Wheel size
The nominal diameter of the bicycle wheels. Usually, this paragraph actually indicates the size of the bicycle tyres supplied in the kit, more precisely, the outer diameter of the tyres.
Wheel diameter is traditionally indicated in inches. For bicycles of different purposes and age groups (see paragraphs above), there are certain size standards. So, adult mountain models are equipped mainly with
26 " wheels, "road" and urban ones — with a slightly larger diameter (mostly
28 "), and BMX for the most part — much smaller; children's and teens' bikes have smaller wheels than similar adults' bikes.
Other things being equal, larger tyres hold speed better and work out small bumps on the road; and relatively small wheels are more “sticky”, they provide more torque and better traction. This is the reason for the above-described difference in wheel sizes between bicycles for different purposes. Such nuances will be useful if you choose a car from several models with similar characteristics, but different wheel diameters. Here it is worth considering the features of the planned application. For example, for urban and "road" driving — on a hard surface without any special irregularities and elevation changes — it is better to choose larger wheels, and for dirt roads with ups and downs — smaller ones.
Also note that tyres are replaceable, and many bikes allow the installation of tyres of
...a “non-native” size — for example, 29 "on a model with 28-inch wheels. It is also worth considering that wheels (tyres) of the same size may differ in inner (landing) diameter These nuances are described in detail in special sources.Tyre
Tyre model supplied with the bike as standard. Different tyres have different purposes and characteristics; knowing the tyre model, you can clarify these points and check how they correspond to your wishes. This is especially important when choosing a machine for serious cycling.
Rim
Varieties of rims are determined by the number of horizontal jumpers in the design.
— Single. The simplest type of rim, similar in cross section to the Latin letter U. It is used mainly in entry-level bicycles.
— Double. Such a rim differs from a single rim by the presence of an additional horizontal bridge. Figuratively speaking, it resembles the same letter U, but with a double bottom. The features of this design are such that it is able to provide increased strength even with less weight than a single one. On the other hand, double rims are more difficult to manufacture and therefore more expensive. They are used primarily in bicycles where high resistance to stress is required — in particular, mountain varieties (see "Intended use") for freeride and cross-country.
— Triple. A further development of the idea of a double rim is a design with two additional horizontal bridges. This provides even greater strength, however, the weight increases quite noticeably. In addition, initially the second jumper was provided to strengthen the side surface, in order to avoid damage during the operation of rim brakes (see "Front brake", "Rear brake"); however, today most powerful brakes are
disc brakes, and this problem is losing its relevance. Because triple rims are quite rare.
Front brake
The type of brake fitted to the front wheel of a bicycle. The first word in the name of the brake indicates the place of application of the braking force, the second — the design feature of the entire braking system.
—
Rim (V-brake). Rim brakes are called brakes that work by pressing the brake pads against the wheel rim. They transfer the braking force from the handle to the pads by means of a cable pull. The common advantages of all rim brakes are the simplicity of design, light weight, low cost, good interchangeability of parts, as well as the minimum load on the hub and spokes. On the other hand, such brakes wear out the pads and rim, require periodic adjustment, and lose effectiveness when the rim is dirty, iced or warped.
Structurally, the differences between the subtypes of rim brakes lie in the way they are attached to the bicycle frame. In addition, each variety has found its own scope. So, V‒brake is common in teenage, touring and budget mountain bikes, the clamp subtype has found its way into road and city bikes, and the U-brake is practiced in BMX bikes.
— Disk mechanical. In disc systems, braking is carried out by pressing the pads not to the wheel rim, but to a special brake disc rigidly fixed on its axis. The braking force, as in mechanical rims (see above), is transmitted to the pads through a special cable. The main advantages of disc systems are significantly more power than rim systems, as we
...ll as better modulation (for modulation, see "Rim hydraulic" above). In addition, they are less sensitive to weather conditions (because the disc is quite high and clogs less than the rim), they easily carry the “eights” on the rims, and the elements of the system wear out more slowly and are not so demanding to adjust. Among the disadvantages are greater weight, high cost, a tendency to overheat, an increase in the load on the spokes and wheel hub, as well as difficulty in repair — the last point is aggravated by the fact that different models of even one manufacturer are often not compatible in terms of spare parts. However, despite all this, disc brakes are quite widely used in extreme riding bikes, especially mid-range and high-end models.
— Disc hydraulic. A variant of disc brakes (see above), in which not a cable is used to transfer force from the handle to the pads, but a hydraulic system — a sealed structure filled with liquid and including a piston system. One of the main advantages of hydraulics is excellent modulation, it allows you to very accurately control the braking force. On the other hand, such a drive is more complicated and more expensive than a mechanical one, and if the circuit is damaged and the hydraulic fluid leaks, the brakes become useless. Therefore, hydraulic systems are used relatively rarely, mainly in professional bicycles.
— Drum. Brakes using a special drum, inside which brake pads are installed; in bicycles, the role of the drum can be played directly by the wheel hub or a special part of the hub. Anyway, the pads are pressed against the drum from the inside, and the entire brake structure is closed. This is one of the main advantages of this option: the mechanism is protected from pollution, external factors such as dirt or snow practically do not affect the effectiveness of the brakes. In addition, the advantages of drum mechanisms include the fact that they practically do not require maintenance, do not wear out the rim and do not lose efficiency when it is bent. On the other hand, such brakes turn out to be quite bulky, and in terms of efficiency they are inferior to rim and even more so disc counterparts. Therefore, this option is found mainly in urban bikes.
— Roller. A variety of drum brakes (see above), in which the pressing of the brake pads to the drum is ensured by a special mechanism — roller. In this case, the brake drum is often performed separately from the bushing. Such solutions were developed as an attempt to combine the advantages of disc and drum brakes in one mechanism, and partly succeeded: roller systems are noticeably more powerful than classic drum brakes, they are well protected from dust and dirt, require virtually no maintenance and work effectively even with a curved rim. On the other hand, the weight, dimensions and price of such brakes turned out to be very significant, they worsen the roll and get quite hot with constant use; and protection against pollution is not as high quality as in drum systems.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.
Bottom bracket model
Model of the carriage installed on the bike as standard. The bottom bracket is the part that connects the system (front sprockets with pedals) and the frame; roughly speaking — an axle with bearings.
For details on the meaning of the model of a particular part, see "Cassette Model".
Chain model
Model of the chain supplied as standard with the bike. For details on the value of the Model parameter for any part, see Cassette Model
Equipment
Additional equipment supplied with the bike.
—
Wings. Protective devices in the form of shields that are installed over the wheels and protect the cyclist and others from water and dirt flying from the wheels while riding. Usually, they are made removable — in case you need to minimize the weight of the car.
—
Saddle with springs. A saddle equipped with springs that make it softer and provide cushioning. Note that soft spring-loaded saddles are designed mainly for a calm, leisurely ride — for high-speed bikes (including advanced road bikers), narrow hard saddles are considered more suitable.
—
Shield on the chain. Protective shield covering the bicycle chain. Note that the dimensions and design of such a shield can be different: in some models it covers the entire upper section of the chain from the front to the rear sprocket, in others it protects only the front sprocket itself from the outside. Anyway, the main task of such a device is to protect the chain from foreign objects, primarily the edges of the cyclist's clothing. The shield can be made removable — in case you need to reduce weight.
—
Footboard. A device in the form of a small folding pin that provides additional support. With a footrest, the bike does not need to be leaned on a pole, wall, fence, etc. — it can be placed vertically on an
...y relatively flat surface. Note that many bikes without a kickstand allow you to buy and install it separately.
— Peggy. Special devices installed on the axles of "stunt" bikes — BMX or mountain bikes of the corresponding specialization (see "Application"). Pegs look like extensions of axes pointing in both directions. The standard size of one such "continuation" is 11 cm in length and 4 cm in diameter. They are used for a variety of acrobatic routines, ranging from riding on pegs to sliding on edges, railings, etc.
— Boot. A classic bike rack is a platform for carrying various cargoes, mounted above the rear wheel. It is found mainly in city bikes (see "Application"), as well as some relatively simple mountain and road models. Separately, we note that it is at least highly discouraged to carry passengers on the boot, and in many countries it is expressly prohibited by traffic rules.
— Front boot. Boot (see above), located above the front wheel. The advantage of this arrangement is that the transported luggage is constantly in front of the cyclist's eyes. On the other hand, the front rack is usually attached to the steering wheel and turns with it; thus, the additional load can significantly complicate management. Therefore, this feature is relatively rare, usually as an addition to the traditional (rear) boot; the exception is tourism models (see "Application").
— Basket on the steering wheel. A basket for transporting various goods, installed in front of the steering wheel, above the front wheel; a kind of analogue of the front boot described above. At the same time, on the one hand, the basket is more massive, on the other hand, it is better suited for transporting large items or numerous small items. In addition, the cargo on the boot needs to be additionally secured, while this is not always required for the basket.
— Signal / call. A bell or other sound signal — for example, a horn — usually mounted on the steering wheel, at the cyclist's hand. This equipment is very useful for warning other road users of an approaching bicycle. And in some countries, the presence of a sound signal is mandatory according to traffic rules.
— Lighting equipment. In this case, the presence of a headlight, a taillight, and in some cases, both at once, may be implied; specific configuration should be specified separately. Anyway, such equipment is indispensable for riding at night: it makes the cyclist visible to other road users, and the headlight also illuminates the road. In many countries, traffic rules expressly prohibit driving at night without lights.
— Bottle holder. Dedicated water bottle holder, usually mounted on the frame. It is more convenient to carry a supply of water with you on such a mount than to keep a bottle in a backpack, bag, on the boot, etc. Some bike models with this function are immediately equipped with a bottle, for others it needs to be purchased separately.
— Pump. The presence of the pump in the delivery set eliminates the need to buy it separately; in addition, the “native” pump initially fits the existing mounts, while problems may arise with a third-party one. Note that most often the kit comes with relatively simple and compact hand pumps; they are not designed for large volumes of work, but they can quite cope with everyday tasks like pumping a flat tyre.