Who invented the bicycle? Why can't you ride on only two wheels?

There are many stories about the invention of bicycles. China was the first country in the world to invent bicycles. The ancestor of bicycle was a unicycle in China in more than 500 BC. During the Kangxi period of Qing Dynasty (1662 ~ 1722), Huang Lvzhuang once invented bicycles. "Grand View of unofficial history in Qing Dynasty" has been published for eleven years: "Huang Lvzhuang built a two-wheeled vehicle, which is more than three feet long and can sit for one person without pushing or pulling. When walking, turn your arm around the axis, then walk as before, and walk 80 miles around the sun with your arm. " This is the earliest bicycle in the world. Bicycles were invented by western Europeans. In A.D. 1790, the Frenchman Sifrak developed a wooden bicycle without handlebars, pedals and chains. The car is shaped like a wooden horse, with two wheels nailed to its feet and fixed on a line. Because this bicycle has no driving device and steering device, and the seat cushion is low, Sifrak rides on the bicycle by himself, with his feet on the ground and pushing back hard to make the bicycle move straight forward. 18 17, the German baron von delaisse invented a handlebar that can move freely, making his bicycle easier to replace. Delaisse obtained a patent in Britain. 1839, K. Macmillan, a British worker, pioneered a pedal bicycle with a crankshaft mechanism to drive the rear wheels, so that people can leave their feet off the ground when riding a bicycle. 186 1 year, one day, Michelson, a Parisian carriage and stroller manufacturer, repaired delaisse's bicycle. After the repair, they found it difficult to put their feet on the ramp, so they improved it, and installed a pedal crankshaft on the front wheel of the car, thus inventing Michelle's bicycle, which soon began mass production. Around 1870, a Frenchman, Ma Zhi, made a bicycle with a big front driving wheel and a small rear driven wheel. This kind of bike runs well. 1890, Humber Company of England produced a diamond bicycle with chain drive, which has been in use ever since. Bicycles were invented by Russians. 180 1 One day in September, Russian serf Artamonov traveled 2,500 kilometers to Moscow to present a gift to Tsar Alexander I. The bicycle made in Artamonov was similar to that made in France by Sifrak. When Alexander I saw the bicycle made by Artamonov, he immediately ordered the abolition of his slave status. People and machines are so outstanding! A senior Turkish official praised Stevens as an "ordinary man" when he saw him get off his bike. Humans have used wheels (single wheel, two wheels, three wheels or four wheels) for about five thousand years, but before 1690, no one connected two wheels to ride. A Frenchman named De West Flach straddled a two-wheeled vehicle he called "Celeriffler" with his feet apart, put one leg aside and let it roll forward. The rolling of the wheel is limited, because he hasn't created a way to drive the machine. The drivable Dreyfus car was successfully developed by Karl von Dreyfus in 18 17. It is a mechanical bicycle, which was invented by Macmillan in 1839. The rear wheel is driven by a crank connected to the pedal. With bicycles, human beings can travel by themselves, and it is much faster than walking. However, not many people are interested in this idea. 186 1 year, a French hatter named brunell took his Dreyfus to the carriage manufacturer Misaud for repair. Mishaw's son Ernest probably didn't know Macmillan's invention at all, so he suggested that if a crank was installed on the front wheel-just like the handle of a mill-and it could be turned step by step, the machine would certainly be improved. In this way, he unexpectedly started the bicycle industry. In some bicycles called "Velocipide" in the early days, the pedal rotates once and the wheels rotate once. Before the bicycle named "Penny Fassen" was invented, the front wheel became bigger and bigger. People properly call this kind of car "high bike". It runs fast, but it is not stable: if you want to brake, especially when going downhill, the cyclist may be thrown in front of the handlebar and fall several times a day. However, people are not afraid. The sports club was established. 1884, the brave Thomas Stevens rode, pushed and sometimes even carried a tall bicycle named "Ordinary Man" across the United States. Intermittently, attempts were made to make the front wheel smaller to make the bicycle safer. However, due to the limitation of the technical level at that time, these attempts failed. Reliable bicycle chain is an important invention, without which it is impossible. 1885, stahly invented a chain-driven bicycle, which was named "Safe Roaming Vehicle", thus ending the era of high bicycles. Bicycles quickly adopted chain drive, but did not adopt his structural design. People have tried various methods to connect two wheels, trying to combine rigidity, controllability, mechanical efficiency and comfort. Driving soon became quite reliable and efficient. Deng Lupu reinvented pneumatic tires in 1888, and further developed bicycles. There seems to be no fundamental change in bicycles at present. In recent years, many people want to develop a better bicycle, but their efforts are in vain. Nowadays, bicycles spread all over the world like a flood, entering thousands of households. But few people know that bicycles were invented by a German ranger named delaisse (1785- 185 1). Delaisse used to be a forest ranger. He had to walk from one forest to another every day. Years of hard work on foot aroused his desire to invent a means of transportation. He thought: If people can sit on wheels, they will walk faster! In this way, delaisse began to design and manufacture bicycles. He made a unicycle with two wooden wheels, a saddle and a handlebar, which is connected to the front wheel for control. People sit in cars and drive wooden wheels with their feet. In this way, the world's first bicycle came out. 18 17, delaisse rode his bike for the first time and was ridiculed all the way ... He was determined to answer this ridicule with facts. In a race, he rode for 4 hours, but the horse-drawn car took 15 hours. However, no manufacturer is willing to produce and sell this kind of bicycle. 1839, Macmillan, a native of Scotland, invented the pedal and put it on the front wheel of the bicycle, which greatly improved the bicycle technology. In the following decades, various bicycles emerged, such as windsurfing bicycles, water treadmills, ice bicycles and five-wheeled bicycles, and bicycles gradually became popular means of transportation. With the emergence of pneumatic tires and chains, the structure of bicycles is becoming more and more perfect. Delaisse also invented the meat grinder and typewriter, which can reduce the labor intensity. At present, the trams that railway workers push by manpower on the tracks are also invented by delaisse, so they are called "delaisse". There are only two wheels when driving, but why can you keep balance? Even if riding a bicycle, the master can leave the handlebar with both hands and let the car go forward without worrying about falling (but worrying about the car in front whistling past). The physicist took out a gyro, put it on the ground and began to whip it hard. As the top turns faster and faster, it looks like a tumbler. Although only one pointed to the ground, it swayed from side to side and refused to fall. This is the gyro effect: the rotating object has inertia to keep its rotation direction (the direction of the rotation axis). The gyro has only one direction of rotation, and it is already very stable. This bike has two wheels. Obviously, when the bicycle wheel rotates at high speed, it will make the bicycle more stable. So the cyclist won't fall when he unfolds the handlebar. But unfortunately, this is not a reasonable explanation. Gyro effect may play an important role in maintaining the stability of bicycles, but if bicycles are stabilized only by gyro effect, beginners should not fall down when riding at high speed. However, it seems that two gyroscopes are not enough to support the rider's tens of kilograms of body tilt. When I first learned to ride a bike, I often fell badly. On the other hand, it is difficult for acrobats riding unicycle to keep their balance by gyro effect because of their slow speed or even the complete stop of their wheels. The balance of a bicycle comes from the muscles of the rider's waist first. Skilled cyclists have automatic conditioning of body shape. When the bicycle leans slightly downward, the human body will feel that the waist muscles will move automatically, pulling the body to the other side, and the resulting reverse torque will urge the body to lift. When we learn to ride a bike, we train our muscles to complete this conditioned reflex. Once we learn it, this control loop will remain in the cerebellum, which can be activated at any time and will not be forgotten for many years. But when riding a bike at high speed, you will feel that the car is more stable than when you first started. Why? The balance mechanism of the bicycle itself comes from the backward inclination of the front fork. We can observe that the handlebar axis of almost every bicycle is not completely perpendicular to the ground, but backward. Because the front wheel is fixed on the front fork of the handlebar, it is also called the front fork backward. The front fork leans backward, so that the centrifugal force generated when the vehicle turns is opposite to the direction of wheel deflection, forcing the wheel to automatically return to the original middle position after deflection. In this way, the car has the stability of automatic righting. The faster the vehicle speed, the greater the recovery torque and the more stable the rider feels. This is why when riding a bicycle at high speed, you will feel that the car is more stable than when you first started. Generally speaking, the farther back the front fork is, the more stable the car is, but the harder it is to turn the handlebar; The rear inclination is small, which makes it easier to turn the handle, but the stability of the car is not enough. But if a bicycle has no front fork at all, riding a bicycle will be a very painful thing. Bicycle is actually a rather complicated mechanical system, and the front wheel positioning of automobile is more complicated. There are kingpin tilt-in, kingpin tilt-back, front wheel camber and front wheel toe-in, which ensure that the car runs as smoothly as possible, but reduce tire wear.