Bicycle

"Bicycle" may also refer to Bicycle Playing Cards.

A bicycle, or bike, is a pedal-driven land vehicle with two wheels arranged in line. First introduced in 19th century Europe, it evolved quickly into its current basic design. The bicycle still enjoys widespread use. With over one billion in the world today, bicycles provide the principal means of transportation in many regions and a popular form of recreation in others. Bicycling has been the focus of increased popularly in recent years; its derivatives of bicycle racing and mountain biking are now popular in many parts of the world.

Main article: History of the bicycle

No specific time or person can be identified with the invention of the bicycle. Its earliest known forebears were called velocipedes, and included the scooter-like dandy horses of the French Comte de Sivrac, dating to 1790, and German tax collector Karl von Drais, who rode his 1816 machine on his rounds. A Scottish blacksmith, Kirkpatrick MacMillan, is credited with adding a treadle drive mechanism in 1840, for the first time enabling the rider to lift his feet off the ground. In the 1850s and 1860s, Frenchman Ernest Michaux and his pupil Pierre Lalloment placed pedals on a greatly enlarged front wheel. Their creation, aptly called the Boneshaker, featured a heavy steel frame on which were mounted wooden wheels with iron tires.

While the Boneshaker met the modern definition of a bicycle, it was in England that the bicycle took on its current form. In the 1870s, Coventry's James Starley mounted the seat more squarely over the pedals, so that the rider could push them more forcefully. This first practical bicycle was called the Ordinary, and was introduced to the United States, where the Columbia version became the first popular American cycle. British cyclists likened the disparity in size of the two wheels to their coinage, nicknaming this vehicle the "penny-farthing". It was Starley's nephew, John Kent Starley, who subsequently gave the bicycle its current form, in 1886. In the Ordinaries, pedals directly drove the front wheel, and enlarging the latter had been the only way to increase speed. J. K. Starley introduced a chain to provide rear wheel drive, mounted the wheels and seat on a stable two-triangle frame, and dramatically reduced the size of the front wheel. His diamond-frame safety bike, so named since the rider no longer needed to fear being tossed over a six-foot-high front end, looked remarkably like the bicycles seen today on European and Asian streets.

While the Starley frame was much safer, the return to a smaller front wheel made for a bumpy ride. Three subsequent innovations added increased comfort and ushered in the 1890s Golden Age of Bicycles. In 1888 Scotsman John Boyd Dunlop introduced the pneumatic tire, which soon became universal. Shortly thereafter the rear freewheel was developed, enabling the rider to coast without the pedals spinning out of control. This refinement led to the 1898 invention of coaster brakes. Derailleur gears and hand-powered, cable-pull brakes were also developed during these years, but were slow to be adopted by casual riders. By the turn of the century, bicycling clubs flourished on both sides of the Atlantic, and touring and racing were soon the rage.

Successful early bicycle manufacturers included Englishman Frank Bowden and German builder Ignaz Schwinn. Bowden started the Raleigh company in Nottingham in the 1890s, and soon was producing some 30,000 bicycles a year. Schwinn emigrated to the United States, where he founded a similarly successful company in Chicago in 1895. Schwinn bicycles soon featured widened tires and spring-cushioned padded seats, sacrificing some efficiency for increased comfort. Facilitated by connections between European nations and their overseas colonies, European-style bicycles were soon available worldwide. In time, familiarity with and use of bicycles filtered down from the upper to the less advantaged classes in Asian and African nations, and by the mid-20th century these bicycles had become the primary means of transportation for millions of people around the globe.

The popularity of bicycles leveled off or declined as people turned to motorcars as these became more affordable. 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. In other parts of the world, such as China, India, and European countries such as the Netherlands, Germany, and Denmark, bicycles remained a mainstay of transportation, their design little altered except for the increasing popularity of hand brakes and the internal hub gears which allowed greater distances and more varied terrain to be covered.

In North America, increasing consciousness of physical fitness and environmental preservation spawned a renaissance of bicycling in the late 1960s. Bicycle sales in the United States boomed, largely in the form of the racing bicycles long used in such events as the hugely popular Tour de France. First these cycles, and then the mountain bikes which followed, virtually eliminated the practical three-speed bicycle from American roads. In response however to consumer dissatisfaction with bicycles made for more targeted audiences, many American recreational cyclists demanded a more practical product. Manufacturers responded with the hybrid bicycle, which offered a more comfortable ride, but still lacked the accessories found on the bicycles long favored by the less style-conscious European cyclists. Meanwhile, designers of these so-called utility bicycles continued to improve their own product, including upgrading the internal hub gearing options to offer upwards of ten speeds.

Under the terms of the Vienna convention on Road Traffic, a bicycle is considered to be a vehicle and a person controlling a bicycle is considered to be a driver. The traffic codes of many countries reflect these definitions. As with other vehicles, there are usually legally defined requirements that a bicycle must satisfy before it can be lawfully used on public roads. In many jurisdictions it is an offence to use a bicycle that is not in roadworthy condition and which does not have functioning front and rear brakes. Another widespread legal requirement is that bicycles should have functioning front and rear lights or "lamps". As some generator or "dynamo" driven bicycle lamps only operate while moving, the use of an additional rear reflector is frequently also mandatory. Since a moving bicycle makes very little noise, in many countries bicycles are also required to be fitted with a warning bell for use when approaching pedestrians, equestrians and other bicyclists.

Main article: Bicycle frame construction

Modern bicycles retain the same diamond frame design, incorporating a pair of contiguous triangles, introduced a century ago. The front wheel attaches to the fork, which in turn links via bearings to the head set on the front of the frame. The handle bars attach atop the headset via a stem. Some mountain bicycles substitute a fork-like system on the rear as well, adding suspension systems for a smooth ride over rough ground. The pedals rotate cranks which fit into the bottom bracket. Attached to the crank is the chainring which drives the chain, which in turn rotates the rear wheel. Within this drive train may be interspersed various gearing systems, described below, which vary the number of rear wheel revolutions produced by each turn of the pedals.

Since cyclists' legs work best at specific speeds, or cadences, varied gear ratios allow one to maintain an optimum pedaling speed while covering varied terrain. Road bicycles have close set gearing, which allows very fine control of cadence, while three-speed or utility cycles offer a lesser number of more widely spaced "speeds". Mountain bikes may offer an extremely low gear to facilitate climbing slowly on steep hills. The gear systems are hand-operated, via cables, and are of two types. Internal hub gearing still predominates with casual cyclists except in North America, where external derailleur systems are far more common. Derailleurs, which can be placed on both the front chainring and on the rear cluster or cassette, apply strain on the chain by pushing it to either side. The sides of the gear rings "catch" the chain when it is pushed against them, pulling it up onto their teeth to change gears.

Three handlebar styles are common. Touring handlebars, the norm in Europe and elsewhere until the 1970s, curve gently back toward the rider, offering a natural grip and comfortable upright position. Racing handlebars are "dropped", offering the cyclist either an aerodynamic "hunched" position or a more upright posture in which the hands grip the brake lever mounts. Mountain bikes feature a crosswise handlebar which helps prevent the rider from pitching over the front in case of sudden deceleration. Seats also vary depending on rider preference, from the cushioned saddles favored by short-distance riders to narrower seats which allow more free leg swings.

Bicycle brakes are either rim brakes, in which rubber pads are compressed against the wheel rims, or hub brakes, which are contained within the wheel hubs. Hub brakes may be either hand-driven or pedal-driven, as in the coaster brakes which were the rule in North America until the 1960s. Rim brakes on European bicycles are often powered by a system of rods and levers, while lightweight touring bicycles and nearly all North American bikes have cable-pull designs. These feature paired, padded calipers which are squeezed together onto the wheel rims by a cable pulled by the brake handles. The larger tires on mountain bicycles presented a braking problem, since they did not accommodate the usual calipers. This was first solved with a cantilever system using two "half calipers", and then with the safer, more powerful, and better-centered v-brake. In the late 1990s, disc brakes appeared on some off-road bicycles and on tandems, but are considered impractical on road bicycles, where the additional stopping power and higher weight are less desirable.

Most utility bicycles also have features intended enhance their usefulness and increase the comfort of the everyday user. Examples include the use of "chainguards" and "mudguards" or "fenders"(US) to protect clothes from oil and spray. Front mounted wicker or steel baskets for holding shopping and other goods are often used. There will usually be a rear rack or carrier that can be used to carry items such as school satchels. Parents with small children may have rear mounted child seats and/or an auxiliary saddle fitted to the crossbar so that they can transport their children to school or other destinations. Utility or town bikes frequently also have an integral kick stand for parking.

Materials used in bicycles are similar to those in aircraft, the goal being a strong and lightweight frame. Before the 1970s, hollowed tubes of steel and then chromaloy, a chrome-steel, predominated. In the 1980s aluminum became popular, and its affordability makes it still common. More expensive carbon fibre and titanium frames are now available. Each material has advantages and disadvantages: materials differ in durability, aesthetics, reparability, and weight.

In both biological and mechanical terms, the bicycle is extraordinarily efficient. In terms of the number of calories of energy a person must expend to travel a given distance, S.S.Wilson calculated it to be the most efficient self-powered means of transportation¹. From a mechanical viewpoint, engineers studying the efficiency of the chain drive mechanism have also determined that more than 98% of the energy delivered by the rider into the pedals is transmitted to the wheels, with less than 2% sacrificed to friction and heat loss². 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.

Typical speeds for bicycles are 16 to 32 km/h (10 to 20 mph). On a fast racing bicycle, a reasonably fit rider can ride at 50 km/h (30 mph) on flat ground for short periods. The highest speed ever attained on the flat, without riding behind a wind-block, is by Canadian Sam Whittingham, who in 2001 set a 142.51 km/h (80.55 mph) record on his highly aerodynamic recumbent bicycle. This stands as the record for all human-powered vehicles. (Faster speeds can be achieved if air resistance is reduced by motor pacing.)

Accessories for both bicycles and cyclists are numerous. More technical examples include speedometers and odometers for measuring distance. Air or battery powered horns and additional reflectors may also be fitted. Some accessories are for the bicycle user, an example being the humble "bicycle clip", used for restraining trouser legs and keeping them away from the frame. Many bicycle users also use additional reflective belts or vests at night. Specialised cycling clothes such as padded shorts are used by sports cyclists and long-distance cycle-tourists. The use of some accessories shows a strong cultural bias. For instance in North America, a large minority of adult bicycle users wear plastic bicycle helmets. By contrast in most European countries, helmets are viewed as an indicator of "inexperience" or "recklessness". Consequently their use is confined primarily to small children or sports cyclists and their use is considered unusual and even inappropriate among adult utility cyclists.

Many cyclists also carry tool kits, containing at least a patch kit for tires and some wrenches. At one time it was possible to use a single multiple spanner tool to carry out most common bicycle repairs. Increasingly however the trend has been towards more specialised parts requiring more complex tools up to and including proprietary tools specific for a given manufacturer. Some bicycle parts are complex, particularly hub-based gearing, systems and many people prefer to leave all but small repairs and maintenance to professionals. Others prefer to maintain their own bicycles finding it enhances their enjoyment of the hobby of cycling.

For more information on the technical aspects of bicycles, see also:

• Bicycle frame construction
• List of bicycle parts
• Bicycle brake systems
• Bicycle lighting

Bicycle manufacturing proved from the outset to be a training ground for other industries. Building modern bicycle frames led to the development of advanced metalworking techniques, both for the frames themselves and for special components such as ball bearings, washers, and sprockets. These techniques later enabled skilled metalworkers and mechanics to develop the components used in early automobiles and aircraft. England's William Richard Morris, as well as Henry Ford and the Wright Brothers all got their start as bicycle mechanics.

The evolution of the bicycle had less tangible effects as well, extending early to areas as diverse as fashion and politics. In the 1890s the cycling craze led to a new set of fashions, including bloomers, which helped liberate women from corsets and other restrictive clothing. A British perfumer marketed Cycling Bouquet, which came in a tiny vial designed to fit into a purse small enough for a lady cyclist to carry. The diamond-frame safety bicycle gave women unprecedented mobility, contributing to their emancipation in Western nations. 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 single-family dwellings in the suburbs. They also reduced dependence on horses, and allowed people to travel into the country, since bicycles were three times as energy efficient as walking, and three to four times as fast. In North America, the political organization of bicycle enthusiasts, in such groups as the League of American Wheelmen, led to further changes. Both their model for political organization and the paved roads for which they argued facilitated the growth of the bicycle's rival, the automobile.

In recent years, bicycles are one of many manufactures whose production has largely moved to Asia. 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, bicycling there is becoming less popular. One of the major reasons for the proliferation of Chinese-made bicycles in foreign markets is the increasing preference of its own citizens for cars and motorcycles³.

The bicycle is not suited for combat. Unlike the horse, it can sustain neither the swing of a sword nor the recoil of a gun. It has been used though for "mounted infantry", troops that use the bicycle for transport and then dismount before fighting. Late in the 19th century, the United States Army tested the bicycle's suitability for cross-country troop transport. "Buffalo soldiers" stationed in Montana rode bicycles across roadless landscapes for hundreds of miles with impressive speed.

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In 20th century wars, armies used bicycles for logistical support. In the Boer War, both sides used them for scouting. In World War I, France and Germany used bicycles as a supplementary way to move troops. In World War II, Germany used them to supplement mechanized transport. In the invasion of Poland, German forces relied on bicycles and horses for follow-up support needed to sustain the blitzkrieg. Later in the war, as German logistics broke down, some ad hoc units used confiscated bicycles in their retreat from the Netherlands.

In its 1937 invasion of China, Japan employed some 50,000 bicycle troops. Early in the Second World War their southern campaign through Malaya en route to capturing Singapore in 1941 was largely dependent on bicycle-riding soldiers. In both efforts bicycles allowed quiet and flexible transport of thousands of troops who were then able to surprise and confuse defenders. Bicycles also made few demands on the Japanese war machine, needing neither trucks, nor ships to transport them, nor precious petroleum. Allied use of the bicycle in World War II was limited, but included supplying folding bicycles to paratroopers and to messengers behind friendly lines. The successful British siege of a German radar installation at Ste. Bruneval, France in 1942 was conducted by airborne Cycle-commandos with the aid of these folding bikes.

In the Vietnam War, communist forces used bicycles extensively as cargo carriers along the Ho Chi Minh Trail. Heavily loaded with supplies, these bicycles were seldom rideable. Instead a tender would walk alongside, pushing the bike like a wheelbarrow. With especially bulky cargo, tenders sometimes attached bamboo poles to the bike for tiller-like steering. There are some reports of the use of mountain bicycles by U.S. Special Forces as a scouting vehicle in the U.S. invasion of Afghanistan and in subsequent battles against the Taliban. The only country to recently maintain a division of bicycle troops was Switzerland. They eliminated the last remaining division a few years ago.

Urban bicycle transportation and automobile transportation seem to be mutually antagonistic. The growth of one is associated with a decline of the other. Cyclists and drivers make different demands on urban design, and since urban space and resources are limited, conflict occurs -- both in politics and on the streets.

Bicycles share the roads freely with cars in such bicycle-friendly cities as Amsterdam and Copenhagen, while elsewhere in Europe and North America they often coexist in an uneasy truce. At other times, the pendulum swings to an extreme. 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.

Bicycle paths are often found in cities with an auto-free zone, or with vast park systems, but even such dedicated paths often have to be shared with inline skaters, scooters, skateboard enthusiasts and wayward pedestrians. Bicycle engineer John Forester is one of many skeptics concerning the roots of these apparently bicycle-friendly developments⁴. He argues that road bikes belong on the street, and that construction of segregated cycle facilities such as cycle paths, or multi-use trails (MUTs), is often a veiled attempt to force bicycles off the roads.

Millions of people use bikes for short-range transportation, particularly in densely populated cities, where slow vehicle traffic, high registration and parking costs, and environmental concerns make commuting by automobile less attractive. While in many European and Asian countries bicycles have long been the preferred means of urban commuting, American cyclists have had to fight for space on busy city streets, a process which has been accelerated with gentrification of urban and semi-urban areas. In response to bicycle activists, many jurisdictions now provide cyclist-only lanes on roads, as well as bicycle trails, for both commuting and recreational cyclists. Local governments have also helped to facilitate the local use of bicycles by providing attachment devices on buses, trains, and subway cars. To reduce theft, many destinations also provide bicycle racks or lockable mini-garages.

"Critical Mass" is a worldwide phenomenon of mass bicycle protest rides. Non-hierarchical, with an emphatic lack of formal organization, its participants ride in a highly visible manner to point out and protest the problems of automobile-dominated culture. Critical Mass rides began in 1992 in San Francisco and quickly spread around the world.

Bicycle advocacy groups exist in many cities, providing information for cyclists and lobbying the government to consider the benefits of cycle commuting and the needs of cyclists when planning transportation infrastructure.

By number of riders:

• A tandem or twin has two riders.
• A triplet has three riders; a quadruplet has four.
• The largest multi-bike had 40 riders.

By general construction:

• A penny-farthing or ordinary has one high wheel directly driven by the pedals and one small wheel.
• On an upright bicycle the rider sits astride the saddle.
• On a recumbent bicycle the rider reclines or lies supine.
• A Pedersen bicycle has a bridge truss frame.
• A folding bicycle can be quickly folded for easy carrying, for example on public transport.
• An exercise bicycle doesn't go anywhere at all.

By gearing:

• Internal hub gearing is still most common in European bicycles, usually ranging from three-speed bicycles to five and seven speed options.
• Most racing and touring bicycles have derailleur gears, offering from 5 to 27 speeds
• Fixed gear bicycles have only one gear and no freewheel mechanism, so whenever the bike is in motion the pedals continue to spin. These bikes are mainly used in track cycling or by bicycle messengers
• Single speed bicycles have only one gear and have a freewheel mechanism.
• Shaft drive bicycles connect the pedals to the rear hub with a shaft instead of a chain.

By location or sport:

• Racing bicycles have lightweight frames with minimal accessories, dropped handlebars to allow for an aerodynamic riding position, and derailleur gears offering a wide variety of speeds.
• Touring bicycles are more durable and comfortable, capable of transporting baggage, and may feature any type of gearing system.
• "Road bicycle"" is a more generic term which may refer to a bicycle with either racing or touring features, or a mixture of the two.
• Mountain bicycles, designed for off-road cycling, must combine relatively light weight with durability, and feature wide-gauge treaded tires, cross-wise handlebars to help the rider resist sudden jolts, and sometimes coiled-spring suspension systems.
• Track bicycles are ultra-simple, light bikes with but one speed which are designed for track cycling on purpose-built cycle tracks, often in velodromes.
• Cyclo-cross bicycles are lightweight enough to be carried over obstacles, and robust enough to be cycled through mud.

By means of propulsion:

• A pedal cycle is driven by pedals.
• A hand-cranked bicycle is driven by a hand crank.
• An electric bicycle assists the rider with an electric motor.
• A moped propels the rider with a motor, but includes bicycle pedals for human propulsion.

Other types:

• Utility bicycles, designed for commuting, shopping and running errands, are the norm in Europe, and employ middle or light weight frames and tires, dependable internal hub gears, and a variety of helpful accessories.
• Hybrid bicycles are a compromise between the mountain and racing style bicycles which replaced European-style utility bikes in North America in the early 1970s. They have a light frame, medium gauge wheels, and derailleur gearing, and feature straight or curved-back, touring handle bars for more upright riding.
• Cruisers are designed for comfort, with curved back handlebars, padded seats, and balloon tires. Cruisers typically have minimal gearing and are often available for rental at beaches and parks which feature flat terrain.
• BMX bicycles have small wheels and are used for bicycle motocross racing, as well as for wheelies, jumps, and other acrobatics.
• Freight bicycles are designed for transporting large or heavy loads.
• Velotaxis, pedicabs and trishaws are used to transport taxi passengers.
• Velomobiles provide all-weather pedal-powered transportation.

• Bicycle messenger
• Cycling
• List of bicycle manufacturers
• Bicycle path
• Mountain biking
• Cycling Hand Signals

• 1 Scientific American, March 1973: "Bicycle Technology", by S.S.Wilson.
• 2 "Johns Hopkins Gazette", Aug.30, 1999
• 3 The Economist, Feb.15, 2003
• 4 "Effective Cycling", by John Forester

• All About Bicycling, Rand McNally.
• Dick Teresi, Popular mechanics book of bikes and bicycling, Hearst Corp, 1975.
• The New Columbia Encyclopedia
• Richard Ballantine, Richard's Bicycle Book, Pan, 1975.
• Roni Sarig, The Everything Bicycle Book, Adams Media Corporation, 1997
• David B. Perry, Bike Cult: the Ultimate Guide to Human-powered Vehicles, Four Walls Eight Windows, 1995.

• Bicycle Photo Gallery (with Olympic winners' mountain bikes: An odd collection of bicycle related photographs and equipment
• Science of Cycling: Human Power: informative, nicely illustrated chapter on exercise physiology of bicycling
• Bicycle Safety: use of lights, rear-view mirrors, etc., and preventive maintenance to enhance bicycle safety
• Cycling Forums: Bicycle discussion forum
• Myths and Milestones in Bicycle Evolution: features an illustrated timeline of the history of the bicycle
• Bicycle Touring Resources Tips, packing lists, bibliography, travelogues, photographs and more
• Bicycle Repair in Wikibooks
• Bryan's Bicycle Page: an engineer and cyclist helps you choose the best bicycle for you
• Transportation Alternatives: Freight Cycles: the rationale for and how-to page for using bicycles for light hauling
• Mountain Bicycle Reviews: Mountain biking forum
• John Forester's Effective Cycling: cycling engineer discusses ways to better integrate bicycles into urban environments
• Cycle Publishing: The evidence against "Leonardo's bicycle"