Comparison VNC Emily AC 24 2019 vs Pride Sophie 4.2 2019

Frame size refers to the distance from the saddle attachment point to the bottom bracket attachment point (axles with gears and pedals). The main parameters that determine the choice of a bike for frame size are the height of the user, the purpose of the bike and the intended riding style.It is also worth considering the female frame, which is lowered, which allows you to ride comfortably even in a skirt or dress.

User height is the most significant factor. In general, the taller the user, the larger the frame should be. The universal formula that allows you to calculate a specific size is as follows: the length of the leg from the groin to the heel in centimeters must be multiplied by 0.6, and then divided by 2.5 — you get the approximate size of the frame in inches. But in the characteristics of brands, the frame can also be indicated in the usual form for measuring size XXS, XS, S, M, L, XL and XXL.

However, note that this value is very arbitrary and approximate, it can only be used for simple bicycles not intended for extreme driving (for example, city bikes, see "Destination"). If you choose a more specialized model (mountain, road, BMX) — it is better to re...fer to the tables for the appropriate type, because. sizes for one height can vary significantly depending on the destination. In addition, different manufacturers have different frame geometry and measurement methods, and therefore, for the most accurate selection, it is recommended to use the manufacturers' own tables.

Note that the optimal frame size is not absolute — in most cases, for the same height, “neighboring” sizes are quite suitable. And here it is worth paying attention to the intended driving style. It is believed that small, well-controlled frames are better suited for extreme variant, and larger and more stable ones are better suited for long-term calm movement.

— Aluminium. In this case, aluminium is the simplest and most unpretentious option. Its advantages include light weight; on the other hand, in the absence of shock absorption, the steering wheel with such a fork is highly susceptible to vibrations, and in terms of durability, aluminium is somewhat inferior to steel.

— Steel. Another relatively simple option, which at the same time is considered more advanced than the aluminium described above, and is found even in fairly expensive pro-level bikes. This is due to the fact that steel is noticeably stronger and more durable, as it is not as susceptible to "metal fatigue". However such forks weigh a little more than aluminium ones.

— Chromium molybdenum steel. A type of steel that is more advanced than more traditional grades. Among the main advantages of such alloys are high strength and reliability; at the same time, due to such properties, individual elements of the forks can be made thinner, and the forks themselves can be made lighter than ordinary steel ones. The main disadvantage of Cro-Mo steel is the rather high cost.

— Carbon. Lightweight and high-strength carbon fibre forks effectively dampen small bumps in the road under the wheels of the bike and slightly spring on small potholes, thereby providing cushioning on bumpy roads. The carbon fork facilitates the design of the front of the bike. Most often it is found on board "highways" and "gravel roads", less often it is installed in o...ff-road fatbikes. Vulnerable point — carbon forks break under the influence of strong point impacts.

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.

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.

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.

Model of the hub used in the rear wheel of a bicycle. See Front Hub Model for details.

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.

The presence of a planetary hub in the design of a bicycle, more precisely, the rear wheel of a bicycle.

Such a bushing is installed directly on the wheel axle; the name "planetary" describes the type of mechanism located inside. The purpose of such a sleeve is the same as that of the cassette (see below) with several sprockets: it provides gear shifting. At the same time, the cassette itself most often has one asterisk and does not participate in gear shifting (although there are exceptions where the “planetary” is supplemented by a cassette with several asterisks).

The planetary hub has both advantages and disadvantages compared to the classic multi-star cassette. One of the key advantages is the closeness of the mechanism: it is not affected by moisture and pollution, requires virtually no maintenance and, subject to the rules of use, can last a very long time. If gear shifting is carried out only due to the “planetary”, the bike does not need additional rollers for the chain and it wears out less. Also, the chain in such models is constantly in one position, which allows you to install full protection on it (and it protects not only the chain, but also the cyclist's clothes). In addition, the advantages of planetary bushings include ease of adjustment, resistance to falls on the side, ease of adjustment, ease of switching (one switch is enough) and the absence of close and “opposite” gears.

On the ot...her hand, such systems are much more expensive and heavier than classical switches of similar quality; they are more difficult to repair, make it difficult to replace the wheel and adjust the gear ratios if the initial value of the latter for some reason does not suit the cyclist. Yes, and the gear ratio (the difference in speed between the lowest and highest gears) of the planetaries is noticeably lower; the exception is perhaps expensive professional bushings, and even then not all. This makes climbing steep hills difficult (the gear may not be low enough) and fast driving, where high gears are needed, including when descending. Accordingly, planetary hubs are poorly suited for hilly or rough terrain. However, the gear ratio can be increased by adding a classic derailleur (with a multi-star cassette) to the bike — however, with this addition, many of the original advantages of the "planetary" are lost, such as insensitivity to pollution and a constant position of the chain.

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.