Absolutely!

Here’s a detailed and comprehensive guide about bicycles, covering

their history, components, types, mechanics, benefits, and future innovations.

🚴‍♂️ Complete Guide to Bicycles (Bikes)

A bicycle is a two-wheeled human-powered vehicle that has transformed how
people move, exercise, and even compete. It’s a symbol of freedom,
sustainability, and engineering ingenuity, with more than 1 billion bikes currently
in use worldwide.

1. 🛠️ What Is a Bicycle?
A bicycle (or bike) is a human-powered vehicle with:

●​ Two wheels​

●​ A frame​

●​ Pedals​

●​ Handlebars​

●​ A saddle (seat)​
It converts human energy into mechanical motion, making it a highly efficient
mode of transport.

2. 🕰️ History of the Bicycle

Year Milestone

1817 Draisine (Laufmaschine): Wooden “running machine” by Karl von

Drais (Germany)

1860s Velocipede ("boneshaker") with pedals on front wheel

1885 Safety bicycle invented — chain drive and similar to today’s

design

1900s Mass production begins, becomes widely affordable

1970s–tod Rise of specialized bikes: mountain, racing, hybrid, electric

ay

3. ⚙️ Key Components of a Bicycle

🧱 Frame
●​ Material: Steel, aluminum, carbon fiber, titanium​

●​ Determines geometry, weight, and durability.​

🛞 Wheels
●​ Rims, spokes, hubs, and tires.​

●​ Size varies (e.g., 26", 27.5", 700c).​

⚙️ Drivetrain
●​ Crankset, chain, cassette, derailleur​

●​ Converts pedaling motion into wheel rotation.​

●​ Gears help in climbing or gaining speed.​

🛑 Brakes
●​ Rim brakes: Simple and lightweight​

●​ Disc brakes: Better in wet/muddy conditions​

🚲 Handlebars
●​ Flat, drop, or riser bars for different ride styles.​

🪑 Saddle
●​ Varies for comfort or performance.​
 ●​ Adjustable height and tilt.​

🔄 Pedals
●​ Flat: For casual use​

●​ Clipless: Attach to special cycling shoes for efficiency​

4. 🚴 Types of Bicycles
🚵 Mountain Bikes (MTB)
●​ Thick tires, suspension, rugged frames​

●​ Built for trails and rough terrain​

🛣️ Road Bikes
●​ Lightweight, thin tires, drop handlebars​

●​ Optimized for speed and distance on pavement​

🚴‍♀️ Hybrid Bikes

●​ Mix of road and mountain features​
 ●​ Great for commuting and fitness​

🚲 Cruiser Bikes
●​ Comfortable, upright posture​

●​ Stylish and casual riding​

⚡ Electric Bikes (E-bikes)

●​ Pedal-assist motors​

●​ Ideal for hills, long commutes, older riders​

🚴‍♂️ BMX and Freestyle Bikes

●​ Small, strong frames for stunts, racing, and jumps​

🛴 Folding and Cargo Bikes

●​ Space-saving or heavy load-carrying designs​

5. 💪 Benefits of Cycling
🧠 Health
 ●​ Cardiovascular fitness​

●​ Weight loss and muscle toning​

●​ Mental health boost, reduced stress​

🌍 Environment
●​ Zero emissions​

●​ Reduces traffic and noise pollution​

💸 Economic
●​ Low cost of ownership and maintenance​

●​ No fuel required​

🕒 Convenience
●​ Avoid traffic​

●​ Park easily​

●​ Ideal for short-to-medium commutes​

6. 🔧 Maintenance Tips
Task Frequency

Tire pressure Weekly

check

Chain Monthly or after

lubrication rain

Brake pad Monthly

check

Gear tuning Every few

months

Full service Yearly

Always keep your bike clean, especially after off-road rides or rain.

7. 🧠 Bike Safety and Gear

Essential Safety Items:

●​ Helmet (always wear it)​

●​ Lights & Reflectors (front and rear)​

●​ Bell or horn​
 ●​ Gloves and padded shorts​

●​ Bright or reflective clothing​

Riding Tips:

●​ Follow traffic rules​

●​ Ride in bike lanes where available​

●​ Use hand signals for turning​

●​ Keep a safe distance from vehicles​

8. 🌐 Smart and Electric Bikes (Modern Trends)

🚴 Electric Bikes (E-Bikes)
●​ Battery-powered motor assists pedaling​

●​ Speeds typically up to 25–28 mph​

●​ Growing in popularity for commuting​

📱 Smart Features
 ●​ GPS tracking​

●​ App-controlled gear shifting​

●​ Theft detection and anti-theft locks​

●​ Built-in lights and fitness tracking​

9. 🌍 Bicycles Around the World

●​ Netherlands: Biking is a primary transport; cities built for bikes.​

●​ Denmark: Copenhagen has more bikes than cars.​

●​ China & India: Bikes remain vital for millions.​

●​ USA: Urban cycling growing rapidly.​

10. 🔮 Future of Bicycles

●​ Hydrogen-powered bikes​

●​ Self-balancing smart bikes​

 ●​ AI route planning​

●​ Eco-material frames (bamboo, recycled plastic)​

●​ Integration with public transport networks​

🚲 Fun Facts
●​ Bicycles are the most efficient form of human transport (calories per
distance).​

●​ The energy equivalent of 1 liter of gasoline can power a bike for over 600
km.​

●​ There are more bicycles than cars on Earth.​

●​ The longest tandem bicycle seated 35 riders.

A bicycle, also called a pedal cycle, bike, push-bike or cycle, is a human-powered

or motor-assisted, pedal-driven, single-track vehicle, with two wheels attached to
a frame, one behind the other. A bicycle rider is called a cyclist, or bicyclist.

Bicycles were introduced in the 19th century in Europe. By the early 21st century
[1][2]
there were more than 1 billion bicycles. There are many more bicycles than
[3][4][5]
cars. Bicycles are the principal means of transport in many regions. They

also provide a popular form of recreation, and have been adapted for use as
children's toys. Bicycles are used for fitness, military and police applications,
courier services, bicycle racing, and artistic cycling.

The basic shape and configuration of a typical upright or "safety" bicycle, has
changed little since the first chain-driven model was developed around
[6][7][8]
1885. However, many details have been improved, especially since the

advent of modern materials and computer-aided design. These have allowed for a
proliferation of specialized designs for many types of cycling. In the 21st century,
electric bicycles have become popular.

The bicycle's invention has had an enormous effect on society, both in terms of
culture and of advancing modern industrial methods. Several components that
played a key role in the development of the automobile were initially invented for
use in the bicycle, including ball bearings, pneumatic tires, chain-driven
[9]
sprockets, and tension-spoked wheels.

Etymology
The word bicycle first appeared in English print in The Daily News in 1868, to
describe "Bysicles and trysicles" on the "Champs Elysées and Bois de
[10]
Boulogne". The word was first used in 1847 in a French publication to describe
[10]
an unidentified two-wheeled vehicle, possibly a carriage. The design of the

bicycle was an advance on the velocipede, although the words were used with
[10][11]
some degree of overlap for a time.

[12] [13] [14]

Other words for bicycle include "bike", "pushbike", "pedal cycle", or
[15]
"cycle". In Unicode, the code point for "bicycle" is 0x1F6B2. The entity

🚲 in HTML produces 🚲. [16]

Although bike and cycle are used interchangeably to refer mostly to two types of
two-wheelers, the terms still vary across the world. In India, for example, a
[17]
cycle refers only to a two-wheeler using pedal power whereas the term bike is

used to describe a two-wheeler using internal combustion engine or electric

motors as a source of motive power instead of motorcycle/motorbike.

History
Main article: History of the bicycle

[18]
The "dandy horse", also called Draisienne or Laufmaschine ("running

machine"), was the first human means of transport to use only two wheels in
tandem and was invented by the German Baron Karl von Drais. It is regarded as
[19][20][21][22]
the first bicycle and von Drais is seen as the "father of the bicycle",
[23][24][25][26]
but it did not have pedals. Von Drais introduced it to the public in
[27][28]
Mannheim in 1817 and in Paris in 1818. Its rider sat astride a wooden frame

supported by two in-line wheels and pushed the vehicle along with his or her feet
[27]
while steering the front wheel.

The first mechanically propelled, two-wheeled vehicle may have been built by
Kirkpatrick MacMillan, a Scottish blacksmith, in 1839, although the claim is often
[29]
disputed. He is also associated with the first recorded instance of a cycling

traffic offense, when a Glasgow 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
[30]
shillings (equivalent to £30 in 2023).

In the early 1860s, Frenchmen Pierre Michaux and Pierre Lallement took bicycle
design in a new direction by adding a mechanical crank drive with pedals on an
enlarged front wheel (the velocipede). This was the first in mass production.
Another French inventor named 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
Thomas McCall in 1869. In that same year, bicycle wheels with wire spokes were
[31]
patented by Eugène Meyer of Paris. The French vélocipède, made of iron and

wood, developed into the "penny-farthing" (historically known as an "ordinary

[32]
bicycle", a retronym, since there was then no other kind). 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 weight
distribution. In 1868 Rowley Turner, a sales agent of the Coventry Sewing
Machine Company (which soon became the Coventry Machinists Company),
brought a Michaux cycle to Coventry, England. His uncle, Josiah Turner, and
business partner James Starley, used this as a basis for the 'Coventry Model' in
[33]
what became Britain's first cycle factory.

The dwarf ordinary addressed some of these faults by reducing the front wheel
diameter and setting the seat further back. This, in turn, required
gearing—effected in a variety of ways—to efficiently use pedal power. Having to
both pedal and steer via the front wheel remained a problem. Englishman J.K.
Starley (nephew of James Starley), J.H. Lawson, and Shergold solved this
problem by introducing the chain drive (originated by the unsuccessful
[34]
"bicyclette" of Englishman Henry Lawson), connecting the frame-mounted

cranks to the rear wheel. These models were known as safety bicycles, 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
[35]
1885 Rover, manufactured in Coventry is usually described as the first
 [36]
recognizably modern bicycle. Soon the seat tube was added which created the

modern bike's double-triangle diamond frame.

Further innovations increased comfort and ushered in a second bicycle craze, the
1890s Golden Age of Bicycles. In 1888, Scotsman John Boyd Dunlop introduced
the first practical pneumatic tire, which soon became universal. Willie Hume
demonstrated the supremacy of Dunlop's tyres in 1889, winning the tyre's
[37][38]
first-ever races in Ireland and then England. Soon after, the rear freewheel

was developed, enabling the rider to coast. This refinement led to the 1890s
[39]
invention of coaster brakes. Dérailleur gears and hand-operated Bowden

cable-pull brakes were also developed during these years, but were only slowly
adopted by casual riders.

The Svea Velocipede with vertical pedal arrangement and locking hubs was
introduced in 1892 by the Swedish engineers Fredrik Ljungström and Birger
Ljungström. It attracted attention at the World Fair and was produced in a few
thousand units.

In the 1870s many cycling clubs flourished. They were popular in a time when
there were no cars on the market and the principal mode of transportation was
horse-drawn vehicles. Among the earliest clubs was The Bicycle Touring Club,
which has operated since 1878. By the turn of the century, cycling clubs
flourished on both sides of the Atlantic, and touring and racing became widely
popular. The Raleigh Bicycle Company was founded in Nottingham, England in
1888. It became the biggest bicycle manufacturing company in the world, making
[40]
over two million bikes per year.

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
 [8]
devices. More than 1 billion bicycles have been manufactured worldwide as of
[1][2]
the early 21st century. Bicycles are the most common vehicle of any kind in

the world, and the most numerous model of any kind of vehicle, whether
human-powered or motor vehicle, is the Chinese Flying Pigeon, with numbers
[1]
exceeding 500 million. The next most numerous vehicle, the Honda Super Cub
[41]
motorcycle, has more than 100 million units made, while most produced car,
[3][4][5][42]
the Toyota Corolla, has reached 44 million and counting.

​
●​

Women on bicycles on unpaved road, US, late 19th century

●​ ​

​
A penny-farthing or ordinary bicycle photographed in the Škoda Auto
museum in the Czech Republic
●​ ​

​
The Svea Velocipede by Fredrik Ljungström and Birger Ljungström, exhibited
at the Swedish National Museum of Science and Technology
●​ ​

​
Bicycle in Plymouth, England, at the start of the 20th century
●​ ​

​
Brazilian princes (from left) Antônio, Luís, and Pedro on a triple tandem
bicycle during their exile, 1891
●​ ​

​
Man with a bicycle in Glengarry County, Ontario between 1895 and 1910
●​ ​

​
The first bicycle by Baron Karl von Drais
●​ ​

​
Drawing from an 1896 newspaper of The London Hansom Cycle
●​ ​

​
Wooden draisine (around 1820), the first two-wheeler and as such the
archetype of the bicycle
●​ ​

​
Michaux's son on a velocipede 1868
●​ ​

​
Cyclists' Touring Club sign on display at the National Museum of Scotland
●​ ​

​
John Boyd Dunlop on a bicycle c. 1915
 ●​ ​

​
1886 Rover safety bicycle at the British Motor Museum. The first modern
bicycle, it featured a rear-wheel-drive, chain-driven cycle with two
similar-sized wheels. Dunlop's pneumatic tire was added to the bicycle in
1888.

Uses
[43]
Bicycles are used for transportation, bicycle commuting, and utility cycling.

They are also used professionally by mail carriers, paramedics, police,

messengers, and general delivery services. Military uses of bicycles include
communications, reconnaissance, troop movement, supply of provisions, and
[44]
patrol, such as in bicycle infantries.

They are also used for recreational purposes, including bicycle touring, mountain
biking, physical fitness, and play. Bicycle sports include racing, BMX racing,
track racing, criterium, roller racing, sportives and time trials. Major multi-stage
professional events are the Giro d'Italia, the Tour de France, the Vuelta a España,
the Tour de Pologne, and the Volta a Portugal. They are also used for
entertainment and pleasure in other ways, such as in organised mass rides,
artistic cycling and freestyle BMX.

Technical aspects
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 Firefighter bicycle

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
[45]
types, improved bicycle safety, and riding comfort.

Types
Main article: List of bicycle types

A man riding an electric bicycle

Bicycles can be categorized in many different ways: by function, by number of

riders, by general construction, by gearing or by means of propulsion. The more
common types include utility bicycles, mountain bicycles, racing bicycles,
touring bicycles, hybrid bicycles, cruiser bicycles, and BMX bikes. Less common
are tandems, low riders, tall bikes, fixed gear, folding models, amphibious
bicycles, cargo bikes, recumbents and electric bicycles.

Unicycles, tricycles and quadracycles are not strictly bicycles, as they have
respectively one, three and four wheels, but are often referred to informally as
"bikes" or "cycles".

Dynamics
Main article: Bicycle and motorcycle dynamics

A cyclist leaning in a turn

A bicycle stays upright while moving forward by being steered so as to keep its
[46]
center of mass over the wheels. This steering is usually provided by the rider,
[47]
but under certain conditions may be provided by the bicycle itself.

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
countersteering, which can be performed by the rider turning the handlebars
[48] [49]
directly with the hands or indirectly by leaning the bicycle.
Short-wheelbase or tall bicycles, when braking, can generate enough stopping
[50]
force at the front wheel to flip longitudinally. 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 stoppie, endo, or front wheelie.

Performance
Main article: 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
[51]
terms of energy a person must expend to travel a given distance. 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
[52][53]
reduce this by 10–15%. 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 16–24 km/h

(10–15 mph) uses only the power 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 aerodynamically streamlined position. Drag can also be reduced
by covering the bicycle with an aerodynamic fairing. The fastest recorded
[54]
unpaced speed on a flat surface is 144.18 km/h (89.59 mph).

In addition, the carbon dioxide generated in the production and transportation of

1
the food required by the bicyclist, per mile traveled, is less than ⁄10 that
[55]
generated by energy efficient motorcars.
 ​
●​

A recumbent bicycle
●​ ​

​
Balance bicycle for young children

Parts
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Frame
Main article: Bicycle frame

The great majority of modern bicycles have a frame with upright seating that
[6][7][8]
looks much like the first chain-driven bike. These upright bicycles almost

always feature the diamond frame, a truss 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 headset, the set of
bearings that allows the fork 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 bottom bracket. The rear triangle consists of the
seat tube and paired chain stays and seat stays. The chain stays run parallel to
the chain, connecting the bottom bracket to the rear dropout, 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.

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.
This design, referred to as a step-through frame 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 mixte, 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
[56]
the older practice of riding horse sidesaddle.

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
[57]
Union Cycliste Internationale.

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. By the
1980s aluminum welding techniques had improved to the point that aluminum
tube could safely be used in place of steel. Since then aluminum alloy frames and
other components have become popular due to their light weight, and most
[where?]
mid-range bikes are now principally aluminum alloy of some kind. More

expensive bikes use carbon fibre due to its significantly lighter weight and
profiling ability, allowing designers to make a bike both stiff and compliant by
manipulating the lay-up. Virtually all professional racing bicycles now use carbon
fibre frames, as they have the best strength to weight ratio. A typical modern
carbon fiber frame can weigh less than 1 kilogram (2.2 lb).

Other exotic frame materials include titanium and advanced alloys. Bamboo, a
[58]
natural composite material with high strength-to-weight ratio and stiffness has
[59]
been used for bicycles since 1894. Recent versions use bamboo for the

primary frame with glued metal connections and parts, priced as exotic
[59][60][61]
models.

​
●​

Diagram of a bicycle
●​ ​

​
A Triumph with a step-through frame
 ●​ ​

​
A carbon fiber Trek Y-Foil from the late 1990s

Drivetrain and gearing

Main article: Bicycle drivetrain systems

The drivetrain begins with pedals which rotate the cranks, 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
cadence, a variable gear ratio 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 to select a ratio. A dérailleur system normally has two dérailleurs,
or mechs, one at the front to select the chainring and another at the back to
select the sprocket. Most bikes have two or three chainrings, and from 5 to 12
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.
An alternative to chaindrive is to use a synchronous belt. These are toothed and
work much the same as a chain—popular with commuters and long distance
cyclists they require little maintenance. They cannot be shifted across a cassette
of sprockets, and are used either as single speed or with a hub gear.

Different gears and ranges of gears 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.

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) (cassette or
freewheel). There are four gearing options: two-speed hub gear integrated with
chain ring, up to 3 chain rings, up to 12 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).

●​ ​
A bicycle with shaft drive instead of a chain
 ●​ ​

​
A set of rear sprockets (also known as a cassette) and a derailleur
●​ ​

​
Hub gear

Steering

Bicycle grips made of leather. Anatomic shape distributes weight over palm area to
[62]
prevent cyclist's palsy (ulnar syndrome).

The handlebars connect to the stem that connects to the fork that connects to the
front wheel, and the whole assembly connects to the bike and rotates about the
steering axis via the headset bearings. 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 backward and centimeters rise upwards, as well as wider
widths which can provide better handling due to increased leverage against the
wheel.

Seating

A Selle San Marco saddle designed for women

Saddles 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 and sit bone width measurements, although bikes typically
are sold with saddles most appropriate for men. Suspension seat posts and seat
springs provide comfort by absorbing shock but can add to the overall weight of
the bicycle.

A recumbent bicycle has a reclined chair-like seat 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 steering.

Brakes
Main article: Bicycle brake

Linear-pull brake, also known by the Shimano trademark: V-Brake, on rear wheel of a
mountain bike

Bicycle brakes may be rim brakes, in which friction pads are compressed against
the wheel rims; hub brakes, where the mechanism is contained within the wheel
hub, or disc brakes, where pads act on a rotor attached to the hub. Most road
[63]
bicycles use rim brakes, but some use disc brakes. Disc brakes are more

common for mountain bikes, tandems and recumbent bicycles than on other
types of bicycles, due to their increased power, coupled with an increased weight
[64]
and complexity.

A front disc brake, mounted to the fork and hub

With hand-operated brakes, force is applied to brake levers mounted on the

handlebars and transmitted via Bowden cables or hydraulic 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.

Track bicycles 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
[65]
a conventional rear wheel brake, but not as effective as a front wheel brake.

Suspension
Main article: 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.

Wheels and tires

Main articles: Bicycle wheel and 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. Road bicycles use
tires 18 to 25 millimeters wide, most often completely smooth, or slick, and
inflated to high pressure to roll fast on smooth surfaces. Off-road tires are usually
between 38 and 64 mm (1.5 and 2.5 in) wide, and have treads for gripping in
muddy conditions or metal studs for ice.

Groupset
Groupset generally refers to all of the components that make up a bicycle
excluding the bicycle frame, fork, stem, wheels, tires, and rider contact points,
such as the saddle and handlebars.

Accessories

Touring bicycle equipped with front and rear racks, fenders (called mud-guards), water
bottles in cages, four panniers and a handlebar bag

Some components, which are often optional accessories on sports bicycles, are
standard features on utility bicycles to enhance their usefulness, comfort, safety
and visibility. Fenders with spoilers (mudflaps) protect the cyclist and moving
parts from spray when riding through wet areas. In some countries (e.g. Germany,
UK), fenders are called mudguards. The chainguards protect clothes from oil on
the chain while preventing clothing from being caught between the chain and
crankset teeth. Kick stands keep bicycles upright when parked, and bike locks
deter theft. Front-mounted baskets, front or rear luggage carriers or racks, and
panniers mounted above either or both wheels can be used to carry equipment or
cargo. Pegs can be fastened to one, or both of the wheel hubs to either help the
rider perform certain tricks, or allow a place for extra riders to stand, or
[citation needed]
rest. Parents sometimes add rear-mounted child seats, an auxiliary

saddle fitted to the crossbar, or both to transport children. Bicycles can also be
fitted with a hitch to tow a trailer for carrying cargo, a child, or both.
Toe-clips and toestraps and clipless pedals help keep the foot locked in the
proper pedal position and enable cyclists to pull and push the pedals. Technical
accessories include cyclocomputers for measuring speed, distance, heart rate,
GPS data etc. Other accessories include lights, reflectors, mirrors, racks, trailers,
[66]
bags, water bottles and cages, and bell. Bicycle lights, reflectors, and helmets

are required by law in some geographic regions depending on the legal code. It is
more common to see bicycles with bottle generators, dynamos, lights, fenders,
racks and bells in Europe. Bicyclists also have specialized form fitting and high
visibility clothing.

Children's bicycles may be outfitted with cosmetic enhancements such as bike

[67]
horns, streamers, and spoke beads. Training wheels are sometimes used when

learning to ride, but a dedicated balance bike teaches independent riding more
[68][69]
effectively.

Bicycle helmets can reduce injury in the event of a collision or accident, and a
[70][71]
suitable helmet is legally required of riders in many jurisdictions. Helmets
[66] [72]
may be classified as an accessory or as an item of clothing.

Bike trainers are used to enable cyclists to cycle while the bike remains
stationary. They are frequently used to warm up before races or indoors when
[73]
riding conditions are unfavorable.

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 International Organization for Standardization (ISO) has a special technical

committee for cycles, TC149, that has the scope of "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 European Committee for Standardization (CEN) also has a specific Technical
Committee, TC333, that defines European standards for cycles. Their mandate
states that EN cycle standards shall harmonize with ISO standards. 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
[note 1]
harmonized parts geometry.

Maintenance and repair

Like all devices with mechanical moving parts, bicycles require a certain amount
of regular maintenance and replacement of worn parts. A bicycle is relatively
simple compared with a car, so some cyclists choose to do at least part of the
maintenance themselves. Some components are easy to handle using relatively
simple tools, while other components may require specialist
manufacturer-dependent tools.

Many bicycle components are available at several different price/quality points;

manufacturers generally try to keep all components on any particular bike at
about the same quality level, though at the very cheap end of the market there
may be some skimping on less obvious components (e.g. bottom bracket).

●​ There are several hundred assisted-service Community Bicycle

[74]
Organizations worldwide. At a Community Bicycle Organization,

laypeople bring in bicycles needing repair or maintenance; volunteers

teach them how to do the required steps.
●​ Full service is available from bicycle mechanics at a local bike shop.
 ●​ In areas where it is available, some cyclists purchase roadside
assistance from companies such as the Better World Club or the
American Automobile Association.

Maintenance

The most basic maintenance item is keeping the tires correctly inflated; this can
make a noticeable difference as to how the bike feels to ride. Bicycle tires usually
have a marking on the sidewall indicating the pressure appropriate for that tire.
Bicycles use much higher pressures than cars: car tires are normally in the range
of 30 to 40 pounds per square inch (210 to 280 kPa), whereas bicycle tires are
normally in the range of 60 to 100 pounds per square inch (410 to 690 kPa).

Another basic maintenance item is regular lubrication of the chain and pivot
points for derailleurs and brake components. Most of the bearings on a modern
bike are sealed and grease-filled and require little or no attention; such bearings
will usually last for 10,000 miles (16,000 km) or more. The crank bearings require
periodic maintenance, which involves removing, cleaning and repacking with the
correct grease.

The chain and the brake blocks are the components which wear out most quickly,
so these need to be checked from time to time, typically every 500 miles (800 km)
or so. Most local bike shops will do such checks for free. Note that when a chain
becomes badly worn it will also wear out the rear cogs/cassette and eventually
the chain ring(s), so replacing a chain when only moderately worn will prolong
the life of other components.

Over the longer term, tires do wear out, after 2,000 to 5,000 miles (3,200 to 8,000
km); a rash of punctures is often the most visible sign of a worn tire.