A bicycle (aka a bike) is very practical andIt is a convenient vehicle that has become densely integrated into the life of modern man. Every year the number of cyclists on the city streets is growing, which can not but rejoice. In addition, there are people for whom the bicycle is not just a vehicle, but the meaning of life and the main way to earn money. The number of professional sports using a bicycle today is also quite large.
Whatever the bicycle (and he has enoughmany kinds), its basic design remains unchanged. Despite the fact that it is quite simple, as in any other technique, there are a number of nuances. Today we will discuss in detail the structure of the bicycle and the elements of its construction.
Like a car, the bike has a carrierThe construction on which all other elements are attached. This structure is called a frame. It is the type of frame that determines the purpose of the bicycle, and its quality influences the life of the bicycle.
The frame is a rhomboid frame, welded from such elements:
- Front pipes (upper, lower).
- Seat tube.
- Top feathers.
- Lower feathers.
How they connect, you can see in the illustration below.
In the modern bicycle market, you can find a huge number of options for frames. They are divided into the following classes:
- The tricky ones.
The difference between the types of bicycle frame can be expressed not only in its appearance, but also in materials of manufacture, strength characteristics, as well as weight.
Full-size and folding
Bicycles can be full-sized and foldable.The difference of the latter is expressed by the presence of at least one joint on which the frame can be folded. Consequently, they are easier to transport in public or personal transport. To put a normal bicycle, for example, in the luggage compartment of a car, it will have to be dismantled. Folding bicycles are good in terms of transportation, but they are inferior to full-size models in driving performance and reliability. As a rule, these are amateur urban bicycles, which are not subject to high demands on speed and strength. Especially popular among bicycle lovers is the folding bike "Stealth". For the sake of justice it is worth noting that you can disassemble a modern bicycle for transportation in a car in a few minutes. The collection will take a couple of minutes more. Therefore folding bicycles are bought much less often.
The material from which the frame is made is the most important indicator of a bicycle and determines its cost. For modern bicycles use steel, aluminum and carbon frames.
Steel most often used for urban bikes.The material is characterized by high strength and resistance to mechanical influences. The drawback of the steel frame is its weight and weak flexibility. All this is bad for the dynamics of the bicycle.
Aluminum - Durable, lightweight and flexible material. Aluminum frames, in comparison with steel analogs, have better dynamism and depreciation. The price is also higher.
Carbon - Carbon fiber, which is used forthe manufacture of expensive bicycle frames. In comparison with metal analogues, carbon frames are particularly strong, durable, shock-resistant, light and manoeuvrable.
An important part of the bicycle are the wheels.They hold the frame in an upright position and rotate the bicycle into motion. The wheel is arranged quite simply. It consists of a bushing, rim, chamber and tire.
Sleeve - the central part of the wheel, consisting of an axis,bearings and washers. The main task of the bushing is to set and maintain the torque. At the rear bushing, the internal device is more complicated than the front one, since it participates in the unwinding of the wheel. On road models of simple design, in the rear hub the brake mechanism is additionally built in. The structure of the rear wheel of a high-speed bike differs in that the gearbox is attached to the bushing. In the planetary bushings, a hidden mechanism for shifting gears is also placed.
Rim - a ring that is attached to the sleeve through the spokes.The geometry of the rim and the level of the tension of the spokes determine the stability of the wheel to dynamic loads and damages. The rims for the bicycle wheel are made of aluminum, and the spokes are made of light alloys. The head for adjusting the tension of the spokes is located on the rim side.
The camera (bus) - a rubber hollow article that falls onrim and pumped with air. A tire is placed on top of the camera. Thus, the only element of the camera that contacts the "outside world" is the nipple, through which the chamber is pumped with air. To prevent damage to the tire from the head of the spokes, a rubber flipper is placed on the inside of the rim.
Tire - sheath protecting the tire from mechanicalImpacts and creates a grip of the wheel with the road. The tire consists of sides, sidewalls and tread. Depending on the purpose of the bicycle, it is equipped with one of four types of tires:
- Cracks and half-spices. Used for highway bicycles, for flat roads.
- Road. Has an average tread pattern. Suitable for both highway and dirt roads.
- Aggressive. They have a pronounced tread pattern and are intended for mountain roads.
- Hybrid. A bit more aggressive than road tires, but not so passable as the mountain.
For visibility of the bicycle in the dark, put on the spokes reflective elements - orange or red catapults.
The bicycle is controlled via the steering knot. It consists of the following elements:
- Steering column.
- Steering wheel.
- Directly steering wheel.
The structure of the fork of the bicycle is not very specialcomplexity. The plug is an intermediate node between the front wheel and the steering wheel. With the help of a rod it is installed in the front glass of the frame. The steering wheel is inserted into the fork, and the wheel is attached to it through the ears of the legs (dropouts). In order for the plug to rotate freely during the turn, a steering column is installed in the glass. It consists of: upper and lower cups, bearings, and also fixing rings. The cups are either pressed in, or screwed onto the internal thread of the glass. The rings are mounted on the rod, which is firmly fixed in the steering column.
The steering wheel consists of two elements: a horizontal pipe and a vertical stem (removal). Depending on the bending of the horizontal pipe, there are such types of bicycle steering:
- Curved down.
- Curved up.
Removal is an intermediate partbetween the horizontal tube of the rudder and the adjustment tube. It determines the distance between the steering wheel and the frame. The longer the take-off, the more horizontal the cyclist will be during the ride. On bicycles of simple design take-out is not put.
Amortization refers to the ability of a bicycle to dampen vibrations and soften impacts. The traditional damping system is located in the front fork. Amortization forks are of several types:
The length of the fork stroke, the speed of rebound and the blockingare regulated by means of special structural elements. Forks that are not equipped with an amortization system are called rigid. They are used for road and road models. In addition to standard depreciation, mountain bikes can be equipped with an additional rear shock absorber, which alleviates the vibrations of the frame when passing bumps.
Transmission refers to the elements without which the bicycle will not go. The structure of this node, in comparison with others, differs in complexity and a large number of mechanisms. The latter include:
- Leading stars.
- Connecting rods.
- Led stars.
- Switches of speeds.
Carriage unit is located in the lower glass of the frame.The structure of the bicycle carriage is simple. It serves as a connecting node between the front stars and the connecting rod pair. Due to the fixed bearings on which the through axle is planted, the carriage ensures stable rotation of the pedals, without turning. Carriages come in two types: cartridge and with open bearings.
Connecting rods They are called to connect the carriage with the pedals.They can be attached to a square or splined mount. The connecting rods come complete with a front sprocket (or asterisks), which is attached to one of them (right).
Pedals - this is the footrest, which through the connecting rods transmit mechanical energy to the carriage. Depending on the application, the pedals are of the following types:
- Classical. They are installed on amateur bicycles. The engagement of shoes is purely due to frictional force.
- Contact. They have special inserts for contact with bicycle shoes.
- Extreme. They have a wide surface and inserts-fixatives.
- With a strap.
- Mini pedals.
Rear stars The transmissions are attached to the rear hub. Several rear stars fall on one front. Stars of small size are responsible for high transmissions, and large ones for low ones.
Chain plays the role of a link between the front(leading) and rear (driven) stars. The structure of a high-speed bike differs in that it has several stars in front and behind. With the help of switches, the chain is transferred from one star to another. Switches are controlled by coins located on the handlebars. Contact between coins and switches takes place through the drive cables. Types of speed switches on the bike are few: coins can be lever and drum. On a bicycle with one gear, there are no switches, and one star is located in front and behind.
Brakes are the most important system, without which it is highly discouraged to operate a bicycle. The structure of the brakes can be different. There are three types of brake bike systems:
- Rim (they are also "W-break" or "mites").
Brake brake - device equipped withpads, which clamp the rim of the wheel, by pressing the lever located on the handlebar. "Ticks" are installed on the place of attachment of the wings (shields protecting the bicyclist from the litter flying from the wheels). Such brakes can be used both independently and in tandem with other types.
The disc brake is more complicated.It consists of a disk (the brake surface fixed on the wheel hub), a caliper and a drive (lever with a cable). The calipers are fastened with brake pads that clamp the disc when the handle on the handlebar is pressed. Disc brakes respond more "responsively" to pressing the lever, as their pads have a smaller stroke. These brakes can be either simple mechanical, or more sophisticated - hydraulic.
Drum-bushing brakes are a relicpast, but still installed on simple road bikes. The drum is located directly in the rear bushing. When the pedals are turned backwards, it releases the pads, which, when in contact with the working surface, stop the wheel.
This is the simplest element, but without it you can notto introduce a bicycle. The structure of the saddle is almost identical for different types of bikes. Differences can be in shape, width, length and softness. On sports bicycles the saddles are narrow, oblong and firm. And for amateur, such as the folding bike "Stealth", for example, they are wide and soft. Some models are additionally spring-loaded from the bottom. The seat is installed on the seat post, which fits into the pipe with the same name and is clamped with a special mechanism. The position of the pin in the pipe determines the height of the landing.
As you can see, the bicycle, whose structurewe today considered in detail, it is not so simple. As described above, all the bikes work. And even the most original designs of bicycle-homemade differ from it only by the presence of additional elements.