bicycle
The ‘hobby horse’ and the ‘bone-shaker’ were two of the earliest bicycles designed. From pre-pedal machines such as the ‘hobby horse’ (designed in the late 18th century) came the introduction of the pedal with the ‘bone-shaker’ bicycle.
Pedal-driven two-wheeled vehicle used in cycling. It consists of a metal frame mounted on two large wire-spoked wheels, with handlebars in front and a seat between the front and back wheels. The bicycle is an energy-efficient, nonpolluting form of transport, and it is estimated that 800 million bicycles are in use throughout the world – outnumbering cars three to one. China, India, Denmark, and the Netherlands are countries with a high use of bicycles. More than 10% of road spending in the Netherlands is on cycleways and bicycle parking.
History
The first bicycle was probably created by the German Baron Karl de Drais de Sauerbrun, and exhibited in Paris
c. 1818. It was a form of hobby-horse (though there are versions of the hobby-horse that date back even earlier) that had to be propelled by pushing the feet against the ground. The first treadle-propelled cycle was designed by the Scottish blacksmith Kirkpatrick Macmillan in around 1839. The Rover ‘safety bike’ of 1885 may be considered the forerunner of the modern bicycle, with a chain and sprocket drive on the rear wheel. By the end of the 19th century wire wheels, metal frames (replacing wood), and pneumatic tyres (invented by the Scottish veterinary surgeon John B Dunlop in 1888) had been added. Among the bicycles of that time was the front-wheel-driven penny farthing with a large front wheel.
Technology
Recent technological developments have been related to reducing wind resistance caused by the frontal area and the turbulent drag of the bicycle. Most of an Olympic cyclist's energy is taken up in fighting wind resistance in a sprint. The first major innovation was the solid wheel, first used in competitive cycling 1984, but originally patented as long ago as 1878. Further developments include handlebars that allow the cyclist to crouch and use the shape of the hands and forearms to divert air away from the chest. Modern racing bicycles now have a monocoque structure produced by laying carbon fibre around an internal mould and then baking them in an oven. Using all these developments, Chris Boardman set a speed record of 54.4 kph (34 mph) on his way to winning a gold medal at the 1992 Barcelona Olympics. To manufacture a bicycle requires only 1% of the energy and materials used to build a car.
Mountain bikes
Special bicycles with fat tyres, a strong frame, and more gears than conventional bicycles, designed to be ridden on rough terrain, have become popular since the 1970s; the first purpose-built mountain bikes went on sale in 1979. Mountain biking became an Olympic sport in 1996; there are also annual world championships.
| The USA observed ‘Bike-to-Work Day’ on 18 May 1999. Statistics show that the number of Americans riding bicycles increased from 67 million in 1991 to 81 million in 1998, but fewer than 5% of work-related trips are made by bicycles. |
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