|
Spokes
Even the earliest bicycles used spokes of one sort or another.
In fact, even in ancient times many chariots and animal-drawn carts used
spokes. A spoked wheel can be made as strong as a solid one and have only
a fraction of the weight.While early spoked wheels were almost always made
out of wood, the bicycle wheels and spokes of today are made out steel or
aluminum or occasionally more exotic materials such as carbon composite
or ceramics.
Minimizing the weight of the wheels is extremely important
in bicycle design. Why does weight matter? Each time you push the pedals,
you have to accelerate the weight of the wheel both forward and around its
center. In other words, the wheel undergoes angular and straight motion
simultaneously. You can see this when you ride--the front tire of your bicycle
rotates while it moves forward along with you and the bike.
|
|
The Bicycle Craze of the Late 1800s
In the America of 1867 most people got around by on horse or on foot.
That was the year that the first factory-produced bicycles arrived on American
shores from Europe. Though the first high-wheeled "Ordinaries"
were quite expensive, costing about $100-150 (at a time when median annual
incomes hovered around $450), they were destined to become the rage. The
appeal of speed was strong, and bicycles offered mobility to young people
and to women, an unprecedented revolution in social freedom.
The craze caught fire with the production in 1887 of the Victor Bicycle,
a machine with two identically sized wheels and a chain drive much like
a modern bicycle. By 1885, over 400 bicycle factories were working non-stop
to keep up with skyrocketing demand. In 1895, Americans bought 2 million
bikes, one for every 27 people in the country. Cycling "academies,"
clubs, and professional races sprang up across the land.
But in 1902, Henry Ford introduced his "Tin Lizzy" automobile,
and the bicycle craze was quickly replaced with an obsession with the car.
The 1960s saw the beginning of a resurgence for the bicycle, and in 1984
Americans bought 14 million bikes, compared with 10 million cars.
|
|
