Bicycle

• 1. Introduction

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  By the early 21st century, more than 1 billion bicycles existed in the world. The bicycle was invented in Europe in the 19th century, and its basic shape has barely changed since the first chain-driven model appeared around 1885. Yet hidden inside that simple frame are ideas that reshaped how people lived, worked, and moved. Several components first invented for the bicycle later made the automobile possible, including ball bearings, pneumatic tires, chain-driven sprockets, and tension-spoked wheels. How did a two-wheeled, pedal-driven vehicle become both the most efficient human-powered transport ever built and a training ground for the industrial age? Who learned to ride toward freedom on one? And why does a machine of up to a thousand parts still feel, to its rider, almost like flight?

• 2. A Word For Two Wheels

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  In 1868, The Daily News printed the word bicycle for the first time in English, describing "Bysicles and trysicles" on the "Champs Elysees and Bois de Boulogne". The word had surfaced earlier, in 1828, when French used it for a two-wheeled chaise, a horse-drawn carriage. For a time the new term overlapped with velocipede, the design the bicycle improved upon. The vehicle answers to many names. People call it a bike, a pushbike, a pedal cycle, or simply a cycle. The rider is a cyclist or bicyclist. The machine even has its own symbol: in Unicode, the code point U+1F6B2 produces a small bicycle character. That tidy designation marks how thoroughly the object entered everyday language.

• 3. The Most Efficient Machine

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  Up to 99% of the energy a rider delivers into the pedals reaches the wheels, making the bicycle extraordinarily efficient in mechanical terms. Gearing mechanisms may trim that figure by 10-15%, and a small amount of tire slip occurs, but the core transfer remains remarkable. The bicycle is the most efficient human-powered means of transportation for the energy spent to cover a given distance, when moving slowly or fitted with an aerodynamic fairing. A person riding at low to medium speeds of roughly 16 to 24 km/h uses only the power required to walk. Air drag grows with the square of speed, so faster riding demands dramatically more power. A rider sitting upright creates about 75% of the total drag of the bicycle and rider combined. Streamlining the position, or covering the machine with a fairing, cuts that resistance. The extremes show what is possible. The fastest recorded unpaced speed on a flat surface with a standing start came from the hour record in 2016: over 92 km/h, roughly 57 mph, on a highly streamlined bicycle.

• 4. Anatomy Of A Frame

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  One bicycle may have up to a thousand parts, and the heart of it is the frame. Most modern bicycles use a diamond frame, a truss built from two triangles. The front triangle joins the top tube, down tube, and seat tube, with the head tube holding the headset bearings that let the fork turn for steering. The rear triangle pairs chain stays and seat stays that meet at the dropouts, where the rear axle sits. Women's bicycle frames historically connected the top tube to the middle of the seat tube rather than the top. This step-through or open frame lowered the standover height and let a rider mount and dismount in a dignified way while wearing a skirt or dress, though it placed a bending load on the seat tube where frames are typically weak. The mixte splits the top tube into two thinner tubes that bypass the seat tube on each side. Materials have chased high strength and low weight, much as in aircraft. Alloy steels entered higher quality machines since the late 1930s. By the 1980s, improved welding let aluminum tube replace steel, and aluminum alloy now dominates mid-range bikes. More expensive machines turn to titanium or carbon fibre laid up in resin, which lets designers make a frame both stiff and compliant. A typical modern carbon fibre frame can weigh less than 1 kg. Bamboo, a natural composite with high strength-to-weight ratio, has been used since 1894.

• 5. Gears, Brakes, And Balance

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  Cyclists' legs work most efficiently over a narrow range of pedaling speeds, or cadence, so a variable gear ratio lets a rider hold an optimum pace across changing terrain. Most bicycles use the derailleur system, which moves the chain between chainrings and sprockets to select a ratio, while some utility bikes use hub gears with between 3 and 14 ratios. Most bikes carry two or three chainrings and 5 to 12 sprockets, though many theoretical gears overlap or run the chain diagonally, leaving fewer usable. A toothed belt offers a low-maintenance alternative, popular with commuters, used as single speed or with a hub gear. Stopping has its own logic. Bicycle brakes may grip the rim, sit inside the hub, or squeeze a disc rotor attached to the hub. Most road bicycles use rim brakes, while disc brakes suit mountain bikes, tandems, and recumbents for their greater power. Back pedal coaster brakes stayed popular in North America until the 1960s. Track bicycles carry no brakes at all. Every rider circles the track in the same direction, and because all track bikes are fixed-gear with no freewheel, coasting is impossible. To slow down, a rider applies resistance to the pedals. Balance itself is a quiet feat of physics. A bicycle stays upright while moving forward by being steered to keep its center of mass over the wheels. The combined center of mass of bike and rider must lean into a turn, a lean induced by countersteering. Push the front wheel and balance there, lifting the rear, and you have a trick called a stoppie, endo, or front wheelie.

• 6. The Freedom Machine

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  On the 2nd of February 1896, in a New York World interview, Susan B. Anthony declared the bicycle had "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." The safety bicycle gave women a mobility they had never known. As bicycles grew safer and cheaper, more women reached the personal freedom the machine embodied, and it came to symbolize the New Woman of the late 19th century, especially in Britain and the United States. The 1890s bicycle craze fed a movement for so-called rational dress, helping free women from corsets and ankle-length skirts in favor of the then-shocking bloomers. Frances Willard, the tightly laced president of the Woman's Christian Temperance Union, wrote in 1895 a 75-page illustrated memoir titled A Wheel Within a Wheel: How I Learned to Ride the Bicycle, with Some Reflections by the Way. She praised her bicycle, "Gladys", for its "gladdening effect" on her health and political optimism, and used the cycling metaphor to urge fellow suffragists to action. The fit of the machine itself eventually followed. In 1985, Georgena Terry started the first women-specific bicycle company, designing frames with shorter top tubes and wheel sizes chosen to better suit women.

• 7. Engine Of Industry

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  As much as 10% of all advertising in US periodicals in 1898 came from bicycle makers. Bicycle manufacturing became a training ground for other industries, driving advanced metalworking for frames and for components such as ball bearings, washers, and sprockets. Those same techniques later let skilled metalworkers build the parts used in early automobiles and aircraft. The industry pioneered the business methods that would define the century. Albert Pope first practiced mechanization and mass production, later copied by Ford and General Motors, along with vertical integration, aggressive advertising, and lobbying for better roads, which doubled as both publicity and more places to ride. Bicycle makers also adopted the annual model change, later derided as planned obsolescence and usually credited to General Motors. Some of the era's famous names began on two wheels. Wilbur and Orville Wright ran the Wright Cycle Company, designing and selling bicycles during the bike boom of the 1890s. J. K. Starley's firm became the Rover Cycle Company Ltd. in the late 1890s, then the Rover Company once it built cars. Morris Motors Limited in Oxford and Skoda also began in the bicycle business. The trade even spawned unexpected inventions. The best known, adopted far beyond cycling, is Charles Bennett's Bike Web, which came to be called the jock strap. Production has since migrated. Over 60% of the world's bicycles are now made in China, drawn there by lower labor costs. In 2011, amid the European financial crisis, bicycle sales in Italy reached 1.75 million and surpassed new car sales.

• 8. Riding Into Daily Life

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  The first community bicycle program was the White Bicycle plan in Amsterdam in 1965, followed by yellow bicycles in La Rochelle and green bicycles in Cambridge. These bicycle sharing systems complement public transport and offer an alternative to motorized traffic, easing congestion and pollution. Around the turn of the 20th century, the bicycle had already reshaped the city, letting workers commute from more spacious suburban dwellings and reducing both inner-city crowding and dependence on horses. Bicycles were three times as energy efficient as walking and three to four times as fast, opening the countryside to leisure. Cycling culture runs deepest in particular places. In Europe, especially the Netherlands and parts of Germany and Denmark, bicycle commuting is common, and in Copenhagen a cyclists' organization runs a Cycling Embassy promoting biking for commuting and sightseeing. Every train station in the Netherlands offers free bicycle parking, and in Delft the capacity is usually exceeded. In Trondheim, Norway, the Trampe bicycle lift helps cyclists up a steep hill. In Ilhavo, Portugal, bicycle culture has been integral to the landscape for generations without much official support. The machine carries weight in the modern economy too. Foursquare, whose CEO Dennis Crowley "pedaled to pitch meetings" while raising money from venture capitalists, chose its New York headquarters "based on where biking would be easy". In 2012, Mitchell Moss of the Rudin Center for Transportation Policy and Management at New York University observed, "Biking has become the mode of choice for the educated high tech worker". The 1968 Vienna Convention on Road Traffic still counts the bicycle a vehicle, and the rider, whether pedaling or not, a driver.