripled their courting radius on the one day per week they had off and thus was a factor in reducing rural inbreeding. The two-wheeled, diamond-frame safety bicycle (basically the same one we ride today) gave women unprecedented mobility, freed them from corsets, and contributed to their emancipation.
In cities, bicycles helped reduce the crowding in inner-city tenements by allowing workers to commute from single-family dwellings in suburbs. They helped reduce people's dependence on horses. They allowed people to travel in the country. They were three times as efficient as walking and three to four times as fast. Moreover, in terms of distance and speed traveled compared to energy consumed, the bicycle is the most efficient machine yet created.
On an historical note, the development of the modern bicycle had two important implications. First, manufacture of the double-diamond-frame safety bicycle required the development of advanced metalworking techniques to produce the frames, and components such as ball-bearings, washers and sprockets. These techniques later enabled skilled metalworkers and mechanics to develop the components that were used in early automobiles and aircraft. The best examples were the Wright Brothers, who got their start as bicycle mechanics.
The second major implication of the bicycle was the political organization of bicycle riders and enthusiasts in such groups as the League of American Wheelmen, in order to persuade local and state governments to create a system of well-maintained and mapped paved roads. Both the model of political organization and the roads themselves later facilitated the growth in the use of another type of wheeled vehicle, the automobile.
What we really need is a picture:
Technical aspect
And an article on bicycle repair and maintenance.
The picture should label the following parts: frame, top tube, down tube, seat tube, seat post, headset (head set?), handlebars, front forks, rear forks, chain stay, rear stay, wheel, wheel rim, wheel axle, spoke, spoke flange, brakes, brake levers, saddle, bottom bracket, crankshaft, cranks, pedal, chain, chainring, rear gears. Also the parts which vary a bit more: toe clips, cleats, gear changers, hub gears, derailleur gears, front gear block, rear gear block (aka cassette), mud guards, chain guards (both on the stay and around the chain), lights, panniers.
An article on bicycle brake systems might be useful.
Variations
Variations on the bicycle include:
- Penny-farthing
- more wheels: tricycles and so on
- one wheel: unicycle
- powered by more riders: tandem bicycle
- pedal & seating location: recumbent bicycle
- seatless: scooter
- used to transport taxi passengers: velotaxi or pedicab; trishaw
- push cycle
- Mountain bike
And maybe at least one reference to a sports science article that explains how cycling is the most efficient form of human powered transport.
Powered bicycles are also known as motorcycles, mopeds, and scooters.
Cycle trivia
It has often been observed that a fish is as likely to need a bicycle as a woman is to need a man. (http://www.geocities.com/SiliconValley/Vista/3255/herstory.htm)
A bike can be an insulting term for a locally-promiscuous woman as in the phrase "she's the town bike" (ie, "Everybody's taken her for a ride").