1, navigation system
It consists of handlebar, front fork, front axle and front wheel. The rider can change the driving direction and keep his body balanced by manipulating the handlebar.
2. Drive (transmission or walking) system
It is composed of pedal, central shaft, sprocket, crank, chain, flywheel, rear axle, rear wheel and other parts. The pedaling force of people's feet is driven by pedals through crank, sprocket, chain, flywheel, rear axle and other parts, thus making the bicycle move forward continuously.
3. Brake system
It is composed of brake components, and the rider can control the brake at any time to slow down and stop the running bicycle and ensure the driving safety. In addition, for safety and beauty, as well as from a practical point of view, it is also equipped with lights, brackets and other components.
Specific material
1, framework
Frame assembly is the basic structure of bicycle, and it is also the skeleton and main body of bicycle. Other components are also directly or indirectly mounted on the frame. There are many structural forms of frame parts, but they can be roughly divided into two categories: men's frames and women's frames.
The frame is generally composed of ordinary carbon and copper pipes welded together. In order to reduce the weight of steel pipes and improve the strength, low alloy steel pipes are used in high-grade bicycles. In order to reduce the resistance of fast driving, some bicycles also use streamlined steel pipes.
2. Outer tire
There are two kinds of soft side tires and hard side tires. The cross section of the soft sidewall tire is wide, which can completely wrap the inner tube, and the landing area is relatively large, so it is suitable for driving on various roads. Hard-edged tires have the advantages of light weight, small landing area, small resistance and light driving.
3. Pedal parts
The pedal assembly is assembled on the left and right cranks of the middle axle assembly, which is a device that converts horizontal force into rotational force. When riding a bicycle, the pedal force is first transmitted to the pedal assembly, and then the pedal shaft drives the crank, the middle shaft and the chain flywheel to rotate, so that the rear wheel rotates, thus making the bicycle move forward.
4. Front fork parts
The front fork assembly is located in the front part of the bicycle structure, and its upper end is connected with the handlebar assembly, the frame assembly is matched with the front tube, and its lower end is matched with the front axle assembly to form the guiding system of the bicycle.
Turning the handlebar and the front fork can change the direction of the front wheel and play a guiding role in the bicycle. In addition, it can also play a role in controlling the operation of bicycles. The front fork is a cantilever beam, so the front fork must have sufficient strength and other properties.
5. Chain
Chain, also known as cart chain and roller chain, is installed on the connecting wheel and flywheel. Its function is to transfer pedal force from crank and sprocket to flywheel and rear wheel to drive the bicycle forward. The sprocket is made of high strength steel to ensure the required tension.
6. Flywheel
The flywheel is fixed at the right end of the rear axle through internal thread, keeps the same plane with the sprocket, and is connected with the sprocket through a chain to form the driving system of the bicycle. Structurally, it can be divided into two categories: single-stage flywheel and multi-stage flywheel. Single-stage flywheel, also known as single sprocket flywheel, is mainly composed of jacket, flat block and core, jack, jack spring, washer, steel wire block and several steel balls.