Bicycles
The bicycle began as a toy for the rich, evolved into a form of transportation, became a toy for children, and today is all of these things as well as the basis of a popular sport. Near the end of the 18th century, children sometimes played on a two–wheeled hobbyhorse propelled by pushing their feet on the ground. In 1790, a French count built an adult version that he called the célerifère ("quick strike"), which was briefly popular with the nobility. After the French Revolution and reign of Napoleon I, Joseph Nicéphore Niepce [French: 1765–1833], better known as the creator of the first photographs, redesigned the célerifère, which then (1816) became generally popular in Paris. Enthusiasm increased when an 1818 version was manufactured that could be steered by turning the front wheel.
Between pushes, a person balanced a célerifère without his or her feet touching the ground. In 1839, a Scottish blacksmith designed a version using treadles and levers, similar to the levers turning the wheels of a steam locomotive, that carried power to the back wheel as the rider balanced. French inventors had a better idea, which was to develop a speed advantage by using the foot to turn a crank handle that was attached to the front wheel. With each foot pushing a crank half way around, the pedal was born in 1861. Pedals turning in a relatively small circle rotated the much larger wheel, and the vehicles were called velocipedes ("swift–footed"). Since the ratio of pedal radius to front wheel radius determined speed, versions with very large front wheels were developed. But the giant front wheels made the velocipede unstable and accidents were common.
Also, only riders with long legs could reach the pedals.
In 1869, manufacturers began to use chains to allow a rider placed between the wheels to pedal the velocipede. In 1885, the safety bicycle, manufactured by the Rover Company in England, became the standard, with two equal–sized wheels and pedal power transmitted by a covered chain to the back wheel. Air–filled rubber tires were invented in 1888 and gears became available as early as 1890.
Bicycles prepared the way for automobiles, especially by necessitating better roads. People trained as bicycle mechanics became the inventors of the automobile, and bicycle manufacturers switched to making cars.
In the latter part of the 20th century, the sport of bicycle racing led to many improvements in bicycles. The environmental movement promoted the use of bicycles as clean, energy–efficient transportation. Specialized bicycles were developed for riding on trails and up mountains.