The system structure

　　The bicycle frame, tire, pedal, brake, chain and other 25 components, its basic components are indispensable. The frame is the skeleton of the bicycle, and it bears the most weight. According to the working characteristics of each part, it can be divided into a guide system, a driving system and a braking system.

　　1. Guidance system: it is composed of handlebar, front fork, front axle, front wheel and other parts. The rider can change the direction of the car by manipulating the handlebars and maintain the balance.

　　2. Drive (transmission or walking) system: it consists of pedal, middle shaft, tooth disk, crank, chain, flywheel, rear axle, rear wheel and other parts. The pedal force of the human foot is driven by the pedal through the crank, the chain wheel, the chain, the flywheel, the rear axle and so on, so that the bicycle keeps moving forward.

　　3. Braking system: it is composed of brake parts, and the rider can control the brake at any time, so that the driving bicycle can slow down and stop, so as to ensure the safety of driving.

　　In addition, for safety and aesthetics, as well as from practical, also equipped with headlights, supports, bell and other parts.

　　composition

　　1. Body parts: including.

　　Bicycle frame, front fork, handlebar, saddle and front fork, etc., are bicycles.

　　The main body. The driving part consists of pedal, crank, chain wheel, chain, shaft and flywheel, etc., which is driven by the manual pedal and driven by the driving wheel.

　　2. Operation part: the front and rear wheels, including the front and rear axle parts, spokes, rims (car rings), tires, etc.

　　3. Safety device: including brake (brake), headlight, bell, reflector, etc.

　　According to the need, can also add some accessories, such as bracket, coat hanger, insurance fork, fender, gas cylinder and so on. In addition, sports cars, racing cars and mountain bikes equipped with variable speed mechanism are equipped with variable speed controller and front and back chain conveyor.

　　4, hands and feet of hybrid bicycle: on the traditional bicycle frame added a metal box, box contains all kinds of transmission parts, through the force of interaction, so as to realize the hybrid spender and simple push carts to action, so as to realize the car can let the car forward, not only energy, but also fitness.

　　parts

　　1. The frame part is the basic structure of the bicycle, which is also the skeleton and main body of the bicycle, and other parts are installed directly or indirectly on the frame.

　　There are many structural forms of frame parts, but they can be divided into two categories: men's frame and female frame.

　　Because the bike is a driving force on the body's own and cycling skills while driving, the frame became the bicycle on the road under impact load produced by and comfortable and safely carry important structure of the body, frame components manufacturing, precision will directly affect the safety of riding, smooth, and fast. In order to reduce the gravity, the spokes are also made into large and small diameter spokes, and to reduce the air resistance, the spokes are made into flat streamlines.

　　2. Outer tube: two types: soft edge and hard edge. Soft side tire section is wider, can cover the inner tube completely, the land area is larger, can be suitable for a variety of roads. The hard edge is light, and the landing area is small and suitable for running on the smooth road. It has the advantages of small resistance and light driving.

　　The pattern on the outside is to increase friction with the ground. Mountain bikes are especially wide in width and have deep patterns.

　　3. Pedal parts: pedal parts assembly on the axial component of the crank is a flat power turn into power device, bike riding, pedal force to pedal parts first, and then by the pedal crank shaft, tooth plate, axis, chain wheel, rear wheel rotation, so that the bike forward. Therefore, the structure and specifications of the pedal components are appropriate, which will directly affect whether the position of the rider is suitable, and whether the driver of the bicycle can be carried out smoothly.

　　Foot: can be divided into integral foot and combination foot. No matter what style of foot must have foot surface, must be safe and reliable, have certain anti-slip performance, can choose rubber, plastic or metal material to make. The foot must turn flexibly.

　　4. The front fork parts: front fork parts in the front part in the bicycle structure, its top and handlebar components are linked together, frame assembly with the former, together with the bottom and front axle parts, bicycle guiding system.

　　Turning the handlebars and the front fork can change the direction of the front wheel and play the guiding role of the bicycle. In addition, can play the role that controls bicycle to drive.

　　The force of the forked part is of the cantilever type, so the front fork must have sufficient strength and so on.

　　5. Chain: chain is also known as chain and roller chain, which is installed on the connecting wheel and flywheel. The effect is to transfer the pedal force from the crank, the sprocket to the flywheel and the rear wheel to drive the bike forward. Sprocket: made of high strength steel to ensure that it meets the required pull.

　　6. Flywheel: the screw thread inside the flywheel is fixed on the right end of the rear axle, keeping the same plane with the sprocket, and connecting the chain with the sprocket to form the driving system of the bicycle. The structure can be divided into two categories: single-stage flywheel and multi-stage flywheel.

　　The single-stage flywheel is also known as single chain wheel, which is mainly composed of coat, flat and core, jack, jack, washer and wire. The working principle of the single stage flywheel: when stepping forward move pedal, chain drive the flywheel rotation forward, while the flywheel gear and contains one thousand jins, flywheel rotating force to the core by one thousand jin, core drives the rear axle and rear wheel rotation, bicycle went forward.

　　When to stop when the foot pedal, chain and coat are not rotating, but the rear wheels under the effect of inertia still drive the core and one thousand jins forward rotation, when reverse step move pedal, coat reverse rotation, will speed up one thousand jins of sliding, the "clicking" sound more urgent. The multi - stage flywheel is an important part in the bicycle transmission gear.

　　The multi-stage flywheel is based on the single-stage flywheel, adding several flywheels, which are combined with the sprocket on the central axis to form various transmission ratios, thus changing the speed of the bicycle.