Suspension type (fork)
Front fork suspension type (if available, see "Suspension"). All shock absorption systems in bicycles work in two directions: vibration damping (damping) and impact energy absorption (cushioning). Accordingly, they have two main components: a damper and a shock absorber. Depending on the design features of these elements, the following types of depreciation are distinguished:
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Spring-elastomer. In this case, the role of a shock absorber is played by an elastic spring, and the role of a damper is played by a rod made of an elastic, well-compressible material, the so-called elastomer. This type appeared as a development of conventional spring damping systems, it is more durable, but poorly suited for low temperatures — the elasticity of the elastomer in such conditions decreases, which negatively affects the characteristics of the system.
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Spring-oil. Systems using a spring as a shock absorber and an oil cartridge as a damper. This design is somewhat more resistant to low temperatures than spring-elastomer, and in general has quite good characteristics, due to which it is quite widely used in various types of bicycles. The main disadvantage is the higher (on average) cost.
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Air-oil. Combined systems consisting of an air cylinder that acts as a shock absorber and an oil cartridge that acts as a damper. They appeared as a development of “pur
...e” air systems, which had a serious drawback: even with high-quality maintenance, the seals wore out rather quickly, which could disable the shock absorber. Air-oil systems are more durable and easier to maintain, while being quite efficient and weighing little. The latter is especially valuable for cross-country (see "Purpose"), where it is required to combine depreciation with a low weight of the machine.Front rotor
Front rotor.
The front disc brake rotor is a perforated metal plate attached to the wheel hub. The reduction in speed of the bike occurs as a result of the compression of the brake disc by the pads, which are driven by cable tension (in mechanical type systems) or by means of a hydraulic circuit (in hydraulic disc brakes). The diameter of the front rotor can vary from 140mm to 220mm. The higher the number, the more efficient the brake is.
Front hub model
The model of the hub used in the front wheel of a bicycle.
The hub is the central part in the wheel through which the axis of rotation passes. Features of the behavior of a bicycle depend on its characteristics, in particular, “rolling” (the ability to move by inertia, without pedaling). Knowing the model of the front hub, you can clarify its characteristics according to the manufacturer's documentation, find reviews from other users, etc., in order to determine how this model suits you.
Rear hub model
Model of the hub used in the rear wheel of a bicycle. See Front Hub Model for details.
Speeds
The number of speeds (gears) provided for in the design of the bicycle. Each transfer has its own so-called gear ratio — in this case it can be described as the number of revolutions that the driven gear (rear, on the wheel) makes in one revolution of the leading gear (associated with the pedals).
Different gear ratios will be optimal for different conditions: for example, high gears provide good speed, but are poorly suited for overcoming obstacles, because. the effort on the pedals increases significantly and the frequency of their rotation decreases. It has been scientifically proven that a cyclist develops maximum power at a cadence of about 80-100 rpm. Thus, the presence in the bike of several speeds allows you to optimally adjust it to different driving modes and features of the tracks in order to provide optimal pedaling force and frequency of their rotation. For example, on smooth asphalt it is best to drive in a high gear, and when overcoming a rise or entering a dirt road, you can lower it in order to effectively overcome resistance.
The number of gears in classic systems is directly related to the number of stars of the system (on the bottom bracket with pedals) and the cassette (on the rear wheel); it can be obtained by multiplying two numbers — for example, 3 stars of the system and 6 on the cassette give 18 gears. However, there is also the so-called planetary hubs — there are stars one at a time, and gear shifting is carried out by a mec...hanism built into the rear hub.
Note that the optimal number of gears depends on the purpose of the bike (see above), and it is not always necessary to have several of them. So, in mountain models, depending on specialization, there can be from 8 to 30 gears, in road ones — within 20-30, and some inexpensive city bikes and most BMXs do not have a gear shift system at all.
Chainrings
The number of stars (gears) of different sizes in the bicycle system. The system in this case means a carriage with pedals, which provides the transmission of movement to the chain and from it to the rear wheel. The more stars installed in the system, the greater the choice of speeds (for more details, see "Speeds"), however, for a number of reasons, this number almost never exceeds 3. One star is usually placed on single-speed models; the exception is bicycles with a planetary rear hub, in which the shift mechanism is located in the rear wheel and is not connected to the system.
Freewheel cogs
The number of stars (gears) of different sizes in a bicycle cassette. A cassette is a part of the rear hub that interacts directly with the chain, in other words, a gear or a set of gears mounted on the hub. In classical gear shifting systems, the number of gears directly depends on the number of stars in the cassette (for more details, see "Speeds"); a single chainring is used either in single speed bikes or in planetary hubs (see System Stars for more on these).
Freewheel/cassette model
Model of a cassette — a system of rear wheel gears — mounted on a bicycle. Cassettes of different models differ in characteristics and can belong to different classes — from entry-level to professional. Knowing the cassette model, you can get acquainted with its features in more detail (according to official documentation, reviews, user reviews, etc.). This is especially important when choosing a bike for professional cycling.
Crank model
Model of a connecting rod mounted on board a bicycle.
Cranks is a system of levers that connects the pedals and stars of the front carriage. With its help, the energy of the pressure of the cyclist's legs on the pedals is transmitted. Connecting rods are made from hardened steel, aluminium, titanium or carbon fibre and can be solid or hollow inside. Knowing a specific brand of connecting rod, you can find technical documentation for it or, for example, study reviews on this part on the Internet.
