2009-02-01T02:35:00.000-08:00

Motorcycle

A motorcycle (also called a motorbicycle, motorbike, bike, or cycle) is a single-track, two-wheeled motor vehicle powered by an engine. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions. In many parts of the world, motorcycles are among the least expensive and most widespread forms of motorised transport. Traditionally, motorcycles used a lot less fuel than cars but modern engines and aerodynamics have largely eliminated this advantage for familiar western motorcycles used for leisure and touring.

History

Replica of the Daimler-Maybach Reitwagen

Arguably, the first motorcycle was designed and built by the German inventors Gottlieb Daimler and Wilhelm Maybach in Bad Cannstatt (since 1905 a city district of Stuttgart) in 1885. The first petroleum-powered vehicle, it was essentially a motorised bicycle, although the inventors called their invention the Reitwagen ("riding car"). However, if a two-wheeled vehicle with steam propulsion is considered a motorcycle, then the first one may have been American. One such machine was demonstrated at fairs and circuses in the eastern U.S. in 1867, built by Sylvester Howard Roper of Roxbury, Massachusetts.
In 1894, Hildebrand & Wolfmüller became the first motorcycle available for purchase. 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.
Until the First World War, the largest motorcycle manufacturer in the world was Indian, producing over 20,000 bikes per year. By 1920, this honour went to Harley-Davidson, with their motorcycles being sold by dealers in 67 countries. In 1928, DKW took over as the largest manufacturer.
After the Second World War, the BSA Group became the largest producer of motorcycles in the world, producing up to 75,000 bikes per year in the 1950s. The German company NSU Motorenwerke AG held the position of largest manufacturer from 1955 until the 1970s.
In the 1950s, streamlining began to play an increasing part in the development of racing motorcycles and 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 because of 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.
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, the Japanese manufacturers, Honda, Kawasaki, Suzuki, and Yamaha dominate the motorcycle industry, although Harley-Davidson still maintains a high degree of popularity in the United States. Apart from these high capacity motorcycles, there is a very huge market for low capacity (less than 300 cc) motorcycles, mostly concentrated in Asian and African countries. This area is dominated by mostly Indian companies with Hero Honda being the world's largest manufacturer of two wheelers. Its Hero Honda Splendor model is the highest selling motorcycle in automotive history, having sold more than 8.5 million to date.
Recent years have also seen a resurgence in the popularity of several other brands sold in the U.S. market, including BMW, KTM, Triumph, Aprilia, Moto-Guzzi, MV Agusta and Ducati.
Outside of the U.S., these brands have enjoyed continued and sustained success, although Triumph, for example, has been re-incarnated from its former self into a modern world-class manufacturer. In overall numbers, however, the Chinese currently manufacture and sell more motorcycles than any other country and exports are rising.
Additionally, the small-capacity scooter is very popular through most of the world. The Piaggio group of Italy, for example, is one of the world's largest producers of two-wheeled vehicles.
Technical aspects
Construction
Motorcycle construction is the engineering, manufacturing, and assembly of components and systems for a motorcycle which results in 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. 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 benefits from the relatively small mass of the vehicle. This, of course, relates to how the motorcycle is used. One person on a small motorcycle travelling a short distance is generally very economical. However a large motorcycle generally has bad aerodynamics compared with a typical car, poor aerodynamics of exposed passengers and engines designed for goals other than fuel economy can work to reduce these benefits. Riding style has a large effect on fuel economy.
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 (2.20 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 lower engine displacements (100 cc–200 cc), motorcycles in developing countries offer good fuel economy. In the Indian market, the second most selling company, Bajaj, offers two models with superior fuel economy: XCD 125 and Platina. Both are 125 cc motorbikes with a company-claimed fuel economy of 109 km/l and 111 km/l, respectively.
Dynamics
Different types of motorcycles have different dynamics and these play a role in how a motorcycle performs in given conditions. For example, a shorter wheelbase would generally make a bike lean faster and would be quicker around corners compared to a longer wheelbase. Longer wheelbase on the other hand provides more stability in a straight line.
Motorcycles must be leaned in order to make turns. This lean is induced by the method known as countersteering, in which the rider steers the handlebars in the direction opposite of the desired turn. Because it is counter-intuitive this practice is often very confusing to novices—and even to many experienced motorcyclists.
Short wheelbase motorcycles, such 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 pavement. 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 "looping" the vehicle.
Additions
Various features and accessories may be attached to a motorcycle either from the factory or by users.
A plastic or fibreglass shell, known as a "fairing", is placed over the frame on some models to shield the rider from the wind, aid in aerodynamics and protect engine components in an accident. Drag is the major factor that limits motorcycle speed. As evident in the streamlined appearance of new performance motorcycles, there is much aerodynamic technology included in the design. Since the 1958 FIM ban on motorcycle designs that cover the wheels or the rider, e.g., "dustbin" fairings, no major manufacturer has provided fairing to overcome the effect of the turbulence caused by the spinning front wheel, which prevents the motorcycle from cutting a clean path through the air. "Dustbin" fairings can improve aerodynamic performance without substantially compromising the rider's ability to control the machine, if the fairing is designed and tested for the effects of side winds.
Modern fairings on touring and sport-touring motorcycles dramatically improve a rider's comfort and attention on long rides by reducing the effect of the wind and rain on the body. They also help keep a rider warm in cold weather or high wind chill conditions, reducing hypothermia.
Also called windshields or screens, windscreens can be built into a fairing or be attached to an otherwise unfaired bike. They are usually made from transparent high-impact acrylic plastic. They may be shaped specifically to direct air flow over or around the head of the rider even if they are much shorter than the seated rider. Some motorcycles have electric screens, introduced on the 1986 BMW K100LT, which raise and lower the screen with the push of a button to the optimum height for conditions.
In the absence of a fairing or screen, a phenomenon known as the windsock effect occurs at speeds above 100 km/h (62 mph), where the rider becomes a major source of drag and is pushed back from the handlebars, tiring the rider. However, these motorcycles still effectively push their way through the atmosphere with brute force. A cabin cycle, which has a hull that wraps around the basic cycle frame, solved the problem of aerodynamics by isolating driver from outside air.
Saddlebags or panniers mount on either side of the rear wheel behind the saddle to carry parts, tools, and/or travel gear. They can be made of fibreglass, ABS, leather, Cordura, or other appropriate sturdy material. They are normally standard items on touring motorcycles but are usually optional on other types of motorcycles. They can be model-specific and available from a motorcycle's manufacturer, or after-market and designed to fit on numerous models.
Since motorcycles lack climate control or proper protection from the wind, some manufacturers offer heated seats or hand grips to relieve the discomfort of low temperatures experienced during night riding or the colder months. They can also be added on as after-market accessories and are powered by the bike's electrical system.
Luggage rack
A common addition to many bikes is an attachment onto which bags or other luggage can be fastened. This removes the need for rider backpacks and is generally a more secure and safe way to add carrying capacity to a motorcycle.
Sidecar

A sidecar is a one-wheeled device attached to the side of a motorcycle, producing a three-wheeled vehicle. Early sidecars were removable devices that could be detached from the motorcycle. Sidecars gradually superseded forecars and trailers. The forecar comprised a two-wheeled attachment at the front of the motorcycle. The trailer was just that, pulling the passenger along behind. In neither case could rider and passenger converse easily, and early sidecars were often called 'sociable' attachments.
Trailer hitch
A trailer hitch or tow hitch is a device mounted on a motorcycle that enables it to tow a motorcycle trailer, usually to haul additional gear.
Trunk
A motorcycle trunk is a storage compartment in the vicinity of the seat, other than panniers or saddlebags. A trunk mounted above and at the rear of the seat is called a top box.
Crash bar
Crash bars are less popular than they used to be - vulnerable engines and fairings now sometimes being protected by OE fitted snubs instead. A common arrangement is a loop of chrome-plated steel tube mounted each side of a motorcycle's lower frame. They primarily protect the bike's engine and body panels during slides or tipovers but can also serve as a mount point for accessories like highway pegs, lights and, on police motorcycles, sirens, cameras and radar guns. They give little protection to the rider and bigger ones were sometimes linked to injuries when feet became trapped. Less common variations include sump-guards, primarily for off-road riding.
Social aspects
Popularity
Recent years have seen an increase in the popularity of motorcycles. In the USA, registrations increased by 51% between 2000 and 2005. This is mainly attributed to increasing fuel prices and urban congestion, but is also partly due to television programmes such as reality show American Chopper or adventure-travel shows such as Long Way Down
Subcultures
Around the world, motorcycles have historically been associated with subcultures. Some of these subcultures have been loose-knit social groups such as the cafe racers of 1950s Britain, and the Mods and Rockers of the 1960s. A few are believed to be criminal gangs.
Social motorcyclist organisations are popular and are sometimes organised geographically, focus on individual makes, or even specific models. Example motorcycle clubs include: American Motorcyclist Association, Harley Owners Group, Moto Guzzi National Owners Club, Gold Wing Road Riders (GWRRA), and BMW MOA.
Many motorcycle organisations raise money for charities through organised events and rides. Some organisations hold large international motorcycle rallies in different parts of the world that are attended by many thousands of riders.
Some other motorcycle organisations exist only for the direct benefit of others. Bikers Against Child Abuse (BACA) is one example. BACA assigns members to individual children to help them through difficult situations, or even stay with the child if the child is alone or frightened.
In recent decades, motorcyclists have formed political lobbying organisations in order to influence legislators to introduce motorcycle-friendly legislation. One of the oldest such organisations, the British Motorcycle Action Group, was founded in 1973 specifically in response to helmet compulsion, introduced without public consultation. In addition, the British Motorcyclists Federation (BMF), originally founded in 1960 as a reaction to the public perception of motorcyclists as leather-jacketed hooligans, has itself moved into political lobbying.
Likewise, the U.S. has ABATE, which, like most such organisations, also works to improve motorcycle safety, as well as running the usual charity fund-raising events and rallies, often for motorcycle-related political interests.
Mobility
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. In places where it is permitted, lane splitting, also known as filtering, allows motorcycles to use the space between vehicles to move through stationary or slow traffic.
In the UK, motorcycles are exempt from the £8 per day London congestion charge other vehicles must pay to enter the city during the day. Motorcycles are also exempt from toll charges at some river crossings, such as the Severn Bridge, Dartford Crossing, and Mersey Tunnels. Some cities, such as Bristol, allow motorcycles to use bus lanes and provide dedicated free parking. In the United States, those states that have high-occupancy vehicle lanes also allow for motorcycle travel in them. Other countries have similar policies.
In New Zealand motorcycle riders are not required to pay for parking that is controlled by a barrier arm; the arm does not occupy the entire width of the lane, and the motorcyclist simply rides around it. Many car parks controlled in this way supply special areas for motorcycles to park, so as not to unnecessarily consume spaces.
In many 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."
Types
There are three major types of motorcycle: street, off-road, and dual purpose. Within these types, there are many different sub-types of motorcycles for many different purposes.
Street
Chpoers: Highly customised motorcycles based on a cruiser-style frame with long rake (longer front forks). They are also usually bare of various accessories and other non-essential parts. Many are created more for show than rideability.
Crusier: A range of small to large motorcycles designed for comfort and looks with a relaxed upright or reclined seating position. They often use lots of chrome and may be highly customised.
Electrical Motor Cycle: Nearly silent, zero-emission electric motor-driven vehicles. Operating range and top speed suffer because of limitations of battery technology. Fuel cells and petroleum-electric hybrids are also under development to extend the range and improve performance of the electric motors.
Mini bikes: Very small bikes designed to be simple run-around fun for both children and adults. Generally they have no hand-operated clutch or gearbox to simplify operation. Also known as Mini Motos. Not street-legal in most countries and jurisdictions. May be used for racing by all age levels.
Mopeds: Small, light, inexpensive, efficient rides for getting around town. Usually started by pedalling (motorcycle + pedals = moped). Mopeds typically have an engine mounted to the frame with a chain supplying the drive force to the wheel.
Naked bikes/Standard/Street bikes: Naked bikes have a riding position midway between the forward position of a sports bike and the reclined position of a cruiser. Unlike touring bikes, naked bikes often have little or no fairing (hence the title). Luggage capabilities are often an optional extra. Naked bikes are popular for commuting and other city riding because the upright riding position gives greater visibility in heavy traffic (both for the rider and to other road users) and are more comfortable than the hunched over sport bikes. Naked bike and standard are not fully interchangeable terms. Naked refers to the lack of bodywork, and standard refers to the upright riding position.
Scooters: Motorbikes with a step-through frame, generally smaller wheels than those of a traditional motorcycle and an engine mounted near the rear wheel on the swingarm. Can be ridden without straddling any part of the bike and usually features a floorboard. Available in sport, commuter, and touring models and wide variety of engine sizes from the standard 50 cc to 850 cc.
Sport bikes: Fast, light, sleek motorcycles designed to give maximum performance for racing or spirited road riding while conforming to FIM rules. They are distinguishable by their racing style fairings and the rider's tipped-forward seating position. They are also called "race replicas" because of their connection to the racing category for production motorcycles known as Superbike racing, and earlier similar race series (the term arose in the 1980s). The power to weight ratio of the 900 cc+ models typically matches or exceeds one bhp of power for every one kg of mass.
Racing bikes: Motorcycles designed for circuit or road racing, including mass-production motorcycles modified for motorcycle racing or sport riding.
Street customs: Highly customised motorcycles often with custom paint also built for show, but constructed from a sport bike frame instead of a cruiser-style frame.
Touring motorcycles: Touring bikes are designed for rider and passenger comfort, luggage carrying capacity, and reliability. Cruisers, sport bikes and some dual-sports can also be used as touring bikes with the addition of after-market luggage and sometimes seats. Common throughout the touring market are usually large-displacement fairings and windscreens (for weather and wind protection), large-capacity fuel tanks (for long-range travel), engines optimised for progressive torque rather than highest possible power, and a more relaxed, basically upright seating position.
Sport touring motorcycles: Sport-tourers combine attributes of a sport bike and a touring motorcycle. They are built for comfortable long-distance travel while maintaining a forward-leaning riding position, good handling, and high performance.
Underbones: Small motorcycle which is a crossover between a scooter and a true motorcycle with step-through frame, popular in Southeast Asia. While the fuel tank for most motorcycles are tear-shaped and located at the top and just behind the instrument panel, the fuel tank for an underbone motorcycle is located under the seat.
Off-road
Motocross bikes: Motorcycles designed for racing over closed circuits, often with jumps, over varied terrain of gravel/mud/sand. Sometimes simply called "dirt bikes" when not being raced, they can also be used for informal off-road recreation, or "mudding".
Supermoto: Beginning in the mid-1990s, motocross machines fitted with street wheels and tyres similar to those used on Sport bikes began to appear. These are known as "Supermotards", and riders of these machines compete in specially organised rallies and races.
Trials motorcycles: Motorcycles made as light as possible, with no seat (as they are designed to be ridden standing up), in order to provide maximum freedom of body positioning and stunt capability for use in observed trial competition.
Track racing machines or motorcycle dirt-track riding.
Dual-purpose
Dual-sport: Road-legal machines offering a compromise in highway and off-road performance, durability and comfort. Since the requirements are often conflicting, the manufacturer has to choose one or the other, resulting in a great variety of bikes in this category.
Enduro: Road-legal versions of a motocross machine, i.e., featuring high ground clearance and copious suspension with minimal creature comforts. Highly unsuitable for long distance road travel. The features that differ from the motocross versions are the silencers, the flywheel weights and the presence of features necessary for highway use.
Adventure Touring: Closely related to dual-sports, adventure tourers are motorcycles with lighter weight than just about any other bike considered a tourer, but heavier than any traditional dual-sport. Adventure tourers can handle with aplomb rough dirt paths such as fire roads however, for their weight they are generally not suited for anything more strenuous than that. The advantage is their increased number of luxury features and larger engines which make on-road riding much more enjoyable.
The motorcyclist's riding position depends on rider body-geometry (anthropometry) combined with the geometry of the motorcycle itself — falling along a spectrum of three basic postures.
Standard: In this position the rider sits roughly upright or leaning forwards slightly, knees lower than the hips, and feet roughly below the riders centre of gravity. The rider benefits from the freedom of head-movement and good visibility in all directions, along with easier use of the feet while, for instance, moving through stationary traffic. However, high speeds in this position leads to strain on the wrists, road uneveness leads to strain on the back, and extra exposure to the wind leads to both higher fuel consumption and a higher wind chill factor.
Sport: In this position the rider leans forward with the upper torso, supporting the upper-body weight with the back, stomach and leg muscles thereby keeping the forearms loose and relaxed providing smooth steering input/feedback at the handlebars. Knees are at hip height or below and squeezed against the tank to help support the upper body with the feet positioned on the balls of the foot on the footpegs. The position offers the advantage of decreased wind resistance but an otherwise cramped position that may be difficult to sustain for longer periods (some hours). The Sport riding position offers good flat-footing.
Cruiser: In this position the rider sits at a lower seat-height with the upper torso upright to slightly rearward. Knees are near hip height and legs extended forward. This position offers the advantage of comfortable circulation to the legs and ease of flat-footing—though with a lower field of visibility. In this position the rider may have difficulty lifting off the seat (when crossing an obstacle for example).
Important factors of a motorcycle's ergonomic geometry that determine the seating posture include the height, angle and location of footpegs, seat and handlebars. Likewise, factors in a rider's physical geometry that contribute to seating posture include torso, arm, thigh and leg length, and overall rider height.
Environmental impact
In 2007 and 2008, motorcycles and scooters, due to good fuel efficiency, attracted interest in the United States from environmentalists and those affected by increased fuel prices. Piaggio Group Americas supported this interest with the launch of a "Vespanomics" website and platform, citing lower per-mile carbon emissions (40 lb/mile less than the average car, a 65% reduction) and better fuel economy.
Other sources, however, point out that while motorcycles may be better in terms of greenhouse gases, a motorcycle releases 10–20 times more total pollution per mile than a new car. This pollution comes in large part from nitrogen oxide, a byproduct of combustion that is a major component of smog and is largely because of their less efficient catalytic converters.
United States Environmental Protection Agency 2007 certification result reports for all vehicles versus on highway motorcycles (which also includes scooters), the average certified emissions level for 12,327 vehicles tested was 0.734. The average "Nox+Co End-Of-Useful-Life-Emissions" for 3,863 motorcycles tested was 0.8531, for a difference of about 16%, not the claimed 10X factor. Likewise, if one looks at how many of the 2007 motorcycles tested were also catalytic equipped, 54% of them, 2,092, were equipped with a catalytic converter.
European emission standards for motorcycles are similar to those for cars. Motorcycles must meet Euro III standards, while cars must meet Euro IV standards. Therefore, the difference in total pollution between motorcycles and cars that pass European emission standards would be small, certainly much smaller than the 10X factor claimed by the referenced LA Times article