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A thing that only has 2 wheels. It is sat on by a human and rode around the city. It is used for exercise and for fun, and for competition.
{{Other uses|Bicycle (disambiguation)}}
] of any kind, in the world is the Chinese ], with some 500 million in service.<ref name=Koeppel2007>{{Citation |title= Flight of the Pigeon |last= Koeppel |first= Dan |magazine= ] |date= January/February 2007 |volume= 48 |issue= 1 |ISSN=0006-2073 |publisher= ] |pages= 60–66 |url=http://books.google.com/books?id=isUDAAAAMBAJ&pg=PA60 |accessdate= 2012-01-28 }}</ref>]]

A '''bicycle''', often called a '''bike'''<ref>{{cite book
| title = ] | publisher = Oxford University Press | year = 1982 | edition = Second | quote = '''bike''' ''n''. 1. a. Colloq. abbrev. of bicycle ''n''.}}</ref> (and sometimes referred to as a "pushbike",<ref>{{cite book | title = ] | publisher = Oxford University Press | year = 1982 | edition = Second | quote = '''pushbike''' ''n.2'' 1. a. Colloq. abbrev. of bicycle ''n''.}}</ref> "pedal bike",<ref>{{cite book | title = ] | publisher = Oxford University Press | year = 1982 | edition = Second | quote = '''pedal bike''' ''n''. 2003 ''Yorks. Post'' (Nexis) 11 Nov., The first motorised Honda was a pedal bike fitted with an ex-military radio generator.}}</ref> "pedal cycle",<ref>{{cite book | title = ] | publisher = Oxford University Press | year = 1982 | edition = Second | quote = '''pedal cycle''' ''n''. 1905 ''Times'' 18 Nov. 13/2 The ground-floor is taken up with numerous stands of pedal cycles, motor cycles, and a number of motorcars.}}</ref> or "cycle"<ref>{{cite book | title = ] | publisher = Oxford University Press | year = 1982 | edition = Second | quote = '''cycle''' ''n''. II. 11. An abbreviation, familiar and conveniently inclusive, of bicycle and tricycle.}}</ref>), is a ], ], ], having two ] attached to a ], one behind the other.<ref>{{cite book | title = ] | publisher = Oxford University Press | year = 1982 | edition = Second | quote = '''bicycle''', ''n''. A vehicle consisting of two wheels held in a frame one behind the other, steered with handlebars on the front wheel and propelled by pedals.}}</ref> A person who rides a bicycle is called a ], or bicyclist.

Bicycles were introduced in the 19th century in Europe and now number more than a billion worldwide, twice as many as ]s.<ref>{{cite web |url=http://www.worldometers.info/bicycles/ |title=Bicycles produced in the world - Worldometers |author= |date= |work= |publisher= |accessdate=2 January 2012}}</ref> They are the principal ] in many regions. They also provide a popular form of recreation, and have been adapted for such uses as children's toys, general fitness, military and police applications, courier services and bicycle racing.

The basic shape and configuration of a typical ], or safety bicycle, has changed little since the first chain-driven model was developed around 1885.<ref name="herlihy">{{cite book
| title = Bicycle: the history
| last = Herlihy
| first = David V.
| authorlink = David V. Herlihy
| publisher = Yale University Press
| isbn = 0-300-10418-9
| pages = 200–250, 266–271, 280
| year = 2004}}</ref> However, many details have been improved, especially since the advent of modern materials and ]. These have allowed for a proliferation of specialized designs for diverse types of cycling.

The invention of the bicycle has had an enormous effect on society, both in terms of culture and of advancing modern industrial methods. Several components that eventually played a key role in the development of the automobile were invented for the bicycle, including ]s, ], chain-driven ], and ].<ref>Heitmann JA. The Automobile and American Life. McFarland, 2009, ISBN 0-7864-4013-9, pp. 11 and following</ref>

==Etymology==
The word ''bicycle'' was used in English print in the London '']'' in 1868, from the French term ''bicyclette'' which had been used as an adjective in 1847, and as a noun by 1868.<ref>", n.". ] Online (December 2012). Oxford University Press. 19 February 2013</ref> Before that, and in some places thereafter, bikes were known primarily as ]s.<ref>{{cite book|title=Bicycling Touring and Mountain Bike Basics|isbn=0-393-31337-9|year=1995|author=Peter Oliver|publisher=W.W. Norton & Company|page=12|quote=A Belgian newspaper, ''Le Gaulois'', is credited with coining the term, <nowiki>``bicycle,''</nowiki> in the 1890s. Before that — and in some places, thereafter — bikes were primarily known as velocipedes.}}</ref>

==History==
{{Main|History of the bicycle}}
]'' (around 1820), the first two-wheeler and as such the archetype of the bicycle]]
The ], also called Draisienne or laufmaschine, was the first human means of transport to use only two wheels in ] and was invented by the German ] ]. It is regarded as the forerunner of the modern bicycle and was introduced by Drais to the public in ] in summer 1817 and in Paris in 1818.<ref name="CSTM">{{cite web
| title = Canada Science and Technology Museum: Baron von Drais’ Bicycle
| year = 2006
| url = http://www.sciencetech.technomuses.ca/english/collection/cycles2.cfm| accessdate = 2006-12-23
| archiveurl= http://web.archive.org/web/20061229213036/http://www.sciencetech.technomuses.ca/english/collection/cycles2.cfm| archivedate= 29 December 2006 <!--DASHBot-->| deadurl= no}}</ref> Its rider sat astride a wooden frame supported by two in-line wheels and pushed the vehicle along with his/her feet while steering the front wheel.
]
]
The first mechanically-propelled 2-wheel vehicle may have been built by ], a Scottish blacksmith, in 1839, although the claim is often disputed.<ref>Herlihy (2004: 66–7)</ref> He is also associated with the first recorded instance of a ] traffic offense, when a ] newspaper in 1842 reported an accident in which an anonymous "gentleman from Dumfries-shire... bestride a velocipede... of ingenious design" knocked over a little girl in Glasgow and was fined five ]s.<ref>{{cite web|url=http://www.bbc.co.uk/news/magazine-13040607|title=Is dangerous cycling a problem?|publisher=BBC|date=13 April 2011|accessdate=13 April 2011| archiveurl= http://web.archive.org/web/20110414035046/http://www.bbc.co.uk/news/magazine-13040607| archivedate= 14 April 2011 <!--DASHBot-->| deadurl= no}}</ref>

In the early 1860s, Frenchmen ] and ] took bicycle design in a new direction by adding a mechanical ] drive with pedals on an enlarged front wheel (the ]). Another French inventor by the name of Douglas Grasso had a failed prototype of Pierre Lallement's bicycle several years earlier. Several inventions followed using rear-wheel drive, the best known being the rod-driven velocipede by Scotsman ] in 1869. The French creation, made of iron and wood, developed into the "]" (historically known as an "ordinary bicycle", a ], since there was then no other kind).<ref>Norcliffe, Glen. ''The Ride to Modernity: The Bicycle in Canada, 1869-1900'' (Toronto: University of Toronto Press, 2001), p.50, citing Derek Roberts.</ref> It featured a tubular steel frame on which were mounted wire-spoked wheels with solid rubber tires. These bicycles were difficult to ride due to their high seat and poor ]. In 1868 a Michaux cycle was brought to ], England by Rowley Turner, sales agent of the Coventry Sewing Machine Company (which soon became the Coventry Machinist Company). His uncle, Josiah Turner, together with business partner ] used this as a basis for the 'Coventry Model' in what became Britain's first cycle factory.<ref>McGrory, David. ''A History of Coventry'' (Chichester: Phillimore, 2003), p.221.</ref>

The ''dwarf ordinary'' addressed some of these faults by reducing the front wheel diameter and setting the seat further back. This necessitated the addition of gearing, effected in a variety of ways, to efficiently use the power available. Having to both pedal and steer via the front wheel remained a problem. ] (nephew of James Starley), J. H. Lawson, and Shergold solved this problem by introducing the ] (originated by the unsuccessful "bicyclette" of Englishman Henry Lawson),<ref>Norcliffe, p.47.</ref> connecting the frame-mounted cranks to the rear wheel. These models were known as ]s, dwarf safeties, or upright bicycles for their lower seat height and better weight distribution, although without pneumatic tires the ride of the smaller-wheeled bicycle would be much rougher than that of the larger-wheeled variety. Starley's 1885 ], manufactured in Coventry, England,<ref>McGrory, p.222.</ref> is usually described as the first recognizably modern bicycle. Soon, the ''seat tube'' was added, creating the double-triangle ''diamond frame'' of the modern bike.

Further innovations increased comfort and ushered in a second ], the 1890s' ''Golden Age of Bicycles''. In 1888, Scotsman ] introduced the first practical pneumatic tire, which soon became universal. Soon after, the rear ] was developed, enabling the rider to coast. This refinement led to the 1890s invention<ref>{{cite web
| url = http://www.sheldonbrown.com/coaster-brakes.html
| title = One-Speed Bicycle Coaster Brakes
| author = Sheldon Brown
| quote = Coaster brakes were invented in the 1890s.
| accessdate = 2010-12-01| archiveurl= http://web.archive.org/web/20101129160301/http://sheldonbrown.com/coaster-brakes.html| archivedate= 29 November 2010 <!--DASHBot-->| deadurl= no}}</ref> of ]s. ] and hand-operated ]-pull brakes were also developed during these years, but were only slowly adopted by casual riders. By the turn of the century, ]s flourished on both sides of the Atlantic, and touring and racing became widely popular.

Bicycles and horse buggies were the two mainstays of private transportation just prior to the automobile, and the grading of smooth roads in the late 19th century was stimulated by the widespread advertising, production, and use of these devices.<ref name="herlihy"/>{{rp|280}}

<gallery widths="200px" heights="200px">
File:Women on bicycles, late 19th Century USA.jpg|Women on bicycles on unpaved road, USA, late 19th Century
File:Ordinary bicycle01.jpg|A '']'' or ''ordinary bicycle'' photographed in the ] museum in the Czech Republic
File:BicyclePlymouth.jpg|Bicycle in ], England at the start of the 20th century
</gallery>

==Uses==
Bicycles have been and are employed for many uses:
*Utility: transportation, ], and ]
*Work: ], ]s, ], ], and ].
*Recreation: ], ], ], ], and play.
*]: ], ], ] and ] to multi-stage events like the ], ], the ], the ], the ], among others.
*Military: ], troop movement, supply of provisions, and patrol. See ].
*Entertainment and performance: ], ].

<gallery>
File:BicyclesMilkChurnsKolkata gobeirne.jpg|Transporting milk churns in ], India
File:Working bicycle.jpg|A ] in ], Netherlands
File:Children Bicycle.jpg|A toy, ], KPK, Pakistan.
</gallery>

==Technical aspects==
] in New York City]]
The bicycle has undergone continual adaptation and improvement since its inception. These innovations have continued with the advent of modern materials and computer-aided design, allowing for a proliferation of specialized bicycle types.

===Types===
{{Main|List of bicycle types}}

] ], an example of a bicycle designed for sport]]
Bicycles can be categorized in different ways: such as by function, by number of riders, by general construction, by gearing or by means of propulsion. The more common types include ]s, ]s, ]s, ]s, ]s, ]s, and ]. Less common are ], ], ]s, ], ], ] and ].

]s, ]s and ]s are not strictly bicycles, as they have respectively one, three and four wheels, but are often referred to informally as "bikes".
]

===Dynamics===
{{Main|Bicycle and motorcycle dynamics}}
A bicycle stays upright while moving forward by being steered so as to keep its ] over the wheels.<ref name=NS2581>{{cite journal
| last=Various
| date=9 December 2006
| title=Like falling off
| journal=]
| issue=2581
| page=93
| url=http://www.newscientist.com/article/mg19225812.400
| accessdate=27 January 2009}}</ref> This steering is usually provided by the rider, but under certain conditions may be provided by the bicycle itself.<ref name=MPRS>{{cite journal
| journal = Proc. R. Soc. A.
| volume = 463
| issue = 2084
| year = 2007
| pages = 1955–1982
| title = Linearized dynamics equations for the balance and steer of a bicycle: a benchmark and review
| last = Meijaard, Papadopoulos, Ruina, and Schwab
| doi = 10.1098/rspa.2007.1857
| first1 = J.P.
| last2 = Papadopoulos
| first2 = Jim M.
| last3 = Ruina
| first3 = Andy
| last4 = Schwab
| first4 = A.L.
| bibcode=2007RSPSA.463.1955M
}}</ref>

The combined center of mass of a bicycle and its rider must lean into a turn to successfully navigate it. This lean is induced by a method known as ], which can be performed by the rider turning the handlebars directly with the ]s<ref name="Wilson">{{cite book
| title = Bicycling Science
| edition = Third
| last = Wilson
| first = David Gordon
| coauthors = Jim Papadopoulos
| year = 2004
| publisher = The ]
| isbn = 0-262-73154-1
| pages = 270–272}}</ref> or indirectly by leaning the bicycle.<ref name="fajans">{{cite journal
| journal = American Journal of Physics
| volume = 68
| issue = 7
| month = July
| year = 2000
| last = Fajans
| first = Joel
| title = Steering in bicycles and motorcycles
| url = http://socrates.berkeley.edu/~fajans/pub/pdffiles/SteerBikeAJP.PDF
| format = PDF
| accessdate = 2006-08-04
| pages = 654–659
| doi = 10.1119/1.19504
| bibcode=2000AmJPh..68..654F| archiveurl= http://web.archive.org/web/20060901081011/http://socrates.berkeley.edu/~fajans/pub/pdffiles/SteerBikeAJP.PDF| archivedate= 1 September 2006 <!--DASHBot-->| deadurl= no}}</ref>

Short-wheelbase or tall bicycles, when braking, can generate enough stopping force at the front wheel to flip longitudinally.<ref>{{cite book
| title = Motorcycle Dynamics
| edition = Second
| last = Cossalter
| first = Vittore
| year = 2006
| publisher = Lulu.com
| isbn = 978-1-4303-0861-4
| pages = 241–342}}</ref> The act of purposefully using this force to lift the rear wheel and balance on the front without tipping over is a trick known as a ], endo or front wheelie.

===Performance===
{{Main|Bicycle performance}}
The bicycle is extraordinarily efficient in both biological and mechanical terms. The bicycle is the most efficient human-powered means of transportation in terms of energy a person must expend to travel a given distance.<ref>"Bicycle Technology", S.S. Wilson, ], March 1973</ref> From a mechanical viewpoint, up to 99% of the energy delivered by the rider into the pedals is transmitted to the wheels, although the use of gearing mechanisms may reduce this by 10–15%.<ref>
,
30 August 1999</ref><ref name="whitt">{{cite book
| title = Bicycling Science
| edition = Second
| last = Whitt
| first = Frank R.
| coauthors = David G. Wilson
| year = 1982
| publisher = Massachusetts Institute of Technology
| isbn = 0-262-23111-5
| pages = 277–300}}</ref>
In terms of the ratio of cargo weight a bicycle can carry to total weight, it is also an efficient means of cargo transportation.

] ]]

A human traveling on a bicycle at low to medium speeds of around {{Convert|10|–|15|mph|abbr=on}} uses only the energy required to walk. Air drag, which is proportional to the square of speed, requires dramatically higher power outputs as speeds increase. If the rider is sitting upright, the rider's body creates about 75% of the total drag of the bicycle/rider combination. Drag can be reduced by seating the rider in a more ]ally streamlined position. Drag can also be reduced by covering the bicycle with an aerodynamic ].

In addition, the ] generated in the production and transportation of the food required by the bicyclist, per mile traveled, is less than 1/10 that generated by energy efficient cars.<ref>{{cite web|url=http://www.kenkifer.com/bikepages/advocacy/bike_co2.htm |title=How Much Do Bicycles Pollute? Looking at the Carbon Dioxide Produced by Bicycles |publisher=Kenkifer.com |date=1999-11-20 |accessdate=2011-10-24}}</ref>

===Construction and parts===
In its early years, bicycle construction drew on pre-existing technologies. More recently, bicycle technology has in turn contributed ideas in both old and new areas.

====Frame====
{{Main|Bicycle frame}}

]

The great majority of today's bicycles have a frame with upright seating which looks much like the first chain-driven bike.<ref name="herlihy"/> Such upright bicycles almost always feature the ''diamond frame'', a ] consisting of two triangles: the front triangle and the rear triangle. The front triangle consists of the head tube, top tube, down tube and seat tube. The head tube contains the ], the set of bearings that allows the ] to turn smoothly for steering and balance. The top tube connects the head tube to the seat tube at the top, and the down tube connects the head tube to the ]. The rear triangle consists of the seat tube and paired chain stays and seat stays. The chain stays run parallel to the ], connecting the bottom bracket to the rear ], where the axle for the rear wheel is held. The seat stays connect the top of the seat tube (at or near the same point as the top tube) to the rear fork ends.

] with a ].]]
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 ] 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. This design, referred to as a '']'' or as an ''open frame'', allows the rider to mount and dismount in a dignified way while wearing a skirt or dress. While some women's bicycles continue to use this frame style, there is also a variation, the '']'', which splits the top tube laterally into two thinner top tubes that bypass the seat tube on each side and connect to the rear fork ends. The ease of stepping through is also appreciated by those with limited flexibility or other joint problems. Because of its persistent image as a "women's" bicycle, step-through frames are not common for larger frames.

Step-throughs were popular partly for practical reasons and partly for social mores of the day. For most of the history of bicycles' popularity women have worn long skirts, and the lower frame accommodated these better than the top-tube. Furthermore it was considered "unladylike" for women to open their legs to mount and dismount - in more conservative times women who rode bicycles at all were vilified as immoral or immodest. These practices were akin to the older practice of riding horse ].

Another style is the recumbent bicycle. These are inherently more aerodynamic than upright versions, as the rider may lean back onto a support and operate pedals that are on about the same level as the seat. The world's fastest bicycle is a recumbent bicycle but this type was banned from competition in 1934 by the ].<ref>{{cite web|url=http://www.recumbent-bikes-truth-for-you.com/history.html |title=History Loudly Tells Why The Recumbent Bike Is Popular Today |publisher=Recumbent-bikes-truth-for-you.com |date=1934-04-01 |accessdate=2011-10-24}}</ref>

Historically, materials used in bicycles have followed a similar pattern as in aircraft, the goal being high strength and low weight. Since the late 1930s alloy steels have been used for frame and fork tubes in higher quality machines. In the 1980s aluminum alloy frames and other components became popular due to their light weight, and most mid-range bikes are now principally aluminum alloy of some kind.{{Where?|date=August 2012}} More expensive bikes use ] due to its significantly lighter weight and profiling ability, allowing designers to make a bike both stiff and compliant by manipulating the lay-up. Other exotic frame materials include ] and advanced alloys. ], a natural ] with high strength-to-weight ratio and ]<ref name=Lakkad>{{cite journal |url=http://www.sciencedirect.com/science/article/pii/0015056881900233 |title=Mechanical properties of bamboo, a natural composite |last1=Lakkad |last2=Patel |journal=Fibre Science and Technology |volume=14 |issue=4 |date=June 1981 |pages=319–322}}</ref> has been used for bicycles since 1894.<ref name=lukenbill>{{cite web
| url = http://www.aboutmyplanet.com/environment/bamboo-bikes/
| title = About My Planet: Bamboo Bikes
| author = Jen Lukenbill
| accessdate =14 January 2013}}</ref>
Recent versions use bamboo for the primary frame with glued metal connections and parts, priced as exotic models.<ref name=lukenbill/><ref>{{cite web
| url=http://edition.cnn.com/2012/05/31/business/bamboo-bicycles-zambia-zambikes/index.html |publisher=CNN |date= may 31, 2012 |title=Made in Africa: Bamboo bikes put Zambian business on right track |author=Teo Kermeliotis }}</ref>
<ref>{{cite AV media |url=http://www3.nhk.or.jp/daily/english/ |publisher= NHK World News in English |title=Bamboo bicycles made in Zambia|date=14 Jan 2013 |location=Tokyo |medium=TV news}}</ref>

====Drivetrain and gearing====
]

{{Main|Bicycle drivetrain systems}}
The ''drivetrain'' begins with pedals which rotate the ], which are held in axis by the bottom bracket. Most bicycles use a chain to transmit power to the rear wheel. A very small number of bicycles use a shaft drive to transmit power, or special belts. Hydraulic bicycle transmissions have been built, but they are currently inefficient and complex.

Since cyclists' legs are most efficient over a narrow range of pedaling speeds, or ], a variable ] helps a cyclist to maintain an optimum pedalling speed while covering varied terrain. Some, mainly utility, bicycles use hub gears with between 3 and 14 ratios, but most use the generally more efficient dérailleur system, by which the chain is moved between different cogs called chainrings and sprockets in order to select a ratio. A dérailleur system normally has two dérailleurs, or mechs, one at the front to select the ] and another at the back to select the sprocket. Most bikes have two or three chainrings, and between 5 and 11 sprockets on the back, with the number of theoretical gears calculated by multiplying front by back. In reality, many gears overlap or require the chain to run diagonally, so the number of usable gears is fewer.

] are appropriate for different people and styles of cycling. Multi-speed bicycles allow gear selection to suit the circumstances: a cyclist could use a high gear when cycling downhill, a medium gear when cycling on a flat road, and a low gear when cycling uphill. In a lower gear every turn of the pedals leads to fewer rotations of the rear wheel. This allows the energy required to move the same distance to be distributed over more pedal turns, reducing fatigue when riding uphill, with a heavy load, or against strong winds. A higher gear allows a cyclist to make fewer pedal turns to maintain a given speed, but with more effort per turn of the pedals.

] instead of a chain]]

With a ''chain drive'' transmission, a ''chainring'' attached to a crank drives the chain, which in turn rotates the rear wheel via the rear sprocket(s) (] or ]). There are four gearing options: two-speed hub gear integrated with chain ring, up to 3 chain rings, up to 11 sprockets, hub gear built into rear wheel (3-speed to 14-speed). The most common options are either a rear hub or multiple chain rings combined with multiple sprockets (other combinations of options are possible but less common).

====Steering and seating====
The ] turn the fork and the front wheel via the ], which rotates within the headset. Three styles of handlebar are common. ''Upright handlebars'', the norm in Europe and elsewhere until the 1970s, curve gently back toward the rider, offering a natural grip and comfortable upright position. ''Drop handlebars'' "drop" as they curve forward and down, offering the cyclist best braking power from a more aerodynamic "crouched" position, as well as more upright positions in which the hands grip the brake lever mounts, the forward curves, or the upper flat sections for increasingly upright postures. Mountain bikes generally feature a 'straight handlebar' or 'riser bar' with varying degrees of sweep backwards and centimeters rise upwards, as well as wider widths which can provide better handling due to increased leverage against the wheel.

]
] also vary with rider preference, from the cushioned ones favored by short-distance riders to narrower saddles which allow more room for leg swings. Comfort depends on riding position. With comfort bikes and hybrids, cyclists sit high over the seat, their weight directed down onto the saddle, such that a wider and more cushioned saddle is preferable. For racing bikes where the rider is bent over, weight is more evenly distributed between the handlebars and saddle, the hips are flexed, and a narrower and harder saddle is more efficient. Differing saddle designs exist for male and female cyclists, accommodating the genders' differing anatomies, although bikes typically are sold with saddles most appropriate for men.

A recumbent bicycle has a reclined ] that some riders find more comfortable than a saddle, especially riders who suffer from certain types of seat, back, neck, shoulder, or wrist pain. Recumbent bicycles may have either under-seat or over-seat ].

====Brakes====
{{Main|Bicycle brake systems}}
] trademark: V-Brake, on rear wheel of a ]]]
Modern bicycle ''brakes'' may be: ''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'', with a separate rotor for braking. ] are more common for mountain bikes, tandems and recumbent bicycles than on road-specific bicycles, due to their increased weight and complexity.

] and hub]]
With hand-operated brakes, force is applied to brake levers mounted on the handlebars and transmitted via Bowden cables or ] lines to the friction pads, which apply pressure to the braking surface, causing friction which slows the bicycle down. A rear hub brake may be either hand-operated or pedal-actuated, as in the back pedal ''coaster brakes'' which were popular in North America until the 1960s.

]s do not have brakes, because all riders ride in the same direction around a track which does not necessitate sharp deceleration. Track riders are still able to slow down because all track bicycles are fixed-gear, meaning that there is no freewheel. Without a freewheel, coasting is impossible, so when the rear wheel is moving, the cranks are moving. To slow down, the rider applies resistance to the pedals, acting as a braking system which can be as effective as a conventional rear wheel brake, but not as effective as a front wheel brake.<ref>{{cite web
| url = http://www.sheldonbrown.com/fixed.html
| title = Fixed Gear Conversions: Braking
| last = Brown
| first = Sheldon
| accessdate = 2009-02-11| archiveurl= http://web.archive.org/web/20090209002353/http://sheldonbrown.com/fixed.html| archivedate= 9 February 2009 <!--DASHBot-->| deadurl= no}}</ref>

====Suspension====
{{Main|Bicycle suspension}}

Bicycle suspension refers to the system or systems used to ''suspend'' the rider and all or part of the bicycle. This serves two purposes: to keep the wheels in continuous contact with the ground, improving control, and to isolate the rider and luggage from jarring due to rough surfaces, improving comfort.

Bicycle suspensions are used primarily on mountain bicycles, but are also common on hybrid bicycles, as they can help deal with problematic vibration from poor surfaces. Suspension is especially important on recumbent bicycles, since while an upright bicycle rider can stand on the pedals to achieve some of the benefits of suspension, a recumbent rider cannot.

Basic mountain bicycles and hybrids usually have front suspension only, whilst more sophisticated ones also have rear suspension. Road bicycles tend to have no suspension, due to weight and stiffness concerns, although may have special designs to increase compliance.

====Wheels and tires====
{{Main|Bicycle wheel|Bicycle tire}}

The wheel axle fits into fork ends in the frame and fork. A pair of wheels may be called a wheelset, especially in the context of ready-built "off the shelf", performance-oriented wheels.

Tires vary enormously depending on their intended purpose. ] use tires 18 to 25 millimeters wide, most often completely smooth, or ], and inflated to high pressure in order to roll fast on smooth surfaces. Off-road tires are usually between {{Convert|38|and|64|mm|abbr=on}} wide, and have treads for gripping in muddy conditions or metal studs for ice.

====Accessories====
], fenders/mud-guards, water bottles in ], four ]s and a handlebar bag.]]

Some components, which are often optional accessories on sports bicycles, are standard features on utility bicycles to enhance their usefulness and comfort. ]s, or ]s, protect the cyclist and ] from spray when riding through wet areas and ]s protect clothes from oil on the chain while preventing clothing from being caught between the chain and ] teeth. ]s keep a bicycle upright when parked, while a ] will help prevent it from being stolen. Front-mounted ] for carrying goods are often used. ]s and ]s mounted above the rear tire can be used to carry equipment or cargo. Parents sometimes add rear-mounted ] and/or an auxiliary saddle fitted to the crossbar to transport children.

] and ''toestraps'' and ] help keep the foot locked in the proper position on the pedals, and enable the cyclist to pull as well as push the pedals—although not without their hazards, e.g. may lock foot in when needed to prevent a fall. Technical accessories include ]s for measuring speed, distance, heart rate, GPS data etc. Other accessories include ], reflectors, ], mirror, water bottles and ], and ].<ref name="bicycleuniverse">{{cite web|url=http://bicycleuniverse.info/eqp/accessories.html#safety |title=Safety Accessories |accessdate=2006-09-13 |last=Bluejay |first=Michael |work=Bicycle Accessories |publisher=BicycleUniverse.info| archiveurl= http://web.archive.org/web/20061008024853/http://bicycleuniverse.info/eqp/accessories.html| archivedate= 8 October 2006 <!--DASHBot-->| deadurl= no}}</ref>

]s may help reduce injury in the event of a collision or accident, and a certified helmet is legally required for some riders in some jurisdictions. Helmets are classified as an accessory<ref name="bicycleuniverse" /> or an item of clothing by others.<ref>{{cite web|url=http://bicycling.about.com/library/weekly/aa041098.htm |title=The Essentials of Bike Clothing |accessdate=2006-09-13 |work=About Bicycling |publisher=About.com| archiveurl= http://web.archive.org/web/20060826085232/http://bicycling.about.com/library/weekly/aa041098.htm| archivedate= 26 August 2006 <!--DASHBot-->| deadurl= no}}</ref>

====Tools====
] to clean off an area of the inner tube around the puncture, a tube of rubber solution (] fluid), round and oval patches, a metal grater and piece of chalk to make chalk powder (to dust over excess rubber solution). Kits often also include a wax crayon to mark the puncture location.]]
{{main|Bicycle tools}}

There are specialized bicycle tools for use both in the shop and on the road. Many cyclists carry tool kits. These may include a tire patch kit (which, in turn, may contain any combination of a ] or ], ]s, spare ], self-adhesive patches, or tube-patching material, an adhesive, a piece of sandpaper or a metal grater (for roughing the tube surface to be patched),<ref>{{cite web
| url = http://sheldonbrown.com/flats.html#patching
| title = Sheldon Brown: Flat tires
| accessdate = 2008-05-29| archiveurl= http://web.archive.org/web/20080513032548/http://www.sheldonbrown.com/flats.html| archivedate= 13 May 2008 <!--DASHBot-->| deadurl= no}}</ref><ref>{{cite web
| url = http://www.bikewebsite.com/bikeop.htm
| title = BikeWebSite: Bicycle Glossary – Patch kit
| accessdate = 2008-06-20| archiveurl= http://web.archive.org/web/20080513060825/http://www.bikewebsite.com/bikeop.htm| archivedate= 13 May 2008 <!--DASHBot-->| deadurl= no}}</ref> and sometimes even a block of ].), ]es, ]s, screwdrivers, and a ]. There are also cycling specific ]s that combine many of these implements into a single compact device. More specialized bicycle components may require more complex tools, including proprietary tools specific for a given manufacturer.

====Maintenance and repair====
<!-- ] links to this section. ~~~~ -->

] in ], Georgia.]]

Some bicycle parts, particularly hub-based gearing systems, are complex. ], assisted-service, and full-service bicycle ] options exist.

* Some cyclists choose self-service: they maintain their own bicycles, perhaps as part of their enjoyment of the hobby of cycling or simply for economic reasons.
* There exist several hundred assisted-service ]s worldwide.<ref>{{cite web|title=Community Bicycle Organizations|url=http://www.bikecollectives.org/index.php?title=Community_Bicycle_Organizations|work=Bike Collective Network wiki|accessdate=15 January 2013}}</ref> At a co-op, ] bring in bicycles needing repair or maintenance; volunteers teach them how to do the required steps.
* Full service is available from ]s at a ]. In areas where it is available,<ref>{{cite web|title=Google Search - bicycle roadside assistance|url=http://www.google.com/search?q=bicycle+roadside+assistance|publisher=Google, Inc|accessdate=16 January 2013}}</ref> some cyclists purchase roadside assistance from companies such as the ] or the ].

====Standards====
A number of formal and industry standards exist for bicycle components to help make spare parts exchangeable and to maintain a minimum product safety.

The ] (ISO) has a special technical committee for cycles, TC149, that has the following scope: "Standardization in the field of cycles, their components and accessories with particular reference to terminology, testing methods and requirements for performance and safety, and interchangeability."

The ] (CEN) also has a specific Technical Committee, TC333, that defines European standards for cycles. Their mandate states that EN cycle standards shall harmonize with ]. Some CEN cycle standards were developed before ISO published their standards, leading to strong European influences in this area. European cycle standards tend to describe minimum safety requirements, while ISO standards have historically harmonized parts geometry.<ref>The TC149 ISO bicycle committee, including the TC149/SC1 ("Cycles and major sub-assemblies") subcommittee, has published the following standards:{{Citation needed|date=December 2012}}
* ] Cycles—Safety requirements for bicycles
* ] Cycles—Marking of cycle components
* ] Cycles—Pedal axle and crank assembly with square end fitting—Assembly dimensions
* ] Cycles—Screw threads used in bottom bracket assemblies
* ] Cycles—Hubs and freewheels—Assembly dimensions
* ] Cycles—Screw threads used to assemble freewheels on bicycle hubs
* ] Cycles—Stem and handlebar bend—Assembly dimensions
* ] Cycles—External dimensions of spoke nipples
* ] Cycles—Lighting and retro-reflective devices—Photometric and physical requirements
* ] Cycles—Terminology (same as BS 6102-4)
* ] Cycles—Safety requirements for bicycles for young children
* ] Cycles—Screw threads used to assemble head fittings on bicycle forks
* ] Cycles—Stem wedge angle
* ] Cycles—Splined hub and sprocket—Mating dimensions
* ] Cycles—Luggage carriers for bicycles—Concepts, classification and testing

Other ISO Technical Committees have published various cycle relevant standards, for example:
* ] Bicycle tire and rim designations
* ] Cycle chains—Characteristics and test methods

Published cycle standards from CEN TC333 include:
* ] City and trekking bicycles – Safety requirements and test methods
* ] Bicycles for young children – Safety requirements and test methods
* ] Mountain-bicycles – Safety requirements and test methods
* ] Racing bicycles – Safety requirements and test methods
* ] Bicycles – Accessories for bicycles – Luggage carriers
* ] Cycles – Requirements and test methods for cycle locks

Yet to be approved cycle standards from CEN TC333:
* ] Cycles—Electrically power assisted cycles (] bicycle)
* ] Cycles—Terminology
* 00333011 Cycles – Bicycles trailers – safety requirements and test methods</ref>

====Parts====

For details on specific bicycle parts, see ] and ].
<!-- *] -->
<!-- *] -->
<!-- *] -->

==Social and historical aspects==
The bicycle has had a considerable effect on human society, in both the cultural and industrial realms.

===In daily life===

Around the turn of the 20th century, bicycles reduced crowding in inner-city tenements by allowing workers to commute from more spacious dwellings in the suburbs. They also reduced dependence on horses. 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.

] ]]]
A number of cities around the world have implemented schemes known as ]s or community bicycle programs.<ref>{{cite journal|last=Shaheen|first=Susan|coauthors=Guzman, S., and H. Zhang|title=Bikesharing in Europe, the Americas, and Asia: Past, Present, and Future|journal=Transportation Research Record: Journal of the Transportation Research|year=2010|url=http://76.12.4.249/artman2/uploads/1/Bikesharing_in_Europe__the_Americas__and_Asia.pdf}}</ref><ref>{{cite journal|last=Shaheen|first=Stacey|coauthors=Stacey Guzman|title=Worldwide Bikesharing|journal=ACCESS: the Magazine of UCTC|year=2011|url=http://uctc.net/access/39/access39_bikesharing.shtml}}</ref> The first of these was the White Bicycle plan in ] in 1965 which was followed by yellow bicycles in ] and green bicycles in ]. These initiatives complement a city's public transport system and offer an alternative to motorized traffic to help reduce congestion and pollution.<ref>{{cite journal|last=Shaheen|first=Susan|coauthors=Zhang, H., Martin, E., and S. Guzman|title=Hangzhou Public Bicycle: Understanding Early Adoption and Behavioral Response to Bikesharing in Hangzhou, China|journal=Transportation Research Record. Journal of the Transportation Research Board|year=2011|url=http://76.12.4.249/artman2/uploads/1/China___s_Hangzhou_Public_Bicycle.pdf}}</ref> In Europe, especially in The Netherlands and parts of Germany and Denmark, commuting by bicycle is very common. In the Danish capital of ], a cyclists' organization runs a Cycling Embassy, that promotes biking for commuting and sightseeing. The United Kingdom has a tax break scheme (IR 176) that allows employees to buy a new bicycle tax free to use for commuting.<ref></ref>

In The Netherlands all train stations are equipped with provisions for bicycle parking for free, or a more secure parking place for a small fee, with the larger stations also offering bicycle repair shops. Cycling is so popular that the parking capacity may be exceeded, while in some places such as Delft the capacity is usually exceeded.<ref>{{cite web
| url = http://www.nrc.nl/international/article2482297.ece/So_many_bikes%2C_so_little_space
| title = So many bikes, so little space
| author = Joel Broekaert and Reinier Kist
| date = 12 February 2010
| publisher = NRC Handelsblad
| accessdate = 2010-02-13}}</ref> In ] in Norway, the ] has been developed to encourage cyclists by giving assistance on a steep hill. Buses in many cities have ]s mounted on the front.

There are towns in some countries where ] has been an integral part of the landscape for generations, even without much official support. That is the case of ], in Portugal.

In cities where the bicycle is not an integral part of the planned transportation system, commuters often use bicycles as elements of a ], where the bike is used to travel to and from train stations or other forms of rapid transit. Some students who commute several miles drive a car from home to a campus parking lot, then ride a bicycle to class. ]s are useful in these scenarios, as they are less cumbersome when carried aboard. Los Angeles removed a small amount of seating on some trains to make more room for bicycles and wheel chairs.<ref>{{cite web
| url = http://la.streetsblog.org/2008/10/16/metro-making-room-for-bikes-on-their-trains/
| title = Metro Making Room for Bikes on Their Trains
| author = Damien Newton
| date = October 16, 2008
| publisher = LA.StreetsBlog.Org
| accessdate = 2010-02-12}}</ref>
]

Some US companies, notably in the ], are developing both innovative cycle designs and cycle-friendliness in the workplace. ] is working to encourage use of a seven-person four-wheel<ref>. Retrieved 2012-02-22.</ref> "]", employing riders' muscle energy while also allowing conversational interaction. ], whose ] ] "pedaled to pitch meetings ... was raising money from ]" on a two-wheeler, chose a new location for its ] headquarters "based on where biking would be easy". Parking in the office was also integral to HQ planning. Mitchell Moss, who runs the ] at ], said in 2012: "Biking has become the mode of choice for the educated high tech worker."<ref>Bernstein, Andrea, , '']'', February 22, 2012. "Bernstein reports from the project at ]." Retrieved 2012-02-22.</ref>

Bicycles offer an important mode of transport in many developing countries. Until recently, bicycles have been a staple of everyday life throughout Asian countries. They are the most frequently used method of transport for commuting to work, school, shopping, and life in general. They also offer a degree of exercise to keep the individual healthy.<ref>http://www.worldwatch.org/files/pdf/WP90BICYCLE.pdf</ref>

Bicycles are also celebrated through use of visual art. An example of bicycles being appreciated through use of art, music, and film is the ], a film festival hosted all around the world.

===Poverty alleviation===

Experiments done in Uganda, Tanzania and Sri Lanka on hundreds of households have shown that a bicycle can increase the income of a poor family by as much as 35%.<ref>{{cite web
| url = http://www.bicyclepotential.org/
| title = Bicycle: The Unnoticed Potential
| publisher = BicyclePotential.org
| year = 2009
| accessdate = 2011-07-09| archiveurl= http://web.archive.org/web/20110625154846/http://www.bicyclepotential.org/| archivedate= 25 June 2011 <!--DASHBot-->| deadurl= no}}</ref>{{Better source|date=January 2013}}<ref>{{cite journal
| author = Niklas Sieber
| journal = Journal of Transport Geography
| title = Appropriate Transportation and Rural Development in Makete District, Tanzania
| year = 1998
| volume = 6
| issue = 1
| pages = 69–73
| url = http://www.niklas-sieber.de/Publications/TransGeo98.pdf
| format = PDF
| accessdate = 2011-07-09
| doi = 10.1016/S0966-6923(97)00040-9}}</ref><ref>{{cite web
| url = http://www.worldbicyclerelief.org/_images/pdfs/tsunami_measurement.pdf
| title = Project Tsunami Report Confirms The Power of Bicycle
| publisher = World Bicycle Relief
| accessdate = 2011-07-09}}</ref> Transport, if analyzed for the cost-benefit analysis for rural ], has given one of the best returns in this regard. For example, road investments in India were a staggering 3-10 times more effective than almost all other investments and subsidies in rural economy in the decade of 1990s. What a road does at a macro level to increase transport, the bicycle supports at the micro level. The bicycle, in that sense, can be one of the best means to eradicate poverty in poor nations.

===Female emancipation===
] learning to ride a bicycle.<ref name=Willard1895/>]]
The safety bicycle gave women unprecedented mobility, contributing to ] 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 symbolize the ] of the late 19th century, especially in Britain and the United States.<ref name="herlihy"/>{{rp|266–271}} The ] in the 1890s also led to a movement for so-called ], which helped liberate women from corsets and ankle-length skirts and other restrictive garments, substituting the then-shocking ].<ref name="herlihy"/>{{rp|266–271}}

The bicycle was recognized by 19th-century feminists and ]s as a "freedom machine" for women. American ] said in a '']'' interview on February 2, 1896:
"I think it has done more to emancipate woman than any one thing in the world. I rejoice every time I see a woman ride by on a wheel. It gives her a feeling of self reliance and independence the moment she takes her seat; and away she goes, the picture of untrammelled womanhood."<ref name=HustedHarper1898/> In 1895 ], the tightly laced president of the ], wrote ''A Wheel Within a Wheel: How I Learned to Ride the Bicycle, with Some Reflections by the Way'', a 75 page illustrated memoir praising "Gladys", her bicycle, for its "gladdening effect" on her health and political optimism.<ref name=Willard1895/> Willard used a cycling metaphor to urge other suffragists to action.<ref name=Willard1895/>

===Economic implications===
] advertisement from 1886]]
] 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 ]s, ]s, and sprockets. These techniques later enabled skilled metalworkers and mechanics to develop the components used in early automobiles and aircraft.

They also served to teach the industrial models later adopted, including mechanization and ] (later copied and adopted by ] and ]),<ref>Norcliffe, Glen. ''The Ride to Modernity: The Bicycle in Canada, 1869-1900'' (Toronto: University of Toronto Press, 2001), pp.23, 106, & 108. GM's practice of sharing chassis, bodies, and other parts is exactly what the early bicycle manufacturer Pope was doing.</ref> vertical integration<ref>Norcliffe, p.106.</ref> (also later copied and adopted by Ford), aggressive advertising<ref>Norcliffe, pp.142–47.</ref> (as much as 10% of all advertising in U.S. periodicals in 1898 was by bicycle makers),<ref>Norcliffe, p.145.</ref> lobbying for better roads (which had the side benefit of acting as advertising, and of improving sales by providing more places to ride),<ref name="Norcliffe, p.108">Norcliffe, p.108.</ref> all first practiced by Pope.<ref name="Norcliffe, p.108" /> In addition, bicycle makers adopted the annual model change<ref>Norcliffe, p.23.</ref><ref>Babaian, Sharon. ''The Most Benevolent Machine: A Historical Assessment of Cycles in Canada'' (Ottawa: National Museum of Science and Technology, 1998), p.97.</ref> (later derided as ], and usually credited to General Motors), which proved very successful.<ref>Babaian, p.98.</ref>

Early bicycles were an example of ], being adopted by the fashionable elites.<ref>Norcliffe, pp.8, 12, 14, 23, 147–8, 187–8, 208, & 243–5.</ref> In addition, by serving as a platform for accessories, which could ultimately cost more than the bicycle itself, it paved the way for the likes of the ].<ref>Norcliffe, pp.23, 121, & 123.</ref>

Bicycles helped create, or enhance, new kinds of businesses, such as bicycle messengers,<ref>Norcliffe, p.212.</ref> traveling seamstresses,<ref>Norcliffe, p.214.</ref> riding academies,<ref>Norcliffe, p.131.</ref> and racing rinks<ref>Norcliffe, p.30 & 131.</ref> Their board tracks were later adapted to early ] and ]. There were a variety of new inventions, such as ] tighteners,<ref>Norcliffe, p.125.</ref> and specialized lights,<ref>Norcliffe, p.123 & 125.</ref> socks and shoes,<ref>Norcliffe, p.125 & 126.</ref> and even cameras, such as the ]'s Poco.<ref>Norcliffe, p.238.</ref> Probably the best known and most widely used of these inventions, adopted well beyond cycling, is Charles Bennett's Bike Web, which came to be called the ].<ref>Norcliffe, p.128.</ref>

], ]]]
They also presaged a move away from public transit<ref>Norcliffe, p.214–5.</ref> that would explode with the introduction of the automobile.

J. K. Starley's company became the Rover Cycle Company Ltd. in the late 1890s, and then simply the ] when it started making cars. ] (in ]) and ] also began in the bicycle business, as did the ].<ref>
{{cite web
| title = The Wrights' bicycle shop
| year = 2007
| url = http://www.nasm.si.edu/Wrightbrothers/who/1893/shop.cfm
| accessdate = 2007-02-05
| archiveurl= http://web.archive.org/web/20070125080218/http://www.nasm.si.edu/wrightbrothers/who/1893/shop.cfm| archivedate= 25 January 2007 <!--DASHBot-->| deadurl= no}}</ref> Alistair Craig, whose company eventually emerged to become the engine manufacturers ], also started from manufacturing bicycles, in Glasgow in March 1885.

In general, U.S. and European cycle manufacturers used to assemble cycles from their own frames and components made by other companies, although very large companies (such as Raleigh) used to make almost every part of a bicycle (including bottom brackets, axles, etc.) In recent years, those bicycle makers have greatly changed their methods of production. Now, almost none of them produce their own frames.

Many newer or smaller companies only design and market their products; the actual production is done by Asian companies. For example, some 60% 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.<ref>
{{Cite news
| author = Francois Bougo
| title = Beijing looks to revitalise bicycle culture
| url = http://www.google.com/hostednews/afp/article/ALeqM5iQeSSys_rKGJ7ve4u1ZsVyIA_LmQ
| publisher = Agence France-Presse
| date = May 26, 2010
}}</ref>
One of the major reasons for the proliferation of Chinese-made bicycles in foreign markets is the lower cost of labor in China.<ref>], 15 February 2003</ref>

One of the profound economic implications of bicycle use is that it liberates the user from oil consumption.(Ballantine, 1972) The bicycle is an inexpensive, fast, healthy and environmentally friendly mode of transport.(Illich, 1974)

In line with the European financial crisis, in Italy in 2011 the number of bicycle sales (1.75 million) just passed the number of new car sales.<ref>{{cite web |url=http://www.bbc.co.uk/news/world-europe-19801599 |title=Italian bicycle sales 'surpass those of cars' |date=October 2, 2012}}</ref>

===Manufacturing===
{{See also|List of bicycle manufacturing companies}}
The global bicycle market is $61 billion in 2011.<ref>{{cite web|url=http://seekingalpha.com/article/133109-high-growth-and-big-margins-in-the-61-billion-bicycle-industry |title=High Growth and Big Margins in the $61 Billion Bicycle Industry |publisher=Seeking Alpha |date= |accessdate=2011-10-24}}</ref> {{As of|2009}} 130 million bicycles were sold every year globally and 66% of them were made in China.<ref>{{cite web|url=http://www.dare.co.in/opportunities/manufacturing/the-business-of-bicycles.htm |title=The Business of Bicycles &#124; Manufacturing &#124; Opportunities &#124; DARE - Because Entrepreneurs Do &#124; |publisher=DARE |date=2009-06-01 |accessdate=2011-10-24}}</ref>

===Legal requirements===
{{Main|Bicycle law}}
Early in its development, as with ]s, there were restrictions on the operation of bicycles. Along with advertising, and to gain free publicity, ] litigated on behalf of cyclists.<ref>Norcliffe, Glen. ''The Ride to Modernity: The Bicycle in Canada, 1869-1900'' (Toronto: University of Toronto Press, 2001), p.108.</ref>

The 1968 ] of the ] considers a bicycle to be a vehicle, and a person controlling a bicycle (whether actually riding or not) is considered an operator. The traffic codes of many countries reflect these definitions and demand that a bicycle satisfy certain legal requirements before it can be used on public roads. In many ]s, it is an offense to use a bicycle that is not in a roadworthy condition.

In most jurisdictions, bicycles must have functioning front and rear lights when ridden after dark. As some generator or ]-driven lamps only operate while moving, rear ] are frequently also mandatory. Since a moving bicycle makes little noise, some countries insist that bicycles have a warning bell for use when approaching pedestrians, equestrians, and other cyclists, though sometimes a ] can be used when a 12 volt battery is available.

Some countries require child and/or adult cyclists to wear helmets, as this may protect riders from head trauma. Countries which require adult cyclists to wear helmets include Spain, ] and Australia. Mandatory helmet wearing is one of the most controversial topics in the cycling world, with proponents arguing that it reduces head injuries and thus is an acceptable requirement, while opponents argue that by making cycling seem more dangerous and cumbersome, it reduces cyclist numbers on the streets, creating an overall negative health effect (fewer people cycling for their own health, and the remaining cyclists being more exposed through a reversed ] effect).

==See also==
{{Portal|Cycling}}
{{Outline|Outline of bicycles}}
{{Spoken Misplaced Pages|EN_Bicycle.ogg|2007-12-07}}
* ] – use of bicycles for ], ], or for ].
* ] — practices to reduce risk associated with cycling
* ]
* ]
* ]

==Notes==
{{Reflist|30em|refs=
<ref name=HustedHarper1898>{{Citation |url= http://books.google.com/books?id=ADgQAQAAMAAJ&dq=I'll%20tell%20you%20what%20I%20think%20of%20bicycling&pg=PA858#v=snippet&q=%22I'll%20tell%20you%20what%20I%20think%20of%20bicycling%22%20%22I%20think%20it%20has%20done%20more%20to%20emancipate%20woman%20than%20any%20one%20thing%20in%20the%20world%22&f=false |title= The life and work of Susan B. Anthony: including public addresses, her own letters and many from her contemporaries during fifty years. A story of the evolution of the status of woman, Volume 2 |volume=2 |first= Ida |last= Husted Harper |authorlink=Ida Husted Harper |publisher= The Bowen-Merrill Company |year= 1898 }}</ref>

<ref name=Willard1895>{{citation |url=http://books.google.com/books?id=CUAfAAAAYAAJ&printsec=frontcover#v=onepage&q&f=false |title= A Wheel Within a Wheel: How I Learned to Ride the Bicycle, with Some Reflections by the Way |first=Frances Elizabeth |last= Willard |authorlink=Frances Willard (suffragist) |publisher= ] |year= 1895 |pages=53, 56 }}</ref>

}}
<!-- The following notes were found to not be in use when converting to cite.php:
*3 "The Stability of the Bicycle", David Jones, "Physics Today", April 1970: pp.34-40 (external link, below)
*4 Townsend (external link, below)
*6 "Cities for Cyclists" (external link, below)
*8 ], John Forester
-->

==References==
* ''All About Bicycling'', Rand McNally.
<!--* ''The New Columbia Encyclopedia'' (This reference is overly broad) -->
* ], ''Richard's Bicycle Book'', Pan, 1975.
* Caunter C. F. ''The History and Development of Cycles'' Science Museum London 1972.
* David B. Perry, ''Bike Cult: the Ultimate Guide to Human-powered Vehicles'', Four Walls Eight Windows, 1995.
* Roni Sarig, ''The Everything Bicycle Book'', Adams Media Corporation, 1997
* {{cite web | title=Randonneurs USA | work=PBP: Paris-Brest-Paris | url=http://www.rusa.org/pbp.html |date=March 31, 2005}}
*US Department of Transportation, Federal Highway Administration. "America's Highways 1776-1976", pp.&nbsp;42–43. Washington, DC, US Government Printing Office.
* ], ''Bicycling Science'', MIT press, ISBN 0-262-73154-1
* Frank Berto, ''The Dancing Chain: History and Development of the Derailleur Bicycle'', San Francisco: Van der Plas Publications, 2005, ISBN 1-892495-41-4.
* ''The Data Book: 100 Years of Bicycle Component and Accessory Design'', San Francisco: Van der Plas Publications, 2005, ISBN 1-892495-01-5.
* Shonquis Moreno and Ole Wagner, ''Velo: bicycle culture and design''. Edited by Robert Klanten and Sven Ehmann. Berlin: Gestalten, 2010, ISBN 978-3-89955-284-3

==External links==
{{Sister project links|voy=Cycling|wikt=bicycle|q=Cycling|s=1911 Encyclopædia Britannica/Bicycle|b=Bicycles/Maintenance and Repair}}
{{Commons category|Bicycles}}
* The world's largest bicycle museum
* A range of produced by the ] covering cycling.
* at the ]

{{Human-powered vehicles}}
{{Cycling}}
{{Bike equipment}}

]
]
]
]
]

Revision as of 18:55, 2 April 2013

A thing that only has 2 wheels. It is sat on by a human and rode around the city. It is used for exercise and for fun, and for competition.