5755 x 3562 px | 48,7 x 30,2 cm | 19,2 x 11,9 inches | 300dpi
Informations supplémentaires:
The safety bicycle or low safety is a type of bicycle that became very popular beginning in the late 1880s, and is now the most common type of bicycle. The first safety, using a diamond frame, was invented by John Kemp Starley in 1885. "Safeties" are characterized by having two wheels of identical - or nearly identical - size, and a chain-driven rear wheel. The most popular form of the safety bicycle frame, consisting of two triangles, is known as a diamond frame. A similar but different frame used in safety bicycles is the step-through frame. The safety bicycle was a big improvement on the previous penny-farthing design which it replaced. The chain drive, coupling a large front cog (the chainring) to a small rear cog (the sprocket) to multiply the revolutions of the pedals, allowed for much smaller wheels, and replaced the need for the large, directly pedaled front wheel of the "penny-farthing" or "high ordinary". The smaller wheel gave a harder ride, thus hastening the replacement of solid tires with pneumatic ones. With the center of gravity low and between the wheels, rather than high and near the front hub, the Safety greatly diminished the danger of "taking a header" or long fall over the handlebars. This made braking more effective and cycling, previously the reserve of spry, daring young men, safer, and therefore much more popular, especially for women. The same basic design of bicycle is still in common use today.
