Monday, November 22, 2004

A bicycle

A bicycle, or bike, is a pedal-driven land vehicle with two wheels arranged in line. First introduced in 19th century Europe, it evolved quickly into its current basic design. With over one billion in the world today, bicycles provide the principal means of transportation in many regions and a popular form of recreation in others.
No specific time or person can be identified with the invention of the bicycle. Its earliest known forebears were called velocipedes, and included the scooter-like dandy horses of the French Comte de Sivrac, dating to 1790, and German tax collector Karl von Drais, who rode his 1816 machine on his rounds. All the aforementioned were literally pushbikes, in that they were powered by the action of the rider's feet against the ground. A Scottish blacksmith, Kirkpatrick MacMillan, is credited with adding a treadle drive mechanism in 1840, for the first time enabling the rider to lift his feet off the ground. MacMillan is also reported to have been the first cyclist to receive a traffic fine, after knocking over a pedestrian.
In the 1850s and 1860s, Frenchman Ernest Michaux and his pupil Pierre Lalloment placed pedals on a enlarged front wheel. Their creation, aptly called the Boneshaker, featured a heavy steel frame on which were mounted wooden wheels with iron tires. The boneshaker was further refined by James Starley in the 1870's. He mounted the seat more squarely over the pedals, so that the rider could push more firmly, and further enlarged the front wheel to increase the potential speed. His machine became known as an ordinary. British cyclists likened the disparity in size of the two wheels to their coinage, nicknaming it the "penny-farthing". This model was difficult to ride however, and the high seat and poor weight distribution made for dangerous falls.
The dwarf ordinary which followed addressed some of these faults, by reducing the front wheel diameter and setting the saddle farther back. Pedaling was accomplished by levers or off-set pedals, and gearing was added, thus compensating for speed loss. However, having to both pedal and steer via the front wheel remained a problem. Starley's nephew, J. K. Starley, J. H. Lawson, and Shergold solved this problem by introducing rear wheel drive, using a roller chain. Starley's 1885 Rover is usually described as the first recognisably modern bicycle. These dwarf safeties, or safety bicycles, were so-named for their smaller front wheels, better weight distibution, and lower seating height. Soon the seat tube was added, creating the double-triangle, diamond frame of the modern bike.


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