A bicycle, or a bicycle (abbreviation of the word velocipede), is a human-powered land vehicle falling into the category of cycles and composed of two in-line wheels, which give it its name. The driving force is provided by its driver (called a “cyclist”), most often in a seated position, by means of two pedals driving the rear wheel by a roller chain.
The front wheel is steerable and ensures balance. Its orientation is controlled by a handlebar. The cyclist often has both hands in contact with the handlebars in order to control the trajectory, the braking as well as the change of gears.
The bicycle is one of the main means of transportation in many parts of the world. Its energy efficiency is particularly high. Its practice, cycling, is at the same time a daily use of transport, a popular leisure activity and a sport.
In 1817, the German baron Karl Drais von Sauerbronn invented his Laufmaschine or “running machine” which was presented in Paris on April 5, 1818 (French import patent filed by Louis-Joseph Dineur in the name of Baron Drais on February 17, 1818: under the name of a “Machine known as a velocipede.”) 1.
The balance bike (version 1817) has two in-line wheels, connected to a wooden frame by forks, the front wheel being able to pivot sideways, and it is equipped with a rudimentary shoe brake on the rear wheel. This machine has had some success, in particular in France and then in the United Kingdom. In this country, he will be called "hobby-horse".
The first attested visual design of a bicycle-type two-wheeler is due to Alexandre Mercier. It appears in his patent of May 8, 1843. The pedaling is alternative, like the Lévoyclettes Terrot of the 1910s. It is also the first convincing example of sustained balance on two wheels, while on the balance bike, the equilibrium is only temporary. In his patent, Mercier says he tried his machine successfully in Amiens, but this is not proven.
If the balance bike is part of the prehistory of the bicycle, the real story begins in France with pedal velocipeds during the 1860s. It was around 1867 that the first pedal velocipeds from the houses of Sargent, Michaux, Vincent, etc. were marketed. ., with real popular success. Pierre Michaux, a Parisian locksmith in a custom car, is said to have invented the pedal velocipede in 1855. The precise date of the invention and the identity of the inventor are however much debated. In 1893, during a controversy with the brothers André and Aimé Olivier, former partners who have always denied Michaux's role in the invention, Henry Michaux, son of Pierre Michaux, admits that it would be his brother Ernest who would have had the idea of the pedals, and that the invention would in fact date from 18612. This date is however questioned by certain historians, who give 1864 as a more plausible date, and also cast doubts on the paternity of the invention of the family Michaux3. It is true that we have no proof to date. At the same time, another Frenchman, Pierre Lallement, claimed to have invented and experimented with a pedal system in 1862, and in 1866 obtained an American patent for a machine he called “bicycle” 4. About ten other inventors claim this invention. The most plausible today, although also without proof, is Georges Radisson.
Pierre Michaux only filed in 1868 a patent for his invention, which he called “pedivelle” (French patent no. 80637 filed April 24, 1868: “Perfectionnement dans la construction des vélocipèdes.”), To which he also added a brake. From the fall of 1867, the velocipede was enormously successful in France, and the first velocipede races, clubs and newspapers appeared.
Pierre Lallement emigrated to the United States in 1865 without having been able to find financial support in Paris for his machine, and obtained the world's first patent on the pedal velocipede in November 1866. He succeeded in selling his patent to a New Yorker, Calvin Witty, who will be the first to manufacture two-wheelers in the United States (only one of these velocipeds seems to have survived) and returns to France in 18685. At the end of that year, Witty selling his license to other manufacturers , success also occurs in the United States. Some nicknamed the machine boneshaker ("bone shaker"), because of the design of the wheels, made of wood, rimmed with iron. The first hard rubber wheel linings appeared in 1869 and significantly improved the comfort of the machine.
In 1869, Charles Desnos filed a patent on the improvement of the velocipede which fixed certain characteristics still present in modern bicycles, in particular the rear driving wheel and the multiplier transmission by belt or chain7.
After the war of 1870, the improvement of velocipeds continued especially in England. The front wheel gets bigger while the rear wheel gets smaller. The first grand-bi, called Ordinary, appeared in 1872. This type of bicycle was extremely popular with the bourgeoisie, who alone had the means to afford it. In England, it is nicknamed penny farthing (after the respective size of these two coins, by analogy with the wheels). In France, it is used ostentatiously by the bourgeoisie (example: culture of pleasure and elegance in the Bois de Boulogne) 8.
The first bicycle patent was filed in 1871 by Viarengo de Forville, an Italian living in France9. In his French patent of September 30, 1871, photos of a man's and a woman's bicycle are attached.
In 1884 John Kemp Starley of The Coventry Sewing Machine Company, which later became Rover, invented the “safety bicycle” with reasonably sized wheels and chain drive. . The cyclist is installed there at the rear, which makes it almost impossible to fall like a “sun” where the cyclist is catapulted over the front wheel10. A larger gear at the front (the chainring) than at the rear (the pinion) turns the rear wheel faster than the pedals turn, allowing this type of machine to go fast even without a giant wheel.
In 1886, Peugeot marketed its first bicycles. In 1885, the Bordelais Juzan built a few as well, with a more modern design than the English ones.
In 1888, John Boyd Dunlop invented the tire (French patent No. 193281 filed by John Boyd Dunlop on October 1, 1888: “Rim lining applicable to vehicle wheels.”), Which further improved the comfort of the cyclist. Édouard Michelin perfected this invention by filing in 1891 a patent for a “removable tire”, the inner tube.
Safety bicycles from 1890 already look a lot like bicycles today. They have tires comparable in size to a modern bicycle, wire wheels, a tubular steel frame and chain drive. The only thing they lack is the gear change.
In the 1890s, this new model of bicycle broadened the target of potential users. In addition, in connection with the second industrial revolution, bicycles became an industrial product (in France, the major brands were then Peugeot in the Doubs, Manufrance in Saint-Étienne, Mercier in the Loire), reducing their price to a point that makes them affordable to workers. This leads to a “bicycle madness” 11, which is at the origin of an important social evolution (passage from the leisure bicycle to the utility bicycle).
From this period, the bicycle is essential as a means of discovering the world. As the world tour fashion developed, the first cycling tour took place between 1891 and 189412. The first woman to achieve this solo feat was Annie Cohen Kopchovsky, known as Annie Londonderry, on a branded male model bicycle. Sterling, in fifteen months13.
In this regard, the development of the bicycle has allowed the progress of the emancipation of women, even if access to the bicycle for the latter has been strewn with pitfalls. The feminist Susan B. Anthony declared in 1896 that the device had accomplished more for this liberation than anything else in the world. Despite Annie Londonderry's round-the-world cycle tour in 1895, some doctors and moralists persisted in claiming that the bicycle posed a threat to the physical and mental health of women. In addition, it would encourage shamelessness and exhibitionism15. For example, it was thought that riding a saddle and moving in this position could lead women to develop masturbatory practices, which were absolutely immoral at the time. In fact, nineteenth-century women's clothing was absolutely not suitable for sports, the wearing of trousers being reserved for men16. The women then fought to wear the bloomer, a kind of feminine shorts, in order to be able to practice the bicycle. As early as 1868, some competitions were nevertheless open to women. In a premonitory way, Jacques Mauprat declares in Le Progrès of April 21, 1895: “Yes, the weak woman has proven herself on the bicycle. She achieved very satisfactory performances; and this not only without prejudice to his health […]. This introduction of women into the world of sport is a revelation for her and will almost be the source of a revolution in the mores of society, starting with the costume and ending with the regeneration of many qualities lost by the muscle inactivity. "
In 1903 the Tour de France was born. The first winner of this great event is Maurice Garin.
After the First World War, the term “bicycle” became the popular word to describe the bicycle used by workers, peasants and children8.
In the 1930s, multi-speed systems began to be used in cycling competitions.
The vélocar appears in the 1930s, recumbent bicycle and ancestor of the velomobile.
During the occupation of France by Germany, cars were restricted to the use of doctors, the police or the militia, the bicycle becoming the queen of transport (supplies and the black market, trips to work or to go seeing relatives, development of bicycle taxis in large cities), success in cycling competitions17.
Derailleurs developed during the 1950s.
Finally, velomobiles were reborn at the end of the 1980s.
Since the beginning of the 1990s, in several countries, spontaneous demonstrations have brought together, once a month in several hundred towns, defenders and promoters of the use of cycling in towns. These are the critical masses or velorution in France.
On March 28, 2017, in a public note18, the think tank La fabrique écologique estimates that the Interministerial Coordination for the Development of the Use of Cycling (Ciduv) is "endowed with low human and budgetary resources" and "cannot ensure the steering of an ambitious national strategy ”. France lacks understanding of the brakes on cycling. The bicycle kilometer allowance (IKV) is struggling to develop and the Ademe devotes few resources to cycling. Responsibility for cycling is delegated at the local level (by the NOTRe law) to communities where the “public transport” culture dominates, lacking a “strong national impetus”. The think tank proposes the bases for a national bicycle strategy in order to make up for the 20–25 years of delay acquired in Northern Europe, advocating the creation of an interministerial bicycle mission (MIV) and the consideration of the bicycle no longer as a a leisure activity but as an “instrument of transport policy” 19.
In fact, in France, according to an INSEE study for 2015, only 2% of working people go to work by bicycle. The bicycle is mainly used when the workplace is up to 4 km from home. This mode of transport is generally much less used than the automobile, which is largely predominant, public transport or walking, but it is on a par with motorized two-wheelers20. In the city, however, as in Paris, bicycle trips represent a third of those made by car21
The bicycle has only two points of support on the ground: it is necessarily in unstable equilibrium. Physicists speak of a metastable equilibrium because the passage from the position of temporary equilibrium to a position of perceptible imbalance is relatively slow.
The main forces in action are:
gravity, which tends to pull the bike towards the ground;
centrifugal force, which when the bike turns, tends to straighten it out of the turn.
The balance is maintained dynamically by the actions of the rider, who always endeavors to straighten his machine by tilting it slightly in the direction opposite to that in which it begins to fall.
The cyclist therefore constantly juggles between these two forces to compensate for the effects of one with the other. It is helped in this by the trail of the bicycle: it is the distance between the intersection of the axis of the fork with the ground and the point of contact of the front wheel with the ground. Indeed, the axis of the fork is inclined so that its intersection with the ground is in front of the point of contact of the wheel with the ground. Thus, if the bicycle is tilted to one side, the front wheel is forced to position so as to rotate the bicycle on the same side, thereby initiating a turn tending to balance that tilt.
Finally, when the bicycle is rolling, the gyroscopic effect linked to the rotation of the wheels thwarts any variation in the position of their axes. This phenomenon is proportional to the speed of rotation of the wheels and to their mass. This effect is usually negligible and is normally imperceptible to the cyclist. Indeed, the mass and therefore the inertia of the bicycle and its rider are an order of magnitude greater than that of the wheels, which considerably reduces the influence of the gyroscopic effect.
The frame is the main part, it usually consists of a triangle on which the rider's weight is distributed from the fulcrum of the saddle, associated with a second smaller triangle on which the rear wheel is mounted: this second triangle is made up of shrouds (outer edge of the rear triangle) and chainstays (base of the rear triangle). The front wheel is fixed to the frame by a fork, the upper part of it is mounted on ball bearings through an almost vertical tube at the front of the frame. These ball bearings constitute the headset. The top of the fork forms a stem to which the handlebars are attached. The fork can be suspended. Many modern bicycle models are also designed without fixed seatstays, replaced by a suspended system. This system can take various and varied forms, from the use of joints based on bearings, to the use of flexible materials (titanium in particular) which allow progressive deformation. Such "full suspension" bikes are designed for riding on uneven terrain such as mountain biking to provide additional comfort.
The energy is supplied by the cyclist through his feet, with which he presses on the pedals, connected to one or more gears at the level of the crankset: the chainring (s). The rear gear, the pinion (but there are often several pinions of different sizes attached together, this is called a cassette) is mounted on the rear wheel by a non-return ratchet mechanism: the freewheel. The transmission of movement between a chainring and a pinion is provided by the chain. Depending on the type of practice for which the bike is designed, the cassette can be "flat" as often on a road bike, which means that between two successive sprockets, there is only one more tooth. on the largest; on other types of bikes such as mountain bikes, the number of teeth can increase much faster between successive sprockets. The set of elements included between the pedals and the rear wheel is referred to by the term transmission.
One of the most important parts of a bicycle is the braking system. It is made up of two independent brake handles, each controlling a jaw which applies rubber buffers to the rim via brake cables. The cables are mostly protected in sheaths. Certain braking systems, for more performance, are based on the principle of the disc brake, or the drum brake, integrated into the hub.
Since the 1950s, most brake systems have been derived from the side-pull shoe design invented by Campagnolo. The two arms of the jaw tighten when the cable, attached to the end of one of the arms and passing through the end of the other, is stretched. The pressure of the pads applied by the rim is balanced thanks to a spring which distributes the force between the two jaw arms.
The increasingly frequent use of larger tires on mountain bikes ended up posing a problem: the rim and its tire became too wide to fit between the brake shoes. Initially, the cantilever system provided an answer to this problem. The jaw arms became independent, while being connected by a short braking force distribution cable. The control cable is then fixed in the middle of the distribution cable. However, this system has some weaknesses: if the fixing of the control cable is not centered, the force is poorly distributed between the arms, and if the connector becomes unhooked, the distribution cable can block the wheel suddenly by getting stuck in tire designs, which can lead to an accident if it happens on the front wheel.
A more suitable solution to the problem of tire width is the v-brake. The cable is fixed in such a way that it is directed upwards so that it cannot fall back on the tire, and also transmits the braking power delivered by the brake lever much better, while being a little easier to handle. center during assembly.
Tires and rims
The wheels are fitted with pneumatic tires, or tires, in order to increase the comfort of the cyclist, and to reduce the stresses undergone by the mechanics.
The tires can be attached to the rims in two ways: either glued (we speak of tubulars), or mounted on a notch which goes around each side of the rim (conventional tires). The width and the tread patterns of the tires are adapted according to the use of the bike: thin and smooth for the road, thicker and with numerous studs for mountain biking, etc.
In North America and other areas where the ground freezes during winter, it is possible to install tires with metal spikes. These provide greater grip on icy surfaces and enthusiasts of this means of transport can thus circulate throughout the winter.
Signaling equipment is mainly composed of active lighting and reflectors or reflectors.
The lighting consists of a white lamp towards the front, a red one towards the rear, most often supplied by an alternator, often incorrectly called a "dynamo".
Reflectors intended to supplement the visibility of the cyclist can be installed. For lateral visibility, these may be orange reflectors which are fixed between the spokes of the wheels, or white reflective strips painted on the tires or inserted between the spokes right up against the rim. For visibility from the front and from the rear, the sidelamps are normally lined with reflectors of the same color and the pedals are fitted with orange reflectors.
Finally, bicycles generally have a bell activated on the handlebars, which clearly distinguishes them from motor vehicle warning devices.
The mandatory systems in France are listed on the website of the French Ministry of the Interior28