Bakelite

Other activists, especially those from the more established tradition, view the safety, practicality, and intent of many segregated cycle facilities with suspicion. Controversially, some bicycle activists (including some traffic management advisors) seek the construction of segregated cycle facilities for journeys of all lengths. Many cities also have community bicycle programs that promote cycling, especially as a means of inner-city transport. Activists in both camps also argue for improved local and inter-city rail services and other methods of mass transportation, and also for greater provision for cycle carriage on such services.

Such groups promote the bicycle as an alternative mode of transport and emphasize the potential for energy and resource conservation and health benefits gained from cycling versus automobile use. Two broad themes run in bicycle activism: one more overtly political with roots in the environmental movement; the other drawing on the traditions of the established bicycle lobby. Cyclists form associations, both for specific interests (trails development, road maintenance, urban design, racing clubs, touring clubs, etc.) and for more global goals (energy conservation, pollution reduction, promotion of fitness). Studies have demonstrated that, due to the high incidence of accidents at these sites, such segregated schemes can actually increase the number of car-bike collisions.⁷.

At some point the two streams of traffic inevitably intersect, often in a haphazard and congested fashion. Segregating bicycle and automobile traffic in cities has met with mixed success, both in terms of safety and bicycle promotion. Such dedicated paths often have to be shared with inline skaters, scooters, skateboarders, and pedestrians. Extensive bicycle path systems may be found in some cities.

Conversely, an absence of secure cycle-parking is a recurring complaint by cyclists from cities with low modal share of cycling. Local governments also promote cycling by permitting the carriage of bicycles on public transport or by providing external attachment devices on public transport vehicles. In areas in which cycling is popular and encouraged, cycle-parking facilities using bicycle racks, lockable mini-garages, and patrolled cycle parks are used to reduce theft. In Shanghai, a city where bicycles were once the dominant mode of transportation, bicycle travel on city roads was actually banned temporarily in December 2003.

Occasionally, extreme measures against cycling may occur. In the former cases, cycling has tended to decline while in the latter it has tended to be maintained. Other cities may apply active traffic restraint measures to limit the impact of motorised transport. Some jurisdictions give priority to motorised traffic, for example setting up extensive one-way street systems, free-right turns, high capacity roundabouts, and slip roads.

Cyclists and motorists make different demands on road design which may lead to conflicts both in politics and on the streets. monocoque frames, such as used by Chris Boardman to win the Gold medal in 1992 Olympic individual pursuit event in Barcelona, were no longer permitted. For example. Their stated motive was so that developing countries could compete in international competitions without requiring large equipment budgets, and to re-focus attention on the athlete rather than the bicyle.

These rules met with considerable controversy and to some extent arrested the development of the racing bicycle. The governing body of international cycle sport, the Union Cycliste International, decided in the late 1990s to create additional rules restricting the design of racing bicycles. In the past decade, mountain bike racing has also reached international popularity and is even an Olympic sport. Track bicycles are used for track racing in Velodromes , while cyclo-cross races are held on rugged outdoor terrain.

Recumbent bicycles were banned from bike races in 1934 after Marcel Berthet set a new hour record in his Velodyne streamliner (49.992 km on Nov 18, 1933). They range from the one-day road race, criterium, and time trial to multi-stage events like the Tour de France and its sister events which make up cycling's Grand Tours. Road races may involve both team and individual competition, and are contested in various ways. As the bicycle evolved its various forms, different racing formats developed.

This began in 1903, and continues to capture the attention of the sporting world. The most famous of all bicycle races is the Tour de France. However since the middle of the 20th Century cycling has become a minority sport in the US whilst in Continental Europe it continues to be a major sport, particulrly in France, Belgium and Italy. At one point, almost every major city in the US had a velodrome or two for track racing events.

and Japan as well. Large races became popular during the 1890's "Golden Age of Cycling", with events across Europe, and in the U.S. Early races involving boneshaker style bicycles were predictably fraught with injuries. Shortly after the introduction of bicycles, competitions developed independently in many parts of the world.

The only country to recently maintain a regiment of bicycle troops was Switzerland, who disbanded the last unit in 2003. invasion of Afghanistan and in subsequent battles against the Taliban. Special Forces in the U.S. There are reports of mountain bicycles being used in scouting by U.S.

In the Vietnam War, communist forces used bicycles extensively as cargo carriers along the Ho Chi Minh Trail. Germany used bicycles again in World War II, while the British employed airborne Cycle-commandos with folding bikes. In its 1937 invasion of China, Japan employed some 50,000 bicycle troops, and similar forces were instrumental in Japan's march through Malaya in World War II. In World War I, France and Germany used bicycles to move troops.

Bicycles were used in the Second Boer War, where both sides used them for scouting. The bicycle is not suited for combat, but it has been used as a method of transporting soldiers and supplies to combat zones. Paris-Brest-Paris (PBP), which began in 1891, is the oldest bicycling event still run on a regular basis on the open road, covers over 1200 km and imposes a 90-hour time limit. Many Dutch people subscribe every year to an event called fietsvierdaagse — four days of organised cycling through the local environment.

The land is very flat and full of special public bicycle trails where cyclist aren't bothered by cars and other traffic, which makes it ideal for cycling recreation. One major aspect of Dutch popular culture is enjoying relaxed cycling in the countryside of the Netherlands. A brevet or randonnée is an organized long-distance ride. Bicycle touring involves touring and exploration or sightseeing with the use of a bicycle for leisure.

Bicycles are used for recreation at all ages. At the huge Mercedes-Benz factory in Sindelfingen, Germany workers use bicycles, colour-coded by department, to move around the factory. Even the car industry uses bicycles. In Bogotá, Colombia the city’s largest bakery recently replaced most of its delivery trucks with bicycles.

In India, many of Mumbai's Dabbawalas use bicycles to deliver hot lunches to the city’s workers. In the UK, this use persisted for some purposes with generations of teenagers getting their first jobs delivering newspapers by bicycle. Bicycles have enjoyed substantial use as general delivery vehicles in many cities. The pursuit of suspects can also be assisted by a bicycle.

They also have the advantages that the officers are inherently more open to the public, and the transport is quieter to permit a more stealthy approach toward suspects. Bicycle patrols are now enjoying a resurgence in many cities, as the mobility of car-borne officers is becoming increasingly limited by traffic congestion and pedestrianisation. Some countries retained the police bicycle while others dispensed with them for a time. The Kent police purchased 20 bicycles in 1896, and by 1904 there were 129 police bicycle patrols operating.

However, they eventually became a standard issue, particularly for police in rural areas. Police officers adopted the bicycle as well, initially using their own. Bicycle delivery fleets include 37,000 in the UK, 25,700 in Germany and 10,500 in Hungary. The Royal Mail first started using bicycles in 1880.

The postal services of many countries have long relied on bicycles. One of the major reasons for the proliferation of Chinese-made bicycles in foreign markets is the increasing affordability of cars and motorcycles for its own citizens ⁵. Despite this shift in production, as nations such as China and India become more wealthy, their own use of bicycles has declined. Some sixty percent of the world's bicycles are now being made in China.

In recent years, US and European bicycle makers have moved much of their production to Asia. Both their model for political organization and the paved roads for which they argued facilitated the growth of the bicycle's rival, the automobile. In North America, the political organization of bicycle enthusiasts, in such groups as the League of American Wheelmen, led to further changes. They also reduced dependence on horses, and allowed people to travel into the country, since bicycles were three times as energy efficient as walking, and three to four times as fast.

In cities, bicycles helped reduce crowding in inner-city tenements by allowing workers to commute from single-family dwellings in the suburbs. Sociologists suggest that bicycles enlarged the gene pool for rural workers, by enabling them to easily reach the next town and increase their courting radius. The diamond-frame safety bicycle gave women unprecedented mobility, contributing to their emancipation in Western nations. A British perfumer marketed Cycling Bouquet, which came in a tiny vial designed to fit into a lady cyclist's purse.

In the 1890s the cycling craze led to a new set of fashions, including bloomers, which helped liberate women from corsets and other restrictive clothing. The evolution of the bicycle had less tangible effects as well, extending early to areas as diverse as fashion and politics. In the United States, the League of American Wheelmen was a prominent advocate for the improvement of roads in the last part of the 19th century, founding and leading the national Good Roads Movement in the US. Some bicycle clubs and national associations became prominent advocates for improvements to roads and highways.

The Morris Motor Company and Škoda also began in the bicycle business, as did Henry Ford and the Wright Brothers. Starley's company became the Rover Cycle Company Ltd. in the late 1890s, and then the Rover auto maker. K. J.

These techniques later enabled skilled metalworkers and mechanics to develop the components used in early automobiles and aircraft. Building modern bicycle frames led to the development of advanced metalworking techniques, both for the frames themselves and for special components such as ball bearings, washers, and sprockets. Bicycle manufacturing proved to be a training ground for other industries. For more information on the technical aspects of bicycles, see also:.

Speed changes, making the bicycle/motorcycle stiffer or lighter, or increasing the stiffness of the steering (of which the rider is the main component) can change the oscillation frequency, though only speed change is applicable in the situation. If there is insufficient damping in the steering the oscillation will increase until system failure. The restoring force is applied in phase with the progress of the irregularity, and the wheel turns to the other side where the process is repeated. Some otherwise minor irregularity accelerates the wheel to one side.

This shimmy is often seen in shopping cart front wheels. While the wobbles can be easily remedied by slowing down, adjusting position, or relaxing one's grip on the handlebars, speed wobbles can be fatal. At higher speeds bicycles can also experience speed wobbles or shimmies, where the front wheel spontaneously oscillates to the left and right. [1] [2].

Positive trail - found on typical bicycles - creates positive stability by steering the contact patch back under the CG of the bicycle and rider. Zero trail (as in a unicycle) requires constant rider adjustment. Negative trail (rolling a bicycle backwards) results in immediate steering problems. The moment due to trail and the weight of the bicycle will turn the front wheel in the direction of the turn.

One can see the effect that trail has by simply holding a bicycle by the seat and leaning it. The greater the amount of trail, the greater the reaction. This is the distance between the point of contact the front wheel makes with the ground and the place the steering axis makes contact with the ground. Stability is also influenced by a geometric factor called trail.

Jones found he could ride this bike with no difficulty, but did discover that without a rider the non-gyroscopic bike fell over much faster than a regular bike. By gearing this wheel to the regular front wheel so that it spun in the opposite direction at equal speed, the net angular momentum of both wheels together was close to zero. Jones, whose series of "URBs" ("unrideable bikes" with various modifications to the front end) included a bike which cancelled the gyroscopic effect of the front wheel by dint of attaching a second wheel to his front forks (alongside the regular wheel) whose lower edge was about an inch (25 mm) above the ground. H.

That gyroscopic effects are unimportant at normal cycling speeds was shown by physicist and researcher into bicycle stability David E. Conversely, a bicycle whose steering fork is locked in a perfectly straight ahead position is virtually impossible to balance. These forces, perhaps aided at very high speeds by the gyroscopic effect of the spinning wheels,⁴ are sufficiently strong that a riderless bicycle going down a slope will stay upright by itself. Like the rider's steering adjustments, this motion automatically returns the contact point of the wheel directly under the center of gravity.

Once underway, this effort is largely replaced by physical forces generated by the rotation of the wheels which produce a remarkable "self-steering" effect.³ The angular momentum of the wheels and the torque applied to them by the ground generates a phenomenon called precession, by which the wheel turns, or trails, toward whichever side the bicycle tilts. A rider stays upright on a bicycle by steering the bicycle so that the point where the wheels touch the ground stays underneath the center of gravity. These changes can impact performance dramatically, cutting minutes off a time trial. For this reason more recent designs have concentrated on lowering wind resistance, using aerodynamically shaped tubing, flat spokes on the wheels, and handlebars that allow the rider to bend over into the wind.

For instance, lowering a bike's weight by 1 kg, a major effort considering they may weigh less than 15 kg to start with, will have the same effect over a 40 km time trial as removing a protrusion into the air the size of a pencil. In measured tests these components have almost no effect on cycling performance. Additionally, advanced wheels are available with low-friction bearings and other features to lower road resistance. There has been major corporate competition to lower the weight of racing bikes through the use of advanced materials and components.

This stands as the official record for all human-powered vehicles. The highest speed ever officially attained on the flat, without using motor pacing and wind-blocks, is by Canadian Sam Whittingham, who in 2002 set a 130.36 km/h (81.00 mph) record on his highly aerodynamic recumbent bicycle. On a fast racing bicycle, a reasonably fit rider can ride at 50 km/h (30 mph) on flat ground for short periods. Typical speeds for bicycles are 16 to 32 km/h (10 to 20 mph).

Even at moderate speeds, most cycling energy is spent in overcoming aerodynamic drag, which increases with the square of speed; therefore, power needs increase approximately with the cube of speed. Elite track sprinters are able to attain an instantaneous maximum output of around 2,000 watts, or in excess of 25 watts/kg; elite road cyclists may produce 1,600 to 1,700 watts as an instantaneous maximum in their burst to the finish line at the end of a five-hour long road race. The average "in-shape" man can produce about 3 watts/kg for more than an hour (e.g., around 200 watts for a 70 kg rider), with top amateurs producing 5 watts/kg and elite athletes achieving 6 watts/kg for similar lengths of time. However, because of its efficiency, cycling requires a longer distance, and often greater time, than running to consume the same amount of energy.

For many people whose running might be limited by muscle and knee pain, cycling offers comparable outdoor exercise that can be enjoyed by people of a wide range of fitness levels: it is a "no-impact" sport that is easy on the body as long as the bike is properly "fit." In addition, since bicycling can also provide convenient transportation, less self-discipline may be required to keep to the activity, since it has a practical purpose. Generally used figures are. That same man on a bicycle, on the same ground, with the same power output, can average 25 km/h, so energy expenditure in terms of kcal/kg/km is roughly one-fifth as much. On firm, flat, ground, a 70 kg man requires about 100 watts to walk at 5 km/h.

A bicycle in which the rider lies in a prone position and which may be covered in an aerodynamic fairing to achieve very low air drag is referred to as a Recumbent_bicycle or Human Powered Vehicle. Air drag, which increases with the square of speed, requires increasingly higher power outputs relative to speed. A human being travelling on a bicycle at low to medium speeds of around 10-15 mph (16-24 kph), using only the energy required to walk, is the most energy-efficient means of transport generally available. In terms of the ratio of cargo weight a bicycle can carry to total weight, it is also a most efficient means of cargo transportation.

In terms of the amount of energy a person must expend to travel a given distance, investigators have calculated it to be the most efficient self-powered means of transportation.¹ 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% ^{2 9}. In both biological and mechanical terms, the bicycle is extraordinarily efficient. Others maintain their own bicycles, enhancing their enjoyment of the hobby of cycling. Some bicycle parts, particularly hub-based gearing systems, are complex, and many prefer to leave maintenance and repairs to professionals.

More specialised parts now require more complex tools, including proprietary tools specific for a given manufacturer. A single tool once sufficed for most repairs. Many cyclists carry tool kits, containing at least a tire patch kit, tire levers, and spanners. No correlation between decreased injury rates and helmet use has been demonstrated in whole populations.

Outside the West, use of helmets by utility cyclists is practically unknown. In Australia and New Zealand, and parts of Canada, helmets are required by law. federal law requires helmets, many states require children to wear them, and some municipalities require them for all riders. While no U.S.

In North America a significant minority, possibly up to 25% of bicyclists, wear helmets. In most countries where cycling is common, bicycle helmet use is negligible. Toe-clips help to keep the foot planted firmly on the pedals, and enable the cyclist to pull as well as push the pedals. Technical accessories include solid-state speedometers and odometers for measuring distance.

Other accessories include lights, pump, lock, and additional (pedal or wheel-mounted) reflectors. Parents sometimes add rear-mounted child seats and/or an auxiliary saddle fitted to the crossbar to transport children. Rear racks or carriers can be used to carry items such as school satchels. Front-mounted wicker or steel baskets for carrying goods are often used.

Kick stands help with parking. Chainguards and mudguards, or fenders, protect clothes and moving parts from oil and spray. Utility bicycles have many standard features which enhance their usefulness and comfort that would be considered accessories on sports bicycles. For these reasons, one must weigh the advantages and disadvantages of using a hydraulic system versus a mechanical system.

This is due to the brake losing its ability to transmit force through incompressible fluids, since some of it has become a gas, which is compressible. Also, the hydraulic fluid may boil on steep, continuous downhills. However, since hydraulic disc brakes usually require relatively specialized tools to bleed the brake systems, repairs on the trail are difficult to perform, whereas mechanical disc brakes rarely fail. Hydraulic disc brake systems generally keep contaminants out better.

Mechanical disc brakes have less modulation than hydraulic disc brake systems, and since the cable is usually open to the outside, mechanical disc brakes tend to pick up small bits of dirt and grit in the cable lines when ridden in harsh terrain. Two main disc brake systems exist: hydraulic and mechanical (cable-actuated). The use of tires as large as 3.0 inches in width also makes disc brakes a necessity, as rim brakes simply cannot straddle a tire that wide. The advantages of discs make them well-suited to steep, extended downhills through wet and muddy off-road terrain, which falls under the category of downhill and freeride bicycle riding.

In the late 1990s, disc brakes appeared on some off-road bicycles, tandems and recumbent bicycles, but are considered impractical on road bicycles, which rarely encounter conditions where the advantages of discs are significant. With hand-operated brakes, force is applied to brake handles mounted on the handle bars and then transmitted via Bowden cables to the friction pads. Hub drum brakes do not cope well with extended braking, so rim brakes are favoured in hilly terrain. A rear hub brake may be either hand-operated or pedal-actuated, as in the back pedal coaster brakes which were the rule in North America until the 1960s.

Bicycle brakes are either rim brakes, in which friction pads are compressed against the wheel rims, internal hub brakes, in which the friction pads are contained within the wheel hubs, or disc brakes. The reclined, low seating position does provide increased aerodynamics over standard seating. Recumbent bicycles have more chair-like seats, and so are much more comfortable to ride, although generally slower up hills due to this positioning. For racing bikes where the rider is bent over, weight is more evenly distributed between the handlebars and saddle, and the hips are flexed, and a narrower and harder saddle is more efficient.

With comfort bikes and hybrids the cyclist sits high over the seat, their weight directed down onto the saddle, such that a wider and more cushioned saddle is preferable. Comfort depends on riding position. Seats, or saddles, also vary with rider preference, from the cushioned ones favoured by short-distance riders to narrower seats which allow more free leg swings. The Bullhhorn was banned from ordinary road racing because it is considered there is less fine control in bike traffic.

These are usually used in conjunction with the aero bar, a pair of forward-facing extensions spaced close together, to promote better aerodynamics. Bullhorn style handlebars are often seen on modern time trial bicycles, equipped with two forward-facing extensions, allowing a rider to rest his entire forearm on the bar. Variations on these styles exist. Mountain bikes feature a crosswise handlebar, which helps prevent the rider from pitching over the front in case of sudden deceleration.

Racing handlebars are "dropped", offering the cyclist either an aerodynamic "hunched" position or a more upright posture in which the hands grip the brake lever mounts. Touring handlebars, the norm in Europe and elsewhere until the 1970s, curve gently back toward the rider, offering a natural grip and comfortable upright position. Three styles of handlebar are common. The handlebars rotate the fork and the front wheel via the stem, which articulates with the headset.

Retro-Direct drivetrains used on some early 20th century bicycles have been resurrected by bicycle hobbyists. This also results in increased wear because of the lateral deflection of the chain. Derailleur efficiency is also compromised with cross-chaining, or running large-ring to large-cog or small-ring to small-cog. Efficiency generally decreases with smaller cog sizes because the chain must bend more sharply as it rolls on and off the cog, and it also forms a sharp angle at the chain tensioner⁹.

In derailleur mechanisms the highest efficiency is achieved by the larger cogs. Derailleur type mechanisms fare better, with a typical mid-range product (of the sort used by serious amateurs) achieving between 88% and 99% efficiency at 100W. Which ratios are best and worst depends on the specific model of hub gear. In a typical hub gear mechanism the mechanical efficiency will be between 82% and 92% depending on the ratio selected.

The efficiency varies considerably with the gear ratio being used. While generally variable ratio gear mechanisms are essential for human efficiency, they do reduce mechanical efficiency. Fixed-gear track racing bikes have transmission efficiencies of over 99% (nearly all the energy put in at the pedals ends up at the wheel). Mountain bikes and most entry-level road racing bikes may offer an extremely low gear to facilitate climbing slowly on steep hills.

Road bicycles have close set multi-step gearing, which allows very fine control of cadence, while utility cycles offer fewer, more widely spaced speeds. Internal hub gearing still predominates in some regions, particularly on utility bikes, whereas in other regions, such as the USA, external derailleur systems predominate. However, they may be heavier and/or more expensive, and often do not offer the same range or number of gears. Internal hub gears are much less affected by adverse weather conditions than derailleurs, and often last longer and require less maintenance.

The gear systems are hand-operated, via cables (or rarely, hydraulics), and are of two types. Since cyclists' legs produce a limited amount of power most efficiently over a narrow range of cadences, a variable gear ratio is needed to maintain an optimum pedaling speed while covering varied terrain. Between the chain and rear wheel may be interspersed various gearing systems, described below, which vary the number of rear wheel revolutions produced by each turn of the pedals. Attached to the crank is the chainring which drives the chain, which in turn rotates the rear wheel via the rear sprockets.

The drivetrain begins with pedals which rotate the crankset, which fit into the bottom bracket. More expensive carbon fibre and titanium frames are now also available, as well as advanced steel alloys. In the 1980s aluminium alloy frames became popular, and their affordability now makes them common. Celluloid found application in mudguards, and aluminium alloys are increasingly used in components such as handlebars, seat stems (also known as seatposts), and brake levers.

Since the late 1930s alloy steels have been used for frame and fork tubes in higher quality machines. Historically, materials used in bicycles have followed a similar pattern as in aircraft, the goal being strength and low weight. Although some women's bicycles continue to use this frame style, there is also a hybrid form, the mixte or step-through frame, which also allows easier mounting and dismounting for both male and female riders. This allowed the rider to dismount while wearing a skirt or dress.

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. The seat stays connect the top of the seat tube (often at or near the same point as the top tube) to the rear dropouts. The chain stays run parallel to the chain, connecting the bottom bracket to the rear dropouts. The rear triangle consists of the seat tube and paired chain stays and seat stays.

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 head tube contains the headset, the interface with the fork. The front triangle consists of the head tube, top tube, down tube and seat tube. Nearly all modern upright bicycles feature the diamond frame, composed of two triangles: the front triangle and the rear triangle.

Since a moving bicycle makes very little noise, in many countries bicycles must have a warning bell for use when approaching pedestrians, equestrians and other bicyclists. As some generator or dynamo-driven lamps only operate while moving, rear reflectors are frequently also mandatory. In some places, bicycles must have functioning front and rear lights or lamps. In many jurisdictions it is an offence to use a bicycle that is not in roadworthy condition and which does not have functioning front and rear brakes.

The traffic codes of many countries reflect these definitions and demand that a bicycle satisfy certain legal requirements, including licencing, before it can be used on public roads. The 1968 Vienna Convention on Road Traffic considers a bicycle to be a vehicle, and a person controlling a bicycle is considered a driver.
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Manufacturers responded with the hybrid bicycle, which restored many of the features long enjoyed by riders of the time-tested European utility bikes. These task-specific designs led many American recreational cyclists to demand a more comfortable and practical product. In the late 1980s the mountain bike became particularly popular, and in the 1990s something of a major fad. By the 1980s these newer designs had driven the three-speed bicycle from the roads.

While 10-speeds were the rage in the 1970s, 12-speed designs were introduced in the 1980s, and today most bikes feature 18 or more speeds. Sales were also helped by a number of technical innovations that were new to the US market, including higher performance steel alloys and gearsets with an increasing number of gears. Bicycle sales in the United States boomed, largely in the form of the racing bicycles long used in such events as the hugely popular Tour de France. In North America, increasing consciousness of physical fitness and environmental preservation spawned a renaissance of bicycling in the late 1960s.

Especially in Amsterdam they are often colourfully painted and/or otherwise decorated. In the Netherlands, such so-called 'granny bikes' have remained popular, and are again in production. In other parts of the world however, such as China, India, and European countries such as Germany, Denmark, and the Netherlands, the traditional utility bicycle remained a mainstay of transportation, its design only gradually changing to incorporate hand-operated brakes and internal hub gears allowing up to seven speeds. In North America, bicycle sales declined markedly after 1905, to the point where by the 1940s, they had largely been relegated to the role of children's toys.

In many western countries the use of bicycles levelled off or declined, as motorized transportation became affordable and car-centred policies led to an increasingly hostile road environment for bicycles. By the mid-20th century bicycles had become the primary means of transportation for millions of people around the globe. Facilitated by connections between European nations and their overseas colonies, European-style bicycles were soon available worldwide. Schwinn bicycles soon featured widened tires and spring-cushioned, padded seats, sacrificing some efficiency for increased comfort.

Schwinn emigrated to the United States, where he founded his similarly successful company in Chicago in 1895. Bowden started the Raleigh company in Nottingham in the 1890s, and soon was producing some 30,000 bicycles a year. Successful early bicycle manufacturers included Englishman Frank Bowden and German builder Ignaz Schwinn. By the turn of the century, bicycling clubs flourished on both sides of the Atlantic, and touring and racing were soon the rage.

Derailleur gears and hand-operated, cable-pull brakes were also developed during these years, but were only slowly adopted by casual riders. This refinement led to the 1898 invention of coaster brakes. Shortly thereafter the rear freewheel was developed, enabling the rider to coast without the pedals spinning out of control. In 1888 Scotsman John Boyd Dunlop introduced the pneumatic tire, which soon became universal.

The next innovations increased comfort and ushered in the 1890s Golden Age of Bicycles.
While the Starley design was much safer, the return to smaller wheels made for a bumpy ride. Soon the seat tube was added, creating the double-triangle, diamond frame of the modern bike. Starley's 1885 Rover is usually described as the first recognizably modern bicycle.

These models were known as dwarf safeties, or safety bicycles, for their lower seat height and better weight distribution. Lawson, and Shergold solved this problem by introducing the chain and producing rear-wheel drive. H. Starley, J.

K. Starley's nephew, J. Having to both pedal and steer via the front wheel remained a problem. The subsequent dwarf ordinary addressed some of these faults, by adding gearing, reducing the front wheel diameter, and setting the seat further back with no loss of speed.

The primitive bicycles of this generation were difficult to ride, and the high seat and poor weight distribution made for dangerous falls. British cyclists likened the disparity in size of the two wheels to their coinage, nicknaming it the penny-farthing. With tires of solid rubber, his machine became known as the ordinary. He mounted the seat more squarely over the pedals, so that the rider could push more firmly, and further enlarged the front wheel to increase the potential for speed.

The Boneshaker was further refined by James Starley in the 1870s. Lallement emigrated to America, where he recorded a patent on his bicycle in 1866 in New Haven, Connecticut. Their creation, which came to be called the "Boneshaker", featured a heavy steel frame on which they mounted wooden wheels with iron tires. In the 1850s and 1860s, Frenchman Ernest Michaux and his pupil Pierre Lallement took bicycle design in a different direction, placing pedals on an enlarged front wheel.

However, some reports describe MacMillan's vehicle as more of a "quadricycle". Scottish blacksmith Kirkpatrick MacMillan shares creative credit with von Drais for adding a treadle drive mechanism, in 1840, that enabled the rider to lift his feet off the ground while driving the rear wheel. These were pushbikes, powered by the action of the rider's feet pushing against the ground. He patented his draisine, a number of which still exist, including one at the Paleis het Loo museum in Apeldoorn, the Netherlands.

The most likely originator of the bicycle is German Baron Karl von Drais, who rode his 1817 machine while collecting taxes from his tenants. Most bicycle historians now believe that these hobby-horses with no steering mechanism probably never existed, but were made up by Louis Baudry de Saunier, a 19th-century French bicycle historian. One of these, the scooter-like dandy horse of the French Comte de Sivrac, dating to 1790, was long cited as the earliest bicycle. Its earliest known forebears were called velocipedes, and included many types of human-powered vehicles.

No single time or person can be identified with the invention of the bicycle. . A recurrent theme in bicycling has been the tension between bicyclists and drivers of motor vehicles, each group arguing for its fair share of the world's roadways. Beyond recreation and transportation, bicycles have been adapted for use in many occupations, including the military, local policing, courier services, and sports.

In its early years, bicycle construction drew on pre-existing technologies; more recently, bicycle technology has contributed, in turn, to other, newer areas. The bicycle has affected history considerably in both the cultural and industrial realms. as a child's toy, in adult recreation and fitness, as a means of everyday transport, in cyclo-touring, as a basis of cycle sport (branches: track, off-road or MTB, downhill, cyclo-cross, time trialling, road racing, cycle speedway, cycle polo, BMX), and as a basis for static gymnasium or home fitness versions. A remarkable aspect of the bicycle is its widespread adoption in many different fields of human activity, e.g.

The basic shape and configuration of the frame, wheels, pedals, saddle and handlebars has hardly changed since the first chain-driven model was developed around 1885, although many important detail improvements have been made since, especially in recent years using modern materials and computer-aided design. The bicycle is one of the most notable of human inventions. Numbering over 1,000,000,000 in the world today, bicycles provide the principal means of transportation in many regions and a popular form of recreational transport in others. First introduced in 19th-century Europe, bicycles evolved quickly into their familiar, current design.

A bicycle, or bike, is a pedal-driven land vehicle with two wheels attached to a frame, one behind the other. ISO 4210 Cycles — Safety requirements for bicycles. ISO 8090 Cycles — Terminology (same as BS 6102-4). ISO 5775 Bicycle tire and rim designations.

A unicycle is not a bicycle, as it has only one wheel, but it is related. Art bikes: Some bikes are built so that the frame appears to be made of junk or found objects: Bongo the Clown built several ridable parade bikes which were as much kinetic sculptures as transport. Come-apart bike, (essentially a unicycle, plus a set of handlebars attached to forks and a wheel). tall bike (often called an upside down bike, constructed so that the pedals, seat and handlebars are all higher than normal) -- other types tall bikes are made by welding two more more bicycle frames on top of each other, and running additional chains from the pedals to the rear wheel.

bucking bike (with one or more eccentric wheels). Some types of clown bicycles are: