Bicycle
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Introduction
Bicycle, also known as bicycle or bicycle, is a small land vehicle usually with two wheels. It is generally driven by people riding on the pedals. Bi in English bicycle means two and cycle means wheel. In mainland China, Taiwan, and Singapore, it is usually called "bicycle" or "bicycle", and in Hong Kong and Macau, it is usually called "bicycle".
Many countries and regions consider bicycles to be vehicles, and often require them to be properly equipped and even register with relevant government departments to receive a license plate before they can go on the road. Some places require bicycles to use lights when driving at night. The traffic regulations of the People's Republic of China classify bicycles as a non-motorized vehicle. In Hong Kong, bicycles are classified as "non-motorized vehicles" and do not need a license. However, when driving on the road, they must abide by the same traffic rules as motor vehicles.
History
In 1790, there was a Frenchman named Sifulak who loved to use his brain. One day, he was walking on a street in Paris. Because it had rained the day before, there was a lot of rainwater on the road, making it difficult to walk. Suddenly, a four-wheeled carriage rolled up from behind. The street was relatively narrow and the carriage was very wide. Xifulak was able to hide and avoid being hit by the car, but he was still splashed with mud and rainwater. Others saw it and felt sorry for him. They even cursed in anger and wanted to ask the carriage to stop and negotiate with him. But Xifulak murmured: "Stop shouting, stop shouting, let them go." The carriage went away, and he still stood blankly on the side of the road. He was thinking: The road is so narrow and there are so many pedestrians, why can't the structure of the carriage be changed? The carriage should be cut in half along the way, and the four wheels should become two wheels at the front and rear... When he thought about it, he thought Design at home. After repeated trials, the first "Wooden Horse Wheel" car for transportation was built in 1791. This car has two wooden wheels at the front and back, with a crossbeam in the middle and a bench on it, like a toy club. Since the car does not yet have a transmission chain, the car can only move forward slowly by the rider's feet firmly pushing on the ground. Moreover, there is no steering device on the car. It can only go straight without turning. After a while, you will be exhausted and sweating profusely after going out for a ride. .
New things that just appear are always not so perfect. Undeterred, Sifulak continued to think of ways to improve. Unfortunately, he died of illness soon.
In 1818, there was a forester named Delais in Germany. He walked from the woods to the east of the village to another woods to the west of the village every day, and he did this every year. He thought: Wouldn't it be cool if a person sat in a car and walked and walked as he pleased? Delais began to make a wooden wheel cart, which looked similar to Sifulak's. However, a direction control handle is added to the front wheel to change the direction of travel. But when riding a bicycle, you still need to use two feet to push the ground step by step to push the bike forward. When Delais went out on his bicycle to test, he was laughed at by many people along the way. Despite this, he still likes this "cute little pony" he created.
In 1840, Macmillan, a blacksmith in England, got a dilapidated "lovely pony". He installed a crank on the axle of the rear wheel, and then used a connecting rod to connect the crank to the front pedals. The front and rear wheels were both made of iron, with the front wheel larger and the rear wheel smaller. When the cyclist steps on the pedals, the bike will start on its own and run forward. In this way, the cyclist's feet really leave the ground, and the alternate stepping of the feet becomes the rolling of the wheels, which greatly increases the driving speed. In 1842, Macmillan rode this kind of bicycle and ran 20 kilometers a day. Due to his carelessness, he pedaled too fast and knocked down a little girl on the road. He was caught by the police and fined. The crime was rough riding.
In 1861, French Michaud and his son, who were originally carriage repairmen, installed a rotatable pedal board on the front wheel; the saddle of the car was placed on the front wheel, so that unless riding The skills of the car must be very high, otherwise you will not be able to hold the handlebars firmly and you will fall off the car. They gave this two-wheeled vehicle the elegant name "Bicycle" and exhibited it at the Paris Exposition in 1867, which opened the eyes of the audience.
In 1869, after seeing the French bicycles, the British Renault felt that the bicycles were too bulky and began to think about how to make the bicycles lighter. He used steel wire spokes to tighten the rims as wheels; at the same time, he used thin steel rods to make the frame. The front wheels of the car were larger and the rear wheels were smaller. This reduces the weight of the bicycle itself. Starting from Sifulak and continuing to Renault, the five types of bicycles they produced are all quite different from modern bicycles.
The bicycle in its true modern form was born in 1874. During this year, the British man Rossone ingeniously installed a chain and sprocket on the bicycle, using the rotation of the rear wheel to push the bicycle forward. But the front wheel is still large and the rear wheel is small, which looks uncoordinated and unstable.
In 1886, Staley in England was a mechanical engineer. He designed a new bicycle style from the perspective of mechanics and kinematics, and installed front forks and brakes on the bicycle. The wheels were all the same size to maintain balance, and the diamond-shaped frame was made of steel tubes. Rubber wheels were also used for the first time. Staley not only improved the structure of bicycles, but also modified many machine tools used to produce bicycle parts, opening up broad prospects for the mass production and popularization of bicycles. Therefore, he is called the "Father of Bicycles" by future generations. The bicycles that Staley designed are basically the same as today's bicycles.
In 1888, Dunlop, an Irish veterinarian, was inspired by treating gastric bloating in cattle. He glued the rubber tube used for watering in his garden into a round shape, inflated it enough, and mounted it on his bicycle. On wheels, he went to participate in a cycling competition and came out on top, arousing great interest. Pneumatic tires are an epoch-making innovation in the history of bicycle development. They increase the elasticity of the bicycle and prevent it from vibrating due to uneven road surfaces; at the same time, it greatly increases the driving speed and reduces the friction between the wheels and the road surface. In this way, the riding performance of the bicycle is fundamentally changed and the use function of the bicycle is improved. It can be seen from this that from the late 18th century to the early 20th century, the invention and improvement of bicycles took about 200 years, and many people worked hard for it, before it evolved into the current style of riding freely.
The invention of the bicycle
There are many theories about the invention of the bicycle.
① my country is the first country in the world to invent bicycles. The ancestor of the bicycle is the unicycle in my country more than 500 BC. During the Kangxi period of the Qing Dynasty (1662-1722), Huangluzhuang invented the bicycle. Volume 11 of "Unofficial History of the Qing Dynasty" contains: "A two-wheeled cart made by Huangluzhuang is more than three feet long and can seat one person. It does not need to be pushed or pulled, and can move on its own. When traveling, use the hand to turn the axis and turn it around. The journey continues as before, and the journey continues for eighty miles. This is the earliest bicycle in the world.
②The bicycle was invented by Western Europeans. In 1790 AD, the Frenchman Sifulak developed a wooden bicycle without handlebars, pedals, or chains. The car looks like a wooden horse with two wheels nailed to its feet, and the two wheels are fixed in a line. Since the bicycle had no driving device or steering device and the seat was low, Sifulak rode on the bicycle by himself, put his feet on the ground, and pushed backwards hard to make the bicycle move forward in a straight line. In 1817, Baron von Drais of Germany invented a handlebar that could move freely, making it easier to change his bicycle. In 1818, Delais applied for a patent in England. In 1839, K. Macmillan, a British worker, pioneered a pedal bicycle that used a crankshaft mechanism to drive the rear wheel, allowing people to lift their feet off the ground while riding a bicycle. One day in 1861, Parisian carriage and stroller manufacturers Michaud and his sons were repairing a Delais-style bicycle. After repairing it, when they tried it on a ramp, they found that it was difficult to put their feet on the bicycle, so they improved it. A pedal crankshaft was installed on the front wheel, thus creating the Michaud bicycle, which soon began to be mass-produced. Around 1870, France's Ma Zhi made another bicycle with a large driving wheel at the front and a small driven wheel at the back. This kind of bicycle had better operating results. After 1890, the British Humber Company produced a chain-driven, diamond-shaped bicycle. This form of bicycle is still in use today.
③The bicycle was invented by the Russians. One day in September 1801, the Russian serf Artamonov rode a wooden bicycle he made and traveled 2,500 kilometers to Moscow to present a gift to Tsar Alexander I. The bicycles made by Artamonov were relatively similar to those made by the Frenchman Sifulak. When Alexander I saw the bicycle made by Artamonov, he immediately ordered that his slave status be cancelled.
Europeans’ early bizarre design methods
The world’s first truly practical bicycles appeared in the early 19th century. In 1817, the German Derais invented a wooden two-wheeled bicycle with handlebars in Paris, France. After the advent of the bicycle, it quickly became the favored means of transportation for Europeans at that time. Some Europeans in the 19th century also conceived some ideal bicycle pictures.
In the early days of the invention of the bicycle, it was believed that larger wheels allowed faster travel, and two men rode a bicycle with wheels almost as tall as a person.
In the invention stage of the bicycle, some people did not design the two wheels of the bicycle to be placed front and back, but placed the two wheels left and right. The shape of this kind of bicycle is somewhat similar to a wheelchair.
This is an early three-wheeled bicycle designed by Europeans. The balance ability of a three-wheeled bicycle is better, and it is easier for people to learn to ride a three-wheeled bicycle. With the improvement of bicycle technology in the future, three-wheeled bicycles gradually developed into a means of transporting goods.
This is also a three-wheeled bicycle, but the designer placed two power wheels on the front of the vehicle and one auxiliary wheel on the rear. People can also have a passenger in front of them when riding this kind of bicycle. This kind of bicycle is exactly the opposite of the modern concept of bicycles that can carry people on the back.
Composition
①Body part: including the frame, front fork, handlebar, saddle and front fork assembly, etc., which is the main body of the bicycle.
② Transmission part: including pedals, cranks, sprockets, chains, central shafts and flywheels, etc. The pedals are stepped on by humans, and the wheels are driven to rotate through the above transmission parts to drive the vehicle forward.
③Moving parts: front and rear wheels, including front and rear axle components, spokes, rims (rims), tires, etc.
④Safety devices: including brakes (brakes), lights, bells, reflective devices, etc.
According to needs, some accessories can be added, such as brackets, hangers, safety forks, fenders, air pumps, etc. In addition, sports bikes, racing bikes, mountain bikes, etc. equipped with a speed change mechanism are also equipped with speed change controllers and front and rear derailleurs.
Classification
According to the purpose, it can be divided into heavy-duty vehicles, ordinary vehicles, light vehicles, sports vehicles, competition vehicles, mountain bikes, special vehicles (such as exercise vehicles, acrobatic vehicles), etc.
According to the objects of use, it can be divided into men's cars, women's cars and children's cars.
According to the wheel diameter, it can be divided into 71 cm wheels, 66 cm wheels, 61 cm wheels, etc.
According to the materials used for the main components such as the frame, it can be divided into carbon steel cars, alloy steel cars, aluminum alloy cars, etc.
According to the structure of the frame, it can be divided into pole-stacked bicycles, detachable bicycles and integral bicycles.
Principle
Among the 25 components of a bicycle, including the frame, tires, pedals, brakes, and chains, the basic components are indispensable. Among them, the frame is the skeleton of the bicycle, which bears the largest weight of people and cargo. According to the working characteristics of each component, it can be roughly divided into guiding system, driving system and braking system:
1. Guiding system: composed of handlebars, front forks, front axles, front wheels and other components . The rider can change the direction of travel and maintain balance by manipulating the handlebars.
2. Drive (transmission or walking) system: composed of pedals, central shaft, sprocket, crank, chain, flywheel, rear axle, rear wheel and other components. The pedaling force of human feet is transmitted by the pedals through cranks, sprockets, chains, flywheels, rear axles and other components, thereby making the bicycle continue to move forward.
3. Braking system: It consists of brake components. The rider can control the brake at any time to slow down and stop the moving bicycle and ensure driving safety.
In addition, for safety, aesthetics, and practicality, lights, brackets and other components are also assembled.
Components
1. The frame component is the basic structure of the bicycle, and it is also the skeleton and main body of the bicycle. Other components are also directly or indirectly installed on the frame.
There are many structural forms of frame components, but they can generally be divided into two categories: men's frames and women's frames.
The frame is generally made of ordinary carbon copper tubes that are welded and assembled. In order to reduce the weight of the tube and improve its strength, higher-end bicycles are made of low-alloy steel tubes. In order to reduce the resistance of fast driving, some bicycles also use streamlined steel pipes.
Since bicycles rely on the human body’s own driving force and riding skills to travel, the frame becomes an important structure that can withstand the impact load generated by the bicycle while it is driving and can carry the human body comfortably and safely. The manufacturing accuracy of the body and frame components will directly affect the safety, stability, and briskness of the ride. Generally speaking, the spokes are of equal diameter. In order to reduce gravity, there are also spokes with large diameters at both ends and small diameters in the middle. In order to reduce air resistance, the spokes are made into flat streamlines
2. Tires: divided into soft and soft. There are two types of side tires and hard side tires. The soft-sided tire has a wider cross-section, can completely wrap the inner tube, has a relatively large landing area, and can be suitable for driving on a variety of roads. Hard-sided tires are light in weight and have a small landing area, making them suitable for driving on flat roads. They have the advantages of low resistance and brisk driving.
The pattern on the tire is to increase friction with the ground. The tire width of mountain bikes is particularly wide and the tread pattern is deep, which is also suitable for off-road mountain use.
3. Pedal component: The pedal component is assembled on the left and right cranks of the central axis component. It is a device that converts translational force into rotational force. When riding a bicycle, the pedal force is first transmitted to the feet. The pedal shaft rotates the crank, bottom bracket, and chain flywheel to rotate the rear wheel, thereby moving the bicycle forward. Therefore, whether the structure and specifications of the pedal components are appropriate will directly affect whether the rider's foot position is appropriate and whether the bicycle can be driven smoothly.
Pedal: can be divided into integral pedal and combined pedal. No matter what style of pedal, it must have a tread, which must be safe and reliable, have certain anti-slip properties, and can be made of rubber, plastic or metal materials. The pedals must turn freely.
4. Front fork component: The front fork component is located in the front part of the bicycle structure. Its upper end is connected to the handlebar component, the frame component cooperates with the front tube, and the lower end cooperates with the front axle component to form a bicycle. guidance system.
Rotating the handlebars and front forks can change the direction of the front wheel, which plays a guiding role in the bicycle. In addition, it can also play a role in controlling the driving of the bicycle.
The force on the front fork component is of the nature of a cantilever beam, so the front fork component must have sufficient strength and other properties.
5. Chain: The chain is also called the chain and roller chain, and is installed on the connecting wheel and flywheel. Its function is to transmit the pedal force from the crank and sprocket to the flywheel and rear wheel to drive the bicycle forward.
Sprocket: Made of high-strength steel to ensure it reaches the required pulling force.
6. Flywheel: The flywheel is screwed and fixed on the right end of the rear axle with an internal thread, keeping the same plane as the sprocket, and is connected to the sprocket through a chain, forming the bicycle's drive system. Structurally, it can be divided into two categories: single-stage flywheel and multi-stage flywheel.
The single-stage flywheel is also called a single-sprocket flywheel. It is mainly composed of a jacket, a flat gear and a core, a jack, a jack spring, a washer, a wire block, a few steel balls and other parts.
The working principle of the single-stage flywheel: when the pedal is stepped forward, the chain drives the flywheel to rotate forward. At this time, the internal teeth of the flywheel are included with the jack, and the rotational force of the flywheel is transmitted to the core through the jack. , the core drives the rear axle and rear wheel to rotate, and the bicycle moves forward.
When the pedal is stopped, the chain and the jacket do not rotate, but the rear wheel still drives the core and the jack to rotate forward under the action of inertia. At this time, the internal teeth of the flywheel slide relative to each other. This compresses the core into the slot of the core, and the jack compresses the jack spring. When the tip of the jack tooth slides to the top of the inner tooth of the flywheel, the jack spring is compressed the most. If it slides forward a little, the jack is bounced by the jack spring onto the tooth root, making a "click" sound. The core rotates faster, and the weight quickly slides on the internal teeth of each flywheel, making a "click-click" sound. When the pedal is stepped on in the opposite direction, the coat will rotate in the opposite direction, which will accelerate the sliding of the jack and make the "click-click" sound more rapid. Multi-stage flywheel is an important component in bicycle transmission.
The multi-stage flywheel is based on the single-stage flywheel, adding several flywheel pieces, combined with the sprocket on the central axis, to form various transmission ratios, thus changing the speed of the bicycle.
① Impact strength of frame and front fork assembly: There are two measurement methods. The first is the drop weight impact test. The assembly is erected vertically, and a 22.5kg weight is placed 180mm above the front fork. Under one impact of the weight, the permanent deformation of the assembly cannot exceed 40mm, and there is no visible deformation to the naked eye. Cracks; the second is the drop impact test. Place a 70kg weight on the saddle of the component, move its center of gravity to the vertical position of the rear axle, and drop forward freely. After two repeated tests, no cracks should be visible to the naked eye. In addition, the frame and front fork also need to undergo a lateral load strength test, and the load weight varies depending on the model.
② The assembly firmness of the handlebar and the front fork: The measurement method is to apply a torque of 25N·m on the handlebar cross tube (usually replaced by a test rod) after the handlebar is installed into the front fork. The handle cannot be turned.
③Strength of front and rear wheels: The measurement method is to clamp the wheel with spokes and corrected flat and apply a force of 178N on its side. After 1 minute, the permanent deformation shall not be greater than 1.5 mm.
④Brake braking performance: The test method is divided into two types according to the transmission speed ratio of the vehicle. One is for bicycles with a stroke of 5m or more, the test speed is 24km/h; the other is for bicycles with a stroke of less than 5m, the test speed is 16km/h. There are two types of braking performance: dry state and wet state that simulates rainy days. At the specified test speed, when the front and rear brakes are used at the same time, the braking distance in the dry state shall not be greater than 5.5m, and the braking distance in the wet state shall not be greater than 15m.
⑤Safety device: The bicycle must be equipped with a bell or light, as well as a reflector (commonly known as a return light). The reflector is illuminated by motor vehicle headlights or other external light sources to reflect light of sufficient intensity to alert the other party to pay attention and thereby protect oneself. There are three types of reflectors: front, side and rear reflectors. The front ones are white, the rear ones are red, the front wheel side wheels are white or amber, the rear wheel side wheels are white or red, and the pedals are white or amber.
Durability can be divided into two aspects: internal and external. The inherent durability performance requires ensuring a certain structural strength, requiring heat treatment, carburizing and quenching of some parts that are prone to wear, such as the baffle bowls of the front, middle and rear axles, flywheel gears, chain cores and rollers, and foot brake parts. , to improve surface hardness. The durable performance of the appearance is achieved by electroplating and coating (paint) to prevent corrosion and increase the beauty of the appearance. Electroplating is to coat the original metal surfaces such as handlebars and rims with copper, nickel, chromium or three metal coatings of nickel, nickel and chromium. Other coatings can also be selected depending on resource conditions and anti-rust performance requirements. For some minor small parts, bright galvanizing process is used. Coating uses high-voltage electrostatic method to spray the surface of the frame and front fork. The paint surface should be plump, gorgeous, and have certain anti-rust properties and paint film adhesion.
Development Trends Due to differences in living standards across countries, the purposes of using bicycles vary. In some countries, cyclists use tourism, exercise, and children's sports as their main purposes. They generally use multi-speed bicycles, off-road bicycles, etc. bicycles and mountain bikes; in some countries, bicycles are mainly used as means of transportation, and light vehicles and multi-speed bicycles are mostly used. In general, bicycles are developing in the direction of being beautiful, light, durable, new, and cheap. Beauty means beautiful appearance, bright colors, gorgeous and not vulgar; light means light weight and light riding; strong means high strength; new means new styles and many varieties; cheap means low cost and strong competitiveness.
Maintenance
Bicycle lubrication
Bicycles are large-scale human-powered machines. The lubrication structure types include sliding friction and rolling friction, point friction and linear friction. , there are fluid lubrication and boundary lubrication, oil lubrication and grease lubrication.
The key moving friction parts of the bicycle are the center shaft and the front and rear axles, which all use ball bearings and are lubricated with No. 2 calcium-based grease. During each maintenance, the balls, ball grooves and covers must be cleaned, and No. 2 calcium-based grease should be evenly applied into the ball grooves. Special balls (beads) with smooth and complete surfaces, uniform particles, and uniform sizes should be placed around the shaft. ), and then close the cover to prevent dust and impurities from getting mixed in. Then every quarter or six months, drop 2-5 drops of bicycle lubricating oil, or low-viscosity lubricating oil at 40°C and viscosity 7-15mm2/s, into the oil hole (with an oil hole) or the end of the shaft. But before refueling, be sure to remove dust and dirt near the refueling hole or shaft end to avoid wear. Generally, lubricating oil cannot be mixed when lubricating with grease. Oil and grease cannot be mixed under normal circumstances. But it is a special case on bicycles. In order to simplify the equipment, there is no grease mouth, and only lubricating oil can be added to improve lubrication.
Secondly, the lubrication of the chain and the gear plate is a mixed friction of sliding friction and rolling friction, and most of them are in a boundary lubrication state. Therefore, the friction conditions are harsh, so it is necessary to use friction materials with higher adhesion and lubricity. Good lubricating oil, especially most of them are open type and work in dusty conditions, causing serious wear and tear on the chain and gear plate. Therefore, they should be cleaned at any time (quarterly or half a year) and replaced with new oil according to the situation (quarterly or half a year). , it is most suitable to use lubricating oil with a relatively high viscosity (viscosity 10-20mm2/s at 40°C), but generally the same lubricating oil added to the three-axis is used, which is more convenient.
Normal riding use
Clean the car: In addition to keeping your car as dazzling as when it was new, cleaning the car will also avoid rust on the frame. If you ride in a heavy rain When riding a car in medium or muddy conditions, you should clean it as soon as possible after riding. Pay attention to the following points when washing your car: If there is not much mud on the car body, or it is mostly dust, you can use a rag to wipe it clean, or use Brush clean with a large bristle brush. Do not use high-pressure water jets to remove sludge from the car body. Although this method is very efficient, it may force sewage into the bearings, which may cause damage to the bearings. If there is a lot of sludge on the car body, you should use a brush and soapy water to wash away the sludge, rinse it with clean water, and then wipe it dry with a cloth. After the car is clean, remember to check whether the paint is peeling off. The steel frame will start to rust after the paint peels off, while the aluminum alloy or carbon fiber and titanium alloy frames will not rust and will only affect the appearance. After washing the car with water, remember to dry the chain and re-oil it.
Check the brake pads: Remove debris from the brake pads to ensure their braking power. If they are severely worn, they must be replaced.
Re-oil the cable tube: If the brakes or gearshifts do not work properly, the friction between the inner and outer cables may be too great. Remove the outer cable from the tube stop, apply butter to the inner cable, and then reinstall it. If the operation is still not smooth after this, consider replacing the inner and outer cable tubes.
Chain oiling: After dripping lubricating oil on the chain, wipe off the oil on the outside of the chain after about ten minutes. As long as there is oil on the internal moving parts of the chain, there is no excess on the outside. Lubricating oil will stick to dust and make cleaning more troublesome, so it's best to wipe it clean. In addition, if you use spray can lubricant, remember to wipe off the oil that drips on other parts after applying the oil.
Interim periodic maintenance
Check the chain: the chain will stretch after long-term use. The pitch of the chain is 0.5 inches. When measuring 24 links of the chain, the length should be 12 inches. , if its length has exceeded the normal length by 1/8 inch, the chain should be replaced.
Clean the chain: If there is a lot of sludge inside your chain, it may be time to clean it. To clean the chain, you can use a chain washer, or remove the chain, find a container, fill it with solvent oil, and place it. After inserting the chain, shake it to wash it, and finally take it out to dry and oil it.
Check the flywheel and large chainring: If the flywheel has skipped teeth after updating the chain, replace the flywheel. If the teeth of the large chainring are greatly worn and the chain is stuck, they should also be replaced. , check the fixing screws of the large chainring. If they are loose, they must be re-tightened.
Check the rim: Check whether there are subtle cracks near the valve hole and the steel wire hole. If there are cracks, replace the rim as soon as possible, lift the wheel, rotate the wheel, and observe whether the rim will If the brake pads are rubbed, the rim must be readjusted.
Check the steel wire: Check whether the steel wire of the front and rear wheels is broken. If so, replace it. After replacing the steel wire, you must readjust the rim. When adjusting the rim, observe the direction of the rim deflection, such as If it deviates to the right, loosen the right steel wire near that part of the rim and lock it on the left. If it deviates to the left, vice versa. The left and right deflection of the rim should be less than 2mm.
Check the driver: Check whether the driver was deformed in the accident and whether there are cracks in the seat tube locking part. If so, update the driver.
Check the seat cushion and seat cushion rod: Remove the seat cushion rod and check whether there is deformation or cracks. If not, put a thin layer of butter on it and put it back. Check whether the seat cushion is damaged and whether the bracket below is damaged. In good condition, if there is a problem, replace it.
Long-term regular maintenance
Check the hub: Remove the front and rear wheels, check whether there are cracks near the wire holes, and replace them immediately if there are any. Turn the hub shaft by hand to see, and then add up and down Shake. If you feel any gap or extremely loose, disassemble the hub shaft, clean the oil inside, reinstall new butter, and reassemble the hub shaft. Remember to adjust the bearing so that the shaft can rotate smoothly. , but there will be no up and down swing gap.
Check the Tianxin: Remove the chain, hold the crank and shake it left and right. If there is shaking, tighten the fixing screw. If it still shakes, the Tianxin bearing must be adjusted; put your ear against the seat cushion and rotate the crank , the sound you hear should be a smooth "hoo-hoo" sound. If you hear rattling or other strange sounds, it means that the bearing is damaged and the Zhongtian core should be replaced.
Check the pedals: Remove the pedals and use a 15mm open-end wrench. Note that the pedal on the left has left teeth. Do not remove it incorrectly when disassembling. The pedal bearings do not need to be adjusted, but they still need to be checked. If used If it is a cassette pedal, check whether its mechanism operates normally and lubricate it. Check the transmission: Check whether the various action parts of the transmission are shaking. If so, it means that the transmission is severely worn and should be replaced. If not, lubricate the action parts with oil.
Shock absorber maintenance: The front wrist of the hydraulic shock absorber should be disassembled and replaced with new shock absorber oil. If it is in the form of Polyurethane, check whether the Polyurethane has cracks or deformation. If so, If necessary, please contact the original purchaser for shock absorber repairs.
Check the frame: Check all the paint. If there is corrosion to the frame, the frame must be replaced. If the frame is deformed due to impact, it should also be replaced.
Update all internal and external cable conduits: All cable conduits have become worn over time and are therefore recommended to be replaced to maintain their performance.
Outdoor emergency repair
When riding in the wild, the car breaks down and you have to walk home, which is really disappointing. Therefore, in order to avoid this situation, Always remember to bring tools with you when you go out riding. Don’t think that accidents won’t happen. It’s always good to be prepared.
The following introduces common fault conditions and repair methods in the wild:
Tire blowout: This is a common thing. When a tire blowout occurs, remove the wheel, use the tire removal lever to remove the tire, and remove it. Inner tubes, if you carry a spare tire, just install the spare tire. If you don't have a spare tire, you need to repair the tire. When repairing the tire, first find the hole, and use sandpaper or rough tools to slightly grind the area around the hole. , apply tire repair glue, wait until it is almost semi-dry, put the tire repair patch on it, press it firmly, then inflate it to check whether there is still air leakage, and finally put back the inner and outer tire and inflate it enough.
How to choose a bicycle
The main things to choose a bicycle are firstly whether it is a good frame, secondly whether it is composed of good parts, and thirdly whether the assembly technology is good. Only when these three factors are combined scientifically can it be considered a good bicycle.
1. Frame:
1. What is the frame?
The bicycle frame is equivalent to the human skeleton. With the bicycle frame, various bicycle parts can be installed. The frame is composed of iron, aluminum alloy and other materials, and the angle formed by the length of the tube affects the characteristics of the overall bicycle. For example, a bicycle that rides well in a straight line, a bicycle that turns easily, a bicycle that rides comfortably, etc. Many of the factors that determine these factors come from the frame.
2. What makes a good bicycle frame?
Lightness, strength, and good elasticity are one of the goals pursued by the frame. In order to achieve this goal, it also depends on the craftsmanship of each frame manufacturer. For example, whether the designed frame is designed according to the strength and characteristics of the material, and whether the welding process is mature. These directly affect the appearance, strength and elasticity of the frame. The more important thing is to spray paint. A good frame should be sprayed evenly and with 3-4 layers of paint. Don't underestimate the spray paint. Good spray paint can make the bicycle easy to maintain and less likely to rust. If a frame that does not meet the above requirements is used to install a bicycle, it is possible to produce a bicycle that cannot ride in a straight line or is difficult to turn, or a bicycle that retreats quickly.
3. What materials is the frame made of?
The most common ones are iron frames, but iron frames are also divided into chromium-molybdenum steel, high-strength steel, ordinary steel, etc. The frame can be made by adding other components to the iron. For example, thinner pipes make the overall frame lighter. Recently, without reducing strength, frames using materials other than iron have appeared, such as aluminum alloy materials. In bicycle racing, there are frames using titanium carbon fiber materials.