Motorcycle is a two- or three-wheeled vehicle powered by a gasoline engine mounted midway between the front and rear wheels. A motorcycle has a much heavier and stronger frame than a bicycle, the vehicle from which it was developed. People in many parts of the world use motorcycles for transportation or ride them for recreation and sport. Many police departments use motorcycles for pursuit and traffic control because these vehicles can be maneuvered easily through traffic. Some fire departments use motorcycles to transport medical personnel to accident scenes. Many motorcyclists call their machines “bikes.”
In most countries, motor vehicle laws affect the operation of motorcycles as well as of automobiles and other kinds of vehicles. Many countries require cyclists to have a motorcycle operator’s license, for which a person must pass a test. Neither the United States nor Canada has a national requirement, but most states and provinces require licenses. One test used by many U.S. licensing agencies is the Motorcycle Operator Skills Test (MOST). To pass this test, cyclists must demonstrate skill in handling a motorcycle. Many states and provinces, as well as many countries, require cyclists to wear safety helmets and protection for their eyes.
Motorcycling is popular throughout the world. In regions where gasoline is usually more expensive, such as East Asia, Europe, and South America, motorcycles are regarded as convenient and inexpensive transportation. In the United States and Canada, motorcycles are widely used for recreation, as well as for transportation to jobs. In urban areas, motorcycles help to reduce traffic congestion and air pollution.
Kinds of motorcycles.
Manufacturers produce motorcycles in a variety of sizes, types, and weights. The two main kinds are (1) those designed primarily for use on streets and other paved surfaces, and (2) those intended chiefly for off-road riding. The first group consists of street and touring bikes and motor scooters. The second group includes trail bikes and a variety of other related off-road vehicles.
Street bikes
are used on roads and highways for short or long trips and for in-town riding. They weigh from 235 to 500 pounds (110 to 230 kilograms) and can travel at all legal highway speeds.
Touring bikes
are street bikes that carry special equipment for long-distance travel. For example, many touring bikes are equipped with windshields to provide extra protection against the wind, and compartments to carry luggage. Touring bikes weigh from 500 to 900 pounds (230 to 410 kilograms) and enable riders to travel long distances more comfortably than they could on street bikes.
Trail bikes
can travel on rough country trails, climb hills, and cross streams. They have deeply grooved tires that provide traction on gravel and other rough surfaces. They weigh from 150 to 250 pounds (68 to 110 kilograms).
Motor scooters
are primarily designed for use at lower speeds in urban settings. The driver of a motor scooter sits with both feet on a floorboard.
Minibikes and minicycles
have motorcycle-type engines but weigh less and are more compact than most motorcycles. They are not built for use on paved roads.
Motorbikes
include mopeds << MOH pehdz >> , which are started by pedaling. Mopeds have an automatic transmission, and can reach a speed of 30 miles (48 kilometers) per hour.
The parts of a motorcycle.
A motorcycle has five major parts: (1) the engine, (2) the transmission system, (3) the wheels, (4) the brakes, and (5) the controls. A frame of steel or chrome tubing holds them together.
The engine
of a motorcycle has one to six cylinders. It operates on either a two-stroke or four-stroke cycle (see Gasoline engine (Cycle) ).
The transmission system
of most motorcycles consists of four, five, or six gears. Racing models may have as many as eight speeds, and some small models have as few as two.
The wheels.
Most street motorcycles have steel- or aluminum-rimmed wheels with tubeless tires similar to those on automobiles. However, many off-road bikes have rubber tubes inside the tire to hold compressed air. Motorcycle tires have a rounded tread pattern that provides the traction needed for leaning through turns. The front fork, an extension of the frame, helps hold the front wheel in place. It serves as a suspension system that cushions the rider against bumps. A rear swing arm allows the rear wheel to move up and down, providing additional stability when riding over bumps.
The brakes.
A motorcycle has front- and rear-wheel brakes, which work separately. The front brake supplies most of the stopping force.
The controls.
The rider uses various hand and foot controls to operate the motorcycle. Most modern bikes have an electric starter. A hand twist grip controls the throttle, which regulates the engine speed. A hand lever on the left handlebar operates the clutch. A hand lever on the right handlebar controls the front brake, and a foot pedal controls the rear brake. Most motorcycles have a second foot control for shifting gears.
Motorcycle safety.
Organizations in many countries have programs that promote motorcycle safety. The Motorcycle Safety Foundation in the United States and the Canada Safety Council have developed motorcycle safety courses. These courses, which are offered by many community colleges, high schools, and police departments, are designed to develop good riding habits. They also stress the importance of proper cycling clothes, such as a helmet, goggles, gloves, and boots.
Motorcycling as a sport
enables riders to compete in such events as dirt-track races, enduros (endurance races), and motocross races. Motocross racing is the most popular type of motorcycle competition. It includes races run on rugged courses that have jumps, hills, and other obstacles.
The Federation Internationale de Motocyclisme governs motorcycle competition at the world level. The federation, which has headquarters in Mies, Switzerland, includes more than 80 national affiliates. The U.S. affiliate, the American Motorcyclist Association (AMA), governs most motorcycle competition in the United States. It has headquarters in Pickerington, Ohio. The AMA sanctions (approves) a number of annual races. A point system established by the AMA determines a racing champion each year. Cyclists receive points for winning official races or for placing high in the events. The racer who earns the most points becomes Grand National Champion.
History.
The first gasoline-powered motorcycle was invented in 1885 by Gottlieb Daimler, a German engineer. He attached a four-stroke piston engine to a wooden bicycle frame. For the next few years, motorcycles remained largely experimental. During the early 1900’s, they developed into useful vehicles. Today’s motorcycles have the same general appearance as earlier models. But modern bikes are easier to handle, and they have stronger frames, more powerful engines, and more efficient brakes.
See also Daimler, Gottlieb; Dirt bike; Maybach, Wilhelm; Scooter; Surtees, John.
