Comparison CROSS Evolution 29 2021 vs Author Impulse ASL 29 2023 frame 18

The year to which the manufacturer classifies the bicycle (more precisely, the model range that includes this model).

The significance of this parameter is that the model range is updated every year, and two bicycles with the same name, but from different years, can differ significantly in characteristics and equipment. At the same time, new models ( 2024, 2023) usually cost more, and older ones ( 2022, 2021, etc.) are sold at reduced prices.

It is worth considering that a later year of manufacture in itself does not necessarily mean more advanced characteristics - manufacturers can change them in the direction of simplification. So the model of previous years may be in no way inferior to the new bike.

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 refer to the tables for th...e 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.

The user's height recommended by the manufacturer is calculated according to several parameters. One is the wheel diameter, and the second and more important is the frame size. If everything is simple with the wheel size — it is round and always the same, then the frame size complicates the choice. Different types of bicycles have their own frame shape, so even the same size can be suitable for different heights. And this is not to mention the features of the manufacturer, who like to do everything for themselves, and not in a general manner. Therefore, the size of the frame of each bicycle has its own size and it is still better to choose a bicycle by personally “saddling” it. If this is not possible, then our point will tell you what height, according to the manufacturer, this configuration (frame + wheel) of the bike is designed for.

— Steel. Steel is distinguished by high strength and rigidity, in terms of resistance to deformation, it noticeably surpasses other alloys and is inferior only to carbon fiber. At the same time, such frames dampen vibrations well, are inexpensive, and in the event of a breakdown, they are easily repaired. On the other hand, steel is heavy, three times heavier than aluminium and twice as heavy as titanium; therefore, such frames are found mainly among inexpensive mountain and city bikes, for which a lot of weight is not critical. It is also worth considering that this material is susceptible to corrosion if the protective coating is damaged.

— Chromium molybdenum steel(Cro-Mo). An advanced variation of the steel described above. By themselves, chromium-molybdenum alloys have high strength and reliability, and frames made from them can have different wall thicknesses (depending on the load that a particular section is subjected to) — this allows you to slightly reduce weight. Thanks to this, Cro-Mo alloys are found even among fairly advanced road bikes, and they are also popular in touring models. At the same time, such frames cost much more than “ordinary” steel ones.

— Aluminium. Actually, bicycles do not use pure aluminium, but various alloys based on it. They differ somewhat in characteristics, but they have a number of common features, the main of whi...ch is low weight combined with good strength characteristics. Due to this, aluminium alloys are widely used in road bikes, as well as in touring mountain bikes (see “Intended Use”). The main disadvantage of these materials is rigidity: they absorb vibrations worse than steel, which is why they are poorly suited for models without shock absorption (see below), and with a strong impact, such a frame will break rather than bend.

— Carbon. Resin-bonded carbon fiber composite. It is used in high-end bicycles, as it is very expensive, but it is characterized by very high strength combined with low weight. Moreover, the properties of carbon fiber make it possible to increase strength not just in certain areas, but in certain directions, which contributes to even greater reliability. Note that carbon frames can be either solid (monolithic) or composite — in the latter case, individual elements are connected by metal parts, which reduces the cost, but makes the structure susceptible to corrosion. It is also worth considering that the quality of carbon in general depends on the price category of the bike, and relatively inexpensive frames can be sensitive to strong point impacts. This material is almost impossible to repair.

— Titan. A fairly advanced material that combines high strength, elasticity (which provides soft vibration damping), corrosion resistance and very low weight. However, the cost of such frames is quite high, and therefore they are used mainly in premium mountain and road bikes.

— Magnesium alloy. This material is notable primarily for its very low weight (many times lighter than aluminium), while it has good stiffness and elasticity characteristics, dampens vibrations well, and its price is relatively low. At the same time, magnesium alloys have a number of significant drawbacks. In particular, they do not tolerate impacts, especially point impacts, and are also extremely sensitive to corrosion even with minor damage to the protective coating, which is why such frames are very demanding for care and storage.

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:

— 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.

— 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.

— 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 fork travel on bicycles with damped suspension (see "Suspension"). Roughly speaking, the travel of a fork is the maximum distance that its size can be reduced by compression during shock absorption. The longer the fork travel, the better the shock absorption and “soft” ride it provides, but not all bikes require a lot of travel. Even within the same type (see “Purpose”), depending on the specific application and riding style, the optimal fork travel will be different — for example, freeride mountain bikes need good shock absorption, and for cross-country, on the contrary, a long fork travel will be redundant.

In general, if you do not plan on extreme cross-country riding or doing cycling tricks, this parameter is not critical. However, when choosing a bike for serious cycling, it is worth checking the recommended fork travel values (according to specialized literature or from professionals) and making sure that the desired model corresponds to them.

Possibility to disable the shock-absorbing system of the front fork (if available, see "Suspension"). Although shock absorption dampens shock, providing ride comfort, it also has a rather serious drawback — it reduces the efficiency of transferring energy from the pedals to the wheel. By disabling damping, you can significantly increase efficiency in conditions where vibration dampening is less important than good pedaling efficiency — for example, when driving on a flat road, or when driving uphill.

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.

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.