A bicycle or just cycle is a human-powered vehicle driven by pedals.
It has two wheels which are attached to a metal or in some cases hard
plastic frame, one at the front and the other at the back.
History of a bicycle
The bicycle was first introduced in Europe in the 19th century.
Presently their number is exceeding one billion throughout the world.
They are used as a principal mode of transportation in some areas of
the world, especially Netherlands and China. They have also developed
as a very popular form of entertainment and recreation. Other fields of
human activities that they have been adopted are adult fitness,
children`s toys, police and military applications, cycle sports and
courier services. Thus over the period of time the humble bicycle has
assumed quite a few roles!
The basic configuration and shape of a common bicycle has been
altered very slightly since the first model driven by chains was
developed back in 1885. However, some subtle details have been made
better with the growing use of computer and improvement in material
technology. Using modern technologies have made it possible to produce
specialized designs for different kinds and uses of cycling.
Parts and Construction of a Typical Bicycle
Wheels - it is the most important part of any vehicle. The initial
wheels used a wooden hub with a steel axle, spokes made of wood and an
iron tire which is fitted on the outside. The wheels used today have a
metal hub, metallic wire spokes, a metal rim to hold the spokes and a
pneumatic rubber tire on the outside. Another important part of the
wheel are the bearings which allows free movement of the hub on the
axle.
Frame - most of the bicycles used today has the diamond frame. It`s
made up of two triangles, the front and the rear. The front triangle
has the top tube, head tube, seat tube and down tube. Head tube is the
part containing the headset of bearing to allow smooth steering, the
top tube connects to the seat, and the down tube connects the head tube
and bottom bracket. The rear triangle has the seat tube, seat stays and
paired chain stays.
Drivetrain - it consists of the pedals, which rotates the crank
arms, which in turn are attached to a sprocket or chainrings which
drives the chain and makes the rear wheel rotate.
Seating and Steering - steering is made possible using the
handlebars which turns the front wheel. For seating there are saddles
on the top of the frame. The seating can be designed for comfort or to
make cycling smoother and faster.
Brakes - the brakes used in modern bicycles are either rim brakes
that uses pads to compress the wheel from 2 sides and stopping it,
internal hub brakes that has the pads inside the hubs or disc brakes.
Braking in bicycles is hand-operated by pressing the brake levers
installed on the handlebars on either side.
Suspension - it is the system incorporated to make the cycling experience smoother.
Accessories - parts like mudguards to avoid spray from puddles,
chain guards to save clothes from oils, kick stands to keep the bicycle
upright while parked have become permanent features of a bicycle. Other
accessories like front baskets, rear racks, space for head lamp, a
pump, helmets, tool kit etc are also available as per ordered.
The use and development of bicycles have affected mankind in a
bigger way than it seems. It has affected history in both industrial
and cultural realms. In the initial years, bicycles and its
construction were dependent on the technology that existed; more
recently, its technology in turn has given forth ideas in different
areas
