Thứ Tư, 6 tháng 8, 2014

Technical aspects

Construction
See also: Motorcycle components and Motorcycle design
Motorcycle construction is the engineering, manufacturing, and assembly of components and systems for a motorcycle which results in the performance, cost, and aesthetics desired by the designer. With some exceptions, construction of modern mass-produced motorcycles has standardised on a steel or aluminium frame, telescopic forks holding the front wheel, and disc brakes. Some other body parts, designed for either aesthetic or performance reasons may be added. A petrol powered engine typically consisting of between one and four cylinders (and less commonly, up to eight cylinders) coupled to a manual five- or six-speed sequential transmission drives the swingarm-mounted rear wheel by a chain, driveshaft or belt.

Fuel economy
Motorcycle fuel economy varies greatly with engine displacement and riding style ranging from a low of 29 mpg-US (8.1 L/100 km; 35 mpg-imp) reported by a Honda VTR1000F rider, to 107 mpg-US (2.2 L/100 km; 129 mpg-imp) reported for the Verucci Nitro 50 cc scooter. A specially designed Matzu Matsuzawa Honda XL125 achieved 470 mpg-US (0.50 L/100 km; 560 mpg-imp) "on real highways – in real conditions." Due to low engine displacements (100 cc–200 cc), and high power-to-mass ratios, motorcycles offer good fuel economy. Under conditions of fuel scarcity like 1950s Britain and modern developing nations, motorcycles claim large shares of the vehicle market.

Electric motorcycles
Main article: Electric motorcycle
Very high fuel economy equivalents are often derived by electric motorcycles. Electric motorcycles are nearly silent, zero-emission electric motor-driven vehicles. Operating range and top speed are limited by battery technology.[citation needed] Fuel cells and petroleum-electric hybrids are also under development to extend the range and improve performance of the electric drive system.
Reliability
A 2013 survey of 4,424 readers of the US Consumer Reports magazine collected reliability data on 4,680 motorcycles purchased new from 2009 to 2012. The most common problem areas were accessories, brakes, electrical (including starters, charging, ignition), and fuel systems, and the types of motorcycles with the greatest problems were touring, off road/dual sport, sport-touring, and cruisers. There were not enough sport bikes in the survey for a statistically significant conclusion, though the data hinted at reliability as good as cruisers. These results may be partially explained by accessories including such equipment as fairings, luggage, and auxiliary lighting, which are frequently added to touring, adventure touring/dual sport and sport touring bikes. Trouble with fuel systems is often the result of improper winter storage, and brake problems may also be due to poor maintenance.


 Of the five brands with enough data to draw conclusions, Honda, Kawasaki and Yamaha were statistically tied, with 11 to 14% of those bikes in the survey experiencing major repairs. Harley-Davidsons had a rate of 24%, while BMWs did worst, with 30% of those needing major repairs. There were not enough Triumph and Suzuki motorcycles surveyed for a statistically sound conclusion, though it appeared Suzukis were as reliable as the other three Japanese brands while Triumphs were comparable to Harley-Davidson and BMW. Three fourths of the repairs in the survey cost less than US$ 200 and two thirds of the motorcycles were repaired in less than two days. In spite of their relatively worse reliability in this survey, Harley-Davidson and BMW owners showed the greatest owner satisfaction, and three fourths of them said they would buy the same bike again, followed by 72% of Honda owners and 60 to 63% of Kawasaki and Yamaha owners.

Dynamics

Racing motorcycles leaning in a turn.
Main article: Bicycle and motorcycle dynamics
Different types of motorcycles have different dynamics and these play a role in how a motorcycle performs in given conditions. For example, one with a longer wheelbase provides the feeling of more stability by responding less to disturbances. Motorcycle tyres have a large influence over handling.

Motorcycles must be leaned in order to make turns. This lean is induced by the method known as countersteering, in which the rider momentarily steers the handlebars in the direction opposite of the desired turn. This practice is counter-intuitive and therefore often confusing to novices – and even many experienced motorcyclists.

Such short wheelbase motorcycles as sport bikes can generate enough torque at the rear wheel, and enough stopping force at the front wheel, to lift the opposite wheel off the road. These actions, if performed on purpose, are known as wheelies and stoppies respectively. If carried past the point of recovery the resulting upset is known as an "endo" (short for "end-over-end"), or "looping" the vehicle.
Accessories
Main article: Motorcycle accessories
Various features and accessories may be attached to a motorcycle either as OEM (factory-fitted) or after-market. Such accessories are selected by the owner to enhance the motorcycle's appearance, safety, performance, or comfort, and may include anything from mobile electronics to sidecars and trailers.

Thứ Hai, 4 tháng 8, 2014

Popularity

Statistically, there is a large difference between the car-dominated developed world, and the more populous developing world where cars are less common than motorcycles. In the developed world, motorcycles are mainly a luxury good, used mostly for recreation, as a lifestyle accessory, or a symbol of personal identity, while in developing countries motorcycles are overwhelmingly utilitarian. Motorcycles are one of the most affordable forms of motorised transport and, for most of the world's population, they are the most familiar type of motor vehicle. While North America, Europe, and Japan are car-centric cultures where motorcycles are uncommon, the non-car-centric cultures of India, China, and Southeast Asia account for more than half of the world's population, and in those places two-wheelers outnumber four wheeled vehicles. About 200 million motorcycles, including mopeds, motor scooters, motorised bicycles, and other powered two and three-wheelers, are in use worldwide, or about 33 motorcycles per 1000 people. By comparison, there are about 1 billion cars in the world, or about 141 per 1000 people, with about one third in service in Japan and the United States.

India, with an estimated 37 million motorcycles/mopeds, was home to the largest number of motorised two wheelers in the world. China came a close second with 34 million motorcycles/mopeds in 2002. As the middle class in India, China, and other developing countries grows, they are repeating the transition from motorcycles to cars that took place in the US in the years after World War I, and in Europe following World War II, and the role of motorcycling is changing from a transport necessity to a leisure activity, and the motorcycle is changing from a family's primary motor vehicle to a second or third vehicle.

Demographics


Number of motorcycles vs number of cars by country. Size of pie indicates population. 2002 estimates.


Millions of cars (light blue) and motorcycles (dark blue) in the top 20 countries with the most motorcycles. Population in red. 2002 estimates.


Motorbikes are the primary form of transportation in Vietnam.
In numerous cultures, motorcycles are the primary means of motorised transport. According to the Taiwanese government, for example, "the number of automobiles per ten thousand population is around 2,500, and the number of motorcycles is about 5,000." In places such as Vietnam, motorised traffic consist of mostly motorbikes due to a lack of public transport and low income levels that put automobiles out of reach for many.

The four largest motorcycle markets in the world are all in Asia: China, India, Indonesia, and Vietnam. The motorcycle is also popular in Brazil's frontier towns. Amid the global economic downturn of 2008, the motorcycle market grew by 6.5%. In China, the number of motorcycles in use increased from 34 million in 2002 to 54 million in 2006, with annual production of 22 million units.

Recent years have seen an increase in the popularity of motorcycles elsewhere. In the USA, registrations increased by 51% between 2000 and 2005. This is mainly attributed to increasing fuel prices and urban congestion. A Consumer Reports subscribers' survey of mainly United States motorcycle and scooter owners reported that they rode an average of only 1,000 miles (1,600 km) per year, 82% for recreation and 38% for commuting. Americans put 10,000–12,000 miles (16,000–19,000 km) per year on their cars and light trucks.

As motorcyclists age, there is a tendency for riders to choose touring bikes over sports bikes.

Use


Milk delivery in Karnal, India


A couple ride on a motorcycle in Udaipur, India. Annual sales of motorcycles in India are expected to exceed 10 million by 2010.
While people choose to ride motorcycles for various reasons, those reasons are increasingly practical, with riders opting for a powered two-wheeler as a cost-efficient alternative to infrequent and expensive public transport systems, or as a means of avoiding or reducing the effects of urban congestion. Where permitted, lane splitting, which is also known as filtering, allows motorcycles to move between vehicles in slow or stationary traffic.

In the UK, motorcycles are exempt from the £10 per day London congestion charge that other vehicles must pay to enter the city during the day. Motorcycles are also exempt from toll charges at such river crossings as the Severn Bridge, Dartford Crossing, and Mersey Tunnels. Such cities as Bristol provide dedicated free parking and allow motorcycles to use bus lanes. In the United States, motorcycles may use high-occupancy vehicle lanes in accordance with federal law  and pay a lesser fee on some toll roads. Other countries have similar policies.

In New Zealand, motorcycle riders need not pay for parking that is controlled by a barrier arm; the arm occupies less than the entire width of the lane, and the motorcyclist simply rides around it. Many car parks that are thus controlled so supply special areas for motorcycles to park as to save space.

In many cities that have serious parking challenges for cars, such as Melbourne, Australia, motorcycles are generally permitted to park on the sidewalk, rather than occupy a space on the street which might otherwise be used by a car.[citation needed]

Chủ Nhật, 3 tháng 8, 2014

History

Experimentation and invention
Butler's Patent Velocycle
The first commercial design for a self-propelled bicycle was a three-wheel design called the Butler Petrol Cycle, conceived of Edward Butler in England in 1884. He exhibited his plans for the vehicle at the Stanley Cycle Show in London in 1884. The vehicle was built by the Merryweather Fire Engine company in Greenwich, in 1888. The Butler Petrol Cycle (first recorded use of the term) was a three-wheeled vehicle, with the rear wheel directly driven by a 5/8hp (466W) 600 cc (40 in3; 2¼×5-inch {57×127-mm}) flat twin four stroke engine (with magneto ignition replaced by coil and battery), equipped with rotary valves and a float-fed carburettor (five years before Maybach), and Ackermann steering, all of which were state of the art at the time. Starting was by compressed air. The engine was liquid-cooled, with a radiator over the rear driving wheel. Speed was controlled by means of a throttle valve lever. No braking system was fitted; the vehicle was stopped by raising and lowering the rear driving wheel using a foot-operated lever; the weight of the machine was then borne by two small castor wheels. The driver was seated between the front wheels. It wasn't, however, a success, as Butler failed to find sufficient financial backing.

Replica of the Daimler-Maybach Reitwagen.
Another early internal combustion, petroleum fueled motorcycle was the Daimler Reitwagen. It was designed and built by the German inventors Gottlieb Daimler and Wilhelm Maybach in Bad Cannstatt, Germany in 1885. This vehicle was unlike either the safety bicycles or the boneshaker bicycles of the era in that it had zero degrees of steering axis angle and no fork offset, and thus did not use the principles of bicycle and motorcycle dynamics developed nearly 70 years earlier. Instead, it relied on two outrigger wheels to remain upright while turning. The inventors called their invention the Reitwagen ("riding car"). It was designed as an expedient testbed for their new engine, rather than a true prototype vehicle.

Many authorities who exclude steam powered, electric or diesel two-wheelers from the definition of a motorcycle, credit the Daimler Reitwagen as the world's first motorcycle.

If a two-wheeled vehicle with steam propulsion is considered a motorcycle, then the first was the French Michaux-Perreaux steam velocipede of 1868. This was followed by the American Roper steam velocipede of 1869, built by Sylvester H. Roper Roxbury, Massachusetts. Roper demonstrated his machine at fairs and circuses in the eastern U.S. in 1867, and built a total of 10 examples.

Summary of early inventions
Year Vehicle Number of wheels Inventor Engine type Notes
1867–1868 Michaux-Perreaux steam velocipede 2 Pierre Michaux
Louis-Guillaume Perreaux Steam
One made
1867–1868 Roper steam velocipede 2 Sylvester Roper Steam
Ten made
1884 Butler Petrol Cycle 3 (plus 2 castors) Edward Butler Petroleum internal-combustion
1885 Reitwagen 2 (plus 2 outriggers) Gottlieb Daimler
Wilhelm Maybach Petroleum internal-combustion
One made
1894 Hildebrand & Wolfmüller 2 Heinrich Hidebrand
Wilhelm Hidebrand
Alois Wolfmüller Petroleum internal-combustion
Modern configuration
First mass-produced motorcycle
First machine to be called "motorcycle"
First motorcycle companies


Diagram of 1894 Hildebrand & Wolfmüller.
In 1894, Hildebrand & Wolfmüller became the first series production motorcycle, and the first to be called a motorcycle (German: Motorrad). Excelsior Motor Company, originally a bicycle manufacturing company based in Coventry, England, began production of their first motorcycle model in 1896. The first production motorcycle in the US was the Orient-Aster, built by Charles Metz in 1898 at his factory in Waltham, Massachusetts.

In the early period of motorcycle history, many producers of bicycles adapted their designs to accommodate the new internal combustion engine. As the engines became more powerful and designs outgrew the bicycle origins, the number of motorcycle producers increased. Many of the nineteenth century inventors who worked on early motorcycles often moved on to other inventions. Daimler and Roper, for example, both went on to develop automobiles.

At the turn of the century the first major mass-production firms were set up. In 1898, Triumph Motorcycles in England began producing motorbikes, and by 1903 it was producing over 500 bikes. Other British firms were Royal Enfield, Norton and Birmingham Small Arms Company who began motorbike production in 1899, 1902 and 1910, respectively. Indian began production in 1901 and Harley Davidson was established two years later. By the outbreak of the First World War, the largest motorcycle manufacturer in the world was Indian, producing over 20,000 bikes per year.

First World War

Triumph Motorcycles Model H, mass-produced for the war effort and notable for its reliability
During the First World War, motorbike production was greatly ramped up for the war effort to supply effective communications with front line troops. Messengers on horses were replaced with despatch riders on motorcycles carrying messages, performing reconnaissance personnel and acting as a military police. American company Harley-Davidson was devoting over 50% of its factory output toward military contract by the end of the war. The British company Triumph Motorcycles sold more than 30,000 of its Triumph Type H model to allied forces during the war. With the rear wheel driven by a belt, the Model H was fitted with a 499 cc air-cooled four-stroke single-cylinder engine. It was also the first Triumph not to be fitted with pedals, so was a true motorcycle.

The Model H in particular, is regarded by many as having been the first "modern motorcycle". Introduced in 1915 it had a 550 cc side-valve four-stroke engine with a three-speed gearbox and belt transmission. It was so popular with its users that it was nicknamed the "Trusty Triumph."

Postwar
By 1920, Harley-Davidson was the largest manufacturer, with their motorcycles being sold by dealers in 67 countries. By the late 1920s or early 1930s, DKW in Germany took over as the largest manufacturer.



NSU Sportmax streamlined motorcycle, 250 cc class winner of the 1955 Grand Prix season
After World War II, the Birmingham Small Arms Company became the largest producer of motorcycles in the world, producing up to 75,000 bikes per year in the 1950s.[citation needed] The German company NSU held the position of largest manufacturer from 1955 until the 1970s.[citation needed]

In the 1950s, streamlining began to play an increasing part in the development of racing motorcycles and the "dustbin fairing" held out the possibility of radical changes to motorcycle design. NSU and Moto Guzzi were in the vanguard of this development, both producing very radical designs well ahead of their time. NSU produced the most advanced design, but after the deaths of four NSU riders in the 1954–1956 seasons, they abandoned further development and quit Grand Prix motorcycle racing.

Moto Guzzi produced competitive race machines, and by 1957 nearly all the Grand Prix races were being won by streamlined machines.[citation needed] The following year, 1958, full enclosure fairings were banned from racing by the FIM in the light of the safety concerns.

From the 1960s through the 1990s, small two-stroke motorcycles were popular worldwide, partly as a result of East German Walter Kaaden's engine work in the 1950s.

Today


Royal Enfield Bullet, Rewalsar Lake, Himachel Pradesh, India. 2010
In the 21st century, the motorcycle industry is mainly dominated by Japanese companies. In addition to the large capacity motorcycles, there is a large market in smaller capacity (less than 300 cc) motorcycles, mostly concentrated in Asian and African countries. An example is the 1958 Honda Super Cub, which went on to become the biggest selling vehicle of all time, with its 60 millionth unit produced in April 2008. Today, this area is dominated by mostly Indian companies with Hero MotoCorp emerging as the world's largest manufacturer of two wheelers. Its Splendor model has sold more than 8.5 million to date. Other major producers are Bajaj and TVS Motors.

Thứ Bảy, 2 tháng 8, 2014

Motorcycle

A motorcycle (also called a motorbike, bike, moto or cycle) is a two or three wheeled motor vehicle. Motorcycle design varies greatly to suit a range of different purposes: long distance travel, commuting, cruising, sport including racing, and off-road riding.

In 1894, Hildebrand & Wolfmüller became the first series production motorcycle, and the first to be called a motorcycle. In 2012, the three top motorcycle producers globally by volume were Honda, Bajaj Auto, and Hero MotoCorp.

In the developed world, motorcycles are mainly a luxury good, used mostly for recreation, as a lifestyle accessory, or a symbol of personal identity, while in developing countries motorcycles are overwhelmingly utilitarian due to lower prices and greater fuel economy. And as such most of the world's motorcycles, 58%, are in the developing countries of Southern and Eastern Asia, and the Asia Pacific, excluding Japan which is one of the world's major car users.

Motorcycles have a higher rate of fatal accidents than automobiles or trucks and buses. United States Department of Transportation data for 2005 from the Fatality Analysis Reporting System show that for passenger cars, 18.62 fatal crashes occur per 100,000 registered vehicles. For motorcycles this figure is higher at 75.19 per 100,000 registered vehicles – four times higher than for cars. The same data shows that the number of fatalities per vehicle mile travelled is 28 times higher for motorcycles than for cars (37 times higher in 2007).