A light-framed vehicle possessing two wheels fitted with pneumatic tyres, the rear wheel being propelled by the rider through a crank, chain, and gear mechanism. The major uses to which bicycles are put are personal transport, particularly in underdeveloped countries, and sport. It is generally held that the modern pedal bicycle was invented by Kirkpatrick Macmillan of Dumfriesshire, Scotland, and first ridden by him in 1840. The pneumatic tyre was invented by Robert William Thomson in 1845 and first successfully applied to the bicycle in 1888 by John Boyd Dunlop.
For other uses, see velo binding.A bicycle, or bike, can be defined generally as a pedal-driven human-powered vehicle with two wheels attached to a frame, one behind the other. The International Union of Cycling adds the provision that the seat be more or less above the pedals, thus excluding recumbent bicycles.
First introduced in 19th-century Europe, bicycles now number over one billion worldwide, providing the principal means of transportation in many regions, notably China and the Netherlands.
The basic shape and configuration of the bicycle's frame, wheels, pedals, saddle, and handlebars have hardly changed since the first chain-driven model was developed around 1885 , although many important details have since been improved, especially since the advent of modern materials and computer-aided design.
The bicycle has affected history considerably, in both the cultural and industrial realms. In its early years, bicycle construction drew on pre-existing technologies; more recently, bicycle technology has, in turn, contributed ideas in both old and newer areas.
History
Several inventors and innovators contributed to the development of the bicycle. One of these, the scooter-like dandy horse of the French Comte de Sivrac, dating to 1790, was long cited as the earliest bicycle. Most bicycle historians now believe that these hobbyhorses with no steering mechanism probably never existed, but were made up by Louis Baudry de Saunier, a 19th-century French bicycle historian. However, the term hobbyhorse was later applied to the first documented ancestor of the modern bicycle, first introduced to the public in Paris by the German Baron Karl Drais in 1818..
The ancestor of the bicycle was first created by a German Baron, Karl Drais, who invented and patented his machine in 1817. So the first bicycle ride was from his residence town Mannheim to the suburb Rheinau.
Scottish blacksmith Kirkpatrick MacMillan refined this in 1839 by adding a mechanical crank drive to the rear wheel, thus creating the first true "bicycle" in the modern sense.
In the 1850s and 1860s, Frenchmen Ernest Michaux and Pierre Lallement took bicycle design in a different direction, placing the pedals on an enlarged front wheel. Lallement emigrated to the United States, where he recorded a patent on his bicycle in 1866 in New Haven, Connecticut. The primitive bicycles of this generation were difficult to ride, and the high seat and poor weight distribution made for dangerous falls.
The subsequent dwarf ordinary addressed some of these faults by adding gearing, reducing the front wheel diameter, and setting the seat further back, with no loss of speed. Starley's 1885 Rover is usually described as the first recognizably modern bicycle.
While the Starley design was much safer, the return to smaller wheels made for a bumpy ride. By the turn of the century, bicycling clubs flourished on both sides of the Atlantic, and touring and racing were soon extremely popular.
Successful early bicycle manufacturers included Englishman Frank Bowden and German builder Ignaz Schwinn. Bowden started the Raleigh company in Nottingham in the 1890s, and was soon producing some 30,000 bicycles a year. Schwinn bicycles soon featured widened tires and spring-cushioned, padded seats, sacrificing a certain amount of efficiency for increased comfort. Facilitated by connections between European nations and their overseas colonies, European-style bicycles were soon available worldwide. By the mid-20th century, bicycles had become the primary means of transportation for millions of people around the globe.
In many western countries, the use of bicycles levelled off or declined as motorized transportation became affordable and car-centred policies led to an increasingly hostile environment for bicycles. In North America, bicycle sales declined markedly after 1905, to the point where, by the 1940s, they had largely been relegated to the role of children's toys. However, in other parts of the world, such as China, India, and European countries such as Germany, Denmark, and the Netherlands, the traditional utility bicycle remained a mainstay of transportation; In the early 1980s, Swedish company Itera invented a new type of bicycle, called the Itera plastic bicycle, made entirely out of plastics. The plastic bicycle was however a commercial failure.
In North America, increasing consciousness of physical fitness and environmental preservation spawned a renaissance of bicycling in the late 1960s. Bicycle sales in the US boomed, largely in the form of the racing bicycles, long used in such events as the hugely popular Tour de France. By the 1980s, these newer designs had driven the three-speed bicycle from the roads. Manufacturers responded with the hybrid bicycle, which restored many of the features long enjoyed by riders of the time-tested European utility bikes.
Technical aspects
Legal requirements
The 1968 Vienna Convention on Road Traffic considers a bicycle to be a vehicle, and a person controlling a bicycle is considered a driver. The traffic codes of many countries reflect these definitions and demand that a bicycle satisfy certain legal requirements, sometimes even including licensing, before it can be used on public roads. In many jurisdictions it is an offense to use a bicycle that is not in roadworthy condition. In most places, bicycles must have functioning front and rear lights or lamps when ridden after dark. Since a moving bicycle makes very little noise, in many countries bicycles must have a warning bell for use when approaching pedestrians, equestrians and other bicyclists.
Construction and parts
Frame
Nearly all modern upright bicycles feature the diamond frame, a truss, consisting of two triangles: the front triangle and the rear triangle.
Historically, women's bicycle frames had a top tube that connected in the middle of the seat tube instead of the top, resulting in a lower standover height at the expense of compromised structural integrity, since this places a strong bending load in the seat tube, and bicycle frame members are typically weak in bending. While some women's bicycles continue to use this frame style, there is also a hybrid form, the mixte or step-through frame, which splits the top tube into two small top tubes that bypass the seat tube and connect to the rear dropouts. Unfortunately for the old tall man, because of its persistent image as a "women's" bicycle, the vast majority of mixte frames are quite small.
Historically, materials used in bicycles have followed a similar pattern as in aircraft, the goal being strength and low weight.
Drivetrain
The drivetrain begins with pedals which rotate the cranks, which fit into the bottom bracket.
Since cyclists' legs produce a limited amount of power most efficiently over a narrow range of cadences, a variable gear ratio is needed to maintain an optimum pedaling speed while covering varied terrain.
Internal hub gearing works by planetary, or epicyclic, gearing, in which the outer case of the hub gear unit turns at a different speed relative to the rear axle depending on which gear is selected.Internal hub gears are immune to adverse weather conditions that affect derailleurs, and often last longer and require less maintenance.
Road bicycles have close set multi-step gearing, which allows very fine control of cadence, while utility cycles offer fewer, more widely spaced speeds.
Fixed-gear track racing bikes can achieve transmission efficiencies of over 99% (nearly all the energy put in at the pedals ends up at the wheel).
There have been, and still are, drivetrains that are quite different from these:
Retro-Direct drivetrains used on some early 20th century bicycles have been resurrected by bicycle hobbyists. Other bicycles of that era dispensed with the chain entirely and used an enclosed driveshaft and bevel gears. These shaft-driven bicycle were strongly built but were not mechanically efficient.Steering and seating
The handlebars turn the fork and the front wheel via the stem, which articulates with the headset.
Variations on these styles exist. Bullhorn style handlebars are often seen on modern time trial bicycles, equipped with two forward-facing extensions, allowing a rider to rest the entire forearm on the bar.
Saddles also vary with rider preference, from the cushioned ones favoured by short-distance riders to narrower saddles which allow more free leg swings. With comfort bikes and hybrids the cyclist sits high over the seat, their weight directed down onto the saddle, such that a wider and more cushioned saddle is preferable.
A recumbent bicycle has a reclined chair-like seat that is more comfortable than a saddle, especially for riders who suffer from certain types of back pain.
Brakes
Modern bicycle brakes are either rim brakes, in which friction pads are compressed against the wheel rims, internal hub brakes, in which the friction pads are contained within the wheel hubs, or disc brakes. In the late 1990s, disc brakes appeared on some off-road bicycles, tandems and recumbent bicycles, but are considered impractical on road bicycles, which rarely encounter conditions where the advantages of discs are significant.
The advantages of discs make them well-suited to steep, extended downhills through wet and muddy off-road terrain, which falls under the category of downhill and freeride bicycle riding.
Two main disc brake systems exist: hydraulic and mechanical (cable-actuated). Mechanical disc brakes have less modulation than hydraulic disc brake systems, and since the cable is usually open to the outside, mechanical disc brakes tend to pick up small bits of dirt and grit in the cable lines when ridden in harsh terrain. However, since hydraulic disc brakes usually require relatively specialized tools to bleed the brake systems, repairs on the trail are difficult to perform, whereas mechanical disc brakes rarely fail.
For track cycling, track bicycles do not have brakes. Most track bike frames and forks do not have holes for mounting brakes, although with their increasing popularity among some road cyclists, some manufacturers have drilled their track frames to enable the fitting of brakes. Track rider are still able to slow down because all track bicycles are fixed, meaning that there is no freewheel. Cyclists who ride a track bike without brake(s) on the road can also slow down by skidding, by unweighting the rear wheel and applying a backwards force to the pedals, causing the rear wheel to lock up and slide along the road.
Accessories and Repairs
Some components, which are often optional accessories on sports bicycles, are standard features on utility bicycles to enhance their usefulness and comfort.
Toe-clips and toestraps, or clipless pedals, help to keep the foot planted firmly on the pedals, and enable the cyclist to pull as well as push the pedals. A bicycle helmet is classified by some as an accessory, but as an item of clothing by others.
Many cyclists carry tool kits, containing at least a tire patch kit (and/or a spare tube), tire levers, and allen wrenches. Some bicycle parts, particularly hub-based gearing systems, are complex, and many prefer to leave maintenance and repairs to professionals. Others maintain their own bicycles, enhancing their enjoyment of the hobby of cycling.
Performance
In both biological and mechanical terms, the bicycle is extraordinarily efficient. In terms of the ratio of cargo weight a bicycle can carry to total weight, it is also a most efficient means of cargo transportation.
A human being travelling on a bicycle at low to medium speeds of around 10-15 mph (16-24 km/h), using only the energy required to walk, is the most energy-efficient means of transport generally available. A bicycle which places the rider in a seated position, supine position or, more rarely, prone position, and which may be covered in an aerodynamic fairing to achieve very low air drag, is referred to as a recumbent bicycle or human powered vehicle. Humans create the greatest amount of drag on an upright bicycle at about 75% of the total drag.
Dynamics
A bicycle stays upright by being steered so as to keep its center of gravity over its wheels. This steering is usually provided by the rider, but under certain conditions may be provided by the bicycle itself.
A bicycle must lean in order to turn. This lean is induced by a method known as countersteering, which can be performed by the rider turning the handlebars directly with the hands or indirectly by leaning the bicycle.
Short-wheelbase or tall bicycles, when braking, can generate enough stopping force at the front wheel in order to flip longitudinally.
Further reading
For more information on the technical aspects of bicycles, see also:
List of bicycle parts and Category:Bicycle partsSocial and historical aspects
Economic implications
Bicycle manufacturing proved to be a training ground for other industries and led to the development of advanced metalworking techniques, both for the frames themselves and for special components such as ball bearings, washers, and sprockets. The Morris Motor Company (in Oxford) and Škoda also began in the bicycle business, as did Henry Ford and the Wright Brothers.
Some bicycle clubs and national associations became prominent advocates for improvements to roads and highways. Both their model for political organization and the paved roads for which they argued facilitated the growth of the bicycle's rival, the automobile.
Until recently cycle manufacturers in the west generally built their own frames and used components made by other companies to assemble a complete cycle, although very large companies such as Raleigh used to make almost every part of a bicycles including eg bottom bracket axles etc. In recent years, US and European bicycle makers have changed their methods of production. Many companies now only assemble, every part of the bicycle including the frame will have been made by other companies. Some sixty percent of the world's bicycles are now being made in China. Despite this shift in production, as nations such as China and India become more wealthy, their own use of bicycles has declined due to the increasing affordability of cars and motorcycles. One of the major reasons for the proliferation of Chinese-made bicycles in foreign markets is the lower cost of labour in China.
Female emancipation
The diamond-frame safety bicycle gave women unprecedented mobility, contributing to their emancipation in Western nations. As bicycles became safer and cheaper, more women had access to the personal freedom they embodied, and so the bicycle came to symbolise the New Woman of the late nineteenth century, especially in Britain and the United States.
The bicycle was recognised by nineteenth-century feminists and suffragists as a "freedom machine" for women. Anthony said in a New York World interview on February 2, 1896: "Let me tell you what I think of bicycling. In 1895 Frances Willard, the tightly-laced president of the Women’s Christian Temperance Union, wrote a book called How I Learned to Ride the Bicycle, in which she praised the bicycle she learned to ride late in life, and which she named "Gladys", for its "gladdening effect" on her health and political optimism.
The male anger at the freedom symbolised by the New (bicycling) Woman was demonstrated when the male undergraduates of Cambridge University chose to show their opposition to the admission of women as full members of the university by hanging a woman in effigy in the main town square -- tellingly, a woman on a bicycle.
In the 1890s the bicycle craze led to a movement for so-called rational dress, which helped liberate women from corsets and ankle-length skirts and other restrictive garments, substituting the then-shocking bloomers.
Other social implications
Sociologists suggest that bicycles enlarged the gene pool for rural workers, by enabling them to easily reach the next town and increase their courting radius. In cities, bicycles helped reduce crowding in inner-city tenements by allowing workers to commute from more spacious dwellings in the suburbs. Bicycles allowed people to travel for leisure into the country, since bicycles were three times as energy efficient as walking, and three to four times as fast.
Cycling and public health
The physical exercise gained from cycling is generally linked with increased health and wellbeing.
Cycling is not generally considered as a high-risk activity .
A Danish study in 2000 concluded that cycling to work was linked to a 40% reduction in mortality rate;
Uses for bicycles
Bicycles at work
The postal services of many countries have long relied on bicycles. The British Royal Mail first started using bicycles in 1880; now bicycle delivery fleets include 37,000 in the UK, 25,700 in Germany, 10,500 in Hungary and 7000 in Sweden. The London Ambulance Service has recently introduced bicycling paramedics, who can often get to the scene of an incident in Central London more quickly than a motorised ambulance.
Police officers adopted the bicycle as well, initially using their own. The Kent police purchased 20 bicycles in 1896, and by 1904 there were 129 police bicycle patrols operating. Some countries retained the police bicycle while others dispensed with them for a time. Bicycle patrols are now enjoying a resurgence in many cities, as the mobility of car-borne officers is becoming increasingly limited by traffic congestion and pedestrianisation. The pursuit of suspects can also be assisted by a bicycle.
Bicycles enjoy substantial use as general delivery vehicles in many countries. In the UK and North America, generations of teenagers have got their first jobs delivering newspapers by bicycle. London has many delivery companies that use bicycles with trailers. In India, many of Mumbai's Dabbawalas use bicycles to deliver hot lunches to the city’s workers. In Bogotá, Colombia the city’s largest bakery recently replaced most of its delivery trucks with bicycles. Even the car industry uses bicycles. At the huge Mercedes-Benz factory in Sindelfingen, Germany workers use bicycles, colour-coded by department, to move around the factory.
Bicycle recreation
Bicycles are used for recreation at all ages. Bicycle touring, also known as cyclotourism, involves touring and exploration or sightseeing by bicycle for leisure.
One aspect of Dutch popular culture is enjoying relaxed cycling in the countryside of the Netherlands. The land is very flat and full of public bicycle trails where cyclist aren't bothered by cars and other traffic, which makes it ideal for cycling recreation. Paris-Brest-Paris (PBP), which began in 1891, is the oldest bicycling event still run on a regular basis on the open road, covers over 1200 km and imposes a 90-hour time limit.
Bicycles and war
The bicycle is not suited for combat, but it has been used as a method of transporting soldiers and supplies to combat zones. Bicycles were used in the Second Boer War, where both sides used them for scouting. In World War I, France and Germany used bicycles to move troops. In its 1937 invasion of China, Japan employed some 50,000 bicycle troops, and similar forces were instrumental in Japan's march through Malaysia in World War II. Germany used bicycles again in World War II, while the British employed airborne Cycle-commandos with folding bikes.
In the Vietnam War, communist forces used bicycles extensively as cargo carriers along the Ho Chi Minh Trail. There are reports of mountain bicycles being used in scouting by U.S. Special Forces in the U.S. invasion of Afghanistan and in subsequent battles against the Taliban. British troops, designated Light Bicycle Infantry LBI were recently, as of 06 January 2005, using bicycles to patrol in Basra, Iraq.
The only country to recently maintain a regiment of bicycle troops was Switzerland, who disbanded the last unit in 2003.
Bicycle racing
Shortly after the introduction of bicycles, competitions developed independently in many parts of the world. Early races involving boneshaker style bicycles were predictably fraught with injuries. Large races became popular during the 1890's "Golden Age of Cycling", with events across Europe, and in the U.S. and Japan as well. The most famous of all bicycle races is the Tour de France.
As the bicycle evolved its various forms, different racing formats developed. They range from the one-day road race, criterium, and time trial to multi-stage events like the Tour de France and its sister events which make up cycling's Grand Tours. Recumbent bicycles were banned from bike races in 1934 after Marcel Berthet set a new hour record in his Velodyne streamliner (49.992 km on Nov 18, 1933). Track bicycles are used for track racing in Velodromes , while cyclo-cross races are held on rugged outdoor terrain.
The governing body of international cycle sport, the Union Cycliste Internationale, decided in the late 1990s to create additional rules restricting the design of racing bicycles. These rules met with considerable controversy and to some extent arrested the development of the racing bicycle.
Modal share: cycle use in modern cities
Cyclists and motorists make different demands on road design which may lead to conflicts both in politics and on the streets. In Shanghai, a city where bicycles were once the dominant mode of transportation, bicycle travel on city roads was actually banned temporarily in December 2003.
In areas in which cycling is popular and encouraged, cycle-parking facilities using bicycle racks, lockable mini-garages, and patrolled cycle parks are used to reduce theft. Local governments also promote cycling by permitting the carriage of bicycles on public transport or by providing external attachment devices on public transport vehicles.
Extensive bicycle path systems may be found in some cities. Segregating bicycle and automobile traffic in cities has met with mixed success, both in terms of safety and bicycle promotion.
Cycling activism
Cyclists form associations, both for specific interests (trails development, road maintenance, urban design, racing clubs, touring clubs, etc.) and for more global goals (energy conservation, pollution reduction, promotion of fitness). Two broad themes run in bicycle activism: one more overtly political with roots in the environmental movement; the other drawing on the traditions of the established bicycle lobby.
Such groups promote the bicycle as an alternative mode of transport and emphasize the potential for energy and resource conservation and health benefits gained from cycling versus automobile use. Many cities also have community bicycle programs that promote cycling, especially as a means of inner-city transport.
Controversially, some bicycle activists (including some traffic management advisors) seek the construction of segregated cycle facilities for journeys of all lengths.
Critical Mass is a worldwide activist movement of mass bicycle protest rides. It incorporates the themes of increasing the road- and mind-share given to bicycle transport, and has drawn support from environmentally minded campaigners and other schools of political thought.
Midnight Ridazz is an massive established bicycle ride in Los Angeles based on recreational activism.
There is a long-running cycle helmet debate among activists.
Types of bicycle
Bicycles can be categorized in different ways: e.g. Mountain bicycles are designed for off-road cycling, and include other sub-types of off-road bicycles such as Cross Country (i.e."XC"), Downhill , and to a lesser extent Freeride bicycles. All mountain bicycles feature sturdy, highly durable frames and wheels, wide-gauge treaded tires, and cross-wise handlebars to help the rider resist sudden jolts. Some mountain bicycles feature various types of suspension systems (e.g. Mountain bicycle gearing is very wide-ranging, from very low ratios to high ratios, typically with 21 to 30 gears. Racing bicycles are designed for speed, and include road, time trial, and track bicycles. Racing bicycles have a relatively narrow gear range, and typically varies from medium to very high ratios, distributed across 18, 20, 27 or 30 gears. The more closely spaced gear ratios allow racers to choose a gear which will enable them to ride at their optimum pedaling cadence for maximum efficiency. Touring bicycles are designed for bicycle touring and long journeys. unicycles are not proper bicycles, as they have only one wheel.
Standards
A number of formal and industry standards exist for bicycle components, to help make spare parts exchangeable:
ISO 5775 Bicycle tire and rim designations ISO 8090 Cycles — Terminology (same as BS 6102-4) ISO 4210 Cycles — Safety requirements for bicycles
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