1. Keep fit
Bicycle is one of the best tools to overcome heart problems. More than half of the world's people die of heart disease. Cycling can not only compress the blood flow by the movement of the legs, and draw the blood back to the heart from the end of the blood vessels, but also strengthen the microvascular tissue, which is called "accessory circulation". Strengthened blood vessels can protect you from the threat of age and keep you young forever.
In addition, habitual cycling can gradually expand your heart. Otherwise, the blood vessels will become thinner and thinner, and the heart will become more and more degenerated. In your later years, you will experience the troubles it brings. At that time, you will find how perfect cycling is.
Cycling is a sport that requires a lot of oxygen. There was an old man who completed a 460km bicycle trip in 6 days. He said: "The elderly should exercise at least three times a week to strengthen the heart and restore its normal function. You should make the heart beat violently, but not too long. In this way, it will be able to adapt to emergency situations, such as driving or resisting difficulties."
Cycling can also prevent high blood pressure, sometimes more effective than drugs. It can also prevent obesity, hardening of blood vessels, and make bones strong. Bicycles make it unnecessary for you to use drugs to maintain your health, and they do no harm.
Bicycle is a tool to lose weight. According to statistics, a person with a weight of 75kg can reduce his weight by half a kilogram when riding 73 miles at a speed of 9 and a half miles per hour, but he must persevere every day.
Cycling can not only reduce weight, but also make your figure more symmetrical and charming. That is, people who exercise to lose weight or exercise while dieting are better and more attractive than those who only diet to lose weight.
Proper exercise can secrete a hormone, which makes you cheerful and happy. From experience, we know that cycling can produce this hormone.
In fact, because cycling compresses blood vessels, speeding up blood circulation, and the brain takes in more oxygen, you breathe in more fresh air. After riding for a while, you will feel clearer.
Riding this kind of two wheeled bicycle with your own strength, you will feel very free and very happy. It is not only a weight loss exercise, but also an exile of spiritual pleasure.
2. Sports
Cycling is a sport that uses bicycles as tools to race the speed of riding. In 1896, the first Olympic Games was listed as an official event. In 1900, the International Cycling Union was established, and since then, it has successively held the World Cycling Championships (once a year), the World Peace Cycling Race (a multi day race with a total length of more than 2000 kilometers around Berlin, Warsaw and Prague), and the Tour de France (a multi day race with a total length of 3966 kilometers around France).
Chinese cycling was introduced from Europe around 1913. At that time, bicycles were mainly used as vehicles. In 1930, Pan Deming cycled around the world and returned to China after more than seven years through more than 40 countries and regions, including Vietnam, Cambodia, Thailand, Australia, Indonesia, Malaysia, Singapore, the United States, Canada, Cuba and Sweden.
After 1940, various forms of small and medium-sized bicycle races were held in the track and field in various parts of China. In 1947, China held its first national exhibition competition in Shanghai. After the founding of the People's Republic of China, cycling has developed comprehensively and rapidly.
In 2002, China held the Qinghai Lake Cycling Race for the first time, and by 2007, it had held 6 sessions.
1) Maximum speed
The maximum speed of bicycle is 268.831 km/h, which was created by Fred Romberg of the Netherlands in Bonneville Salt Beach, Utah, on October 3, 1995. The achievement of this record is largely due to the low-pressure cavitation generated by his pilot car. The normal alternative riding is 15 kilometers per hour.
2) Materials used
Chrome molybdenum steel frame: Before the 1990s, the bicycle frame was mainly made of chrome molybdenum steel. It has good torsion and tensile properties, and the high temperature during welding will not affect the material, so it is cheap. But it is heavy and easy to be oxidized.
Carbon fiber frame: It is light, can absorb the impact of the ground, and has fast reverse force. It is an ideal material for bicycle frame. The higher the tonnage, the higher the elasticity and the higher the price of carbon fiber. There are several manufacturing methods, such as sticking adhesive on the mold, overlapping carbon fibers, heat treatment, solidification, molding, etc.
Titanium frame: Titanium is 55% lighter than steel and is not easy to oxidize. In order to improve the tensile strength, there are titanium alloys mixed with aluminum, vanadium, etc. Welding in vacuum is complicated, and the frame is expensive.
Aluminum frame: The frame made of aluminum alloy is light and rigid. The weight of a specially processed frame is only 1kg. Aluminum pipes tend to be large-diameter. In order to ease the excessive rigidity, carbon fiber with strong impact absorption force is adopted for the seat pipe and fork.
