Ball bearings and pneumatic tyres were bicycle parts before cars borrowed them
Long before the motor car, bicycle makers had worked out ball bearings, pneumatic tyres, chain-driven sprockets and tension-spoked wheels. All four later proved vital to automobiles. The machine that pioneered them has barely changed shape since the chain-driven safety bicycle appeared around 1885, and more than a billion now exist.
The word itself is older than the machine most people picture. French used bicycle in 1828 for a two-wheeled horse-drawn chaise, and English print first carried it in 1868, when The Daily News described bysicles and trysicles rolling along the Champs Elysées. For a while the term overlapped with velocipede, the earlier design the bicycle improved upon.
Staying upright is a matter of steering. A rider constantly nudges the front wheel so that the combined centre of mass stays over the tyres, and to turn, the bike and rider must first lean. That lean comes from countersteering, a brief push on the handlebars in the opposite direction, often done without the rider noticing. Under certain conditions the bicycle can even steer itself upright.
Few machines waste so little effort. Up to 99 percent of the energy pushed into the pedals reaches the wheels, though gears can shave off 10 to 15 percent. At 16 to 24 kilometres an hour, a cyclist spends only about as much power as walking, and covering a given distance takes some 80 percent less energy than going on foot. Speed is where cost climbs, because air drag grows with the square of velocity, and an upright body produces about three quarters of it.
That drag explains an odd piece of racing history. Recumbent bicycles, where the rider leans back with pedals near seat height, slice through the air far better than upright designs, and the fastest bicycle in the world is a recumbent. The Union Cycliste Internationale banned them from competition in 1934. Frame materials have tracked aircraft, moving from alloy steel in the late 1930s to aluminium in the 1980s, while bamboo frames date back to 1894.
Source: Bicycle
