Comparison ADO A20+ 360Wh vs Xiaomi MiJia QiCycle

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.

The presence or absence of a depreciation system on a bicycle, as well as the type of this system.

— Without depreciation (rigid). In such models, the wheels are fixed directly to the rigid elements of the frame; there are no depreciation devices. Due to this, the design of the bicycle is simple, the weight is small, the cyclist feels all the features of the road topography as much as possible, and the maximum efficiency of pedaling is also achieved, which is important, for example, for road models (see "Destination"). At the same time, structural rigidity is a "double-edged sword". On the one hand, "feeling for the road" is important for BMX and some mountain models (see "Purpose"); on the other hand, the lack of shock absorption significantly increases the load on both the structure and the rider himself, leads to increased wear, fatigue and some risk of injury on rough roads.

— Depreciation of the front fork (hard tail). The most popular type of cushioning in adult bikes (see "Age Group"), especially urban and mountain types (see "Purpose"). In accordance with the name, in such bicycles, the shock-absorbing device is installed only on the front fork, while the rear wheel is rigidly fixed. The presence of a shock absorber somewhat increases the weight of the structure and complicates its maintenance, however, the advantages of such a scheme significantl...y outweigh the disadvantages: hard-tails combine good handling, “road feel” and ride comfort, including and on rough terrain.

— Rear fork. Bicycles in which only the rear wheel is damped, while the front wheel is rigidly fixed. The rear shock absorber is designed to provide additional comfort when hitting various bumps, and the absence of a front shock absorber reduces the overall cost of the machine. This option is found mainly in urban models, including electric bicycles (see "Application"); in other varieties, the use of rear shock absorption is not practical.

— Two-suspension (full suspension). Bicycles equipped with shock absorbers on both wheels — a fork in front and a special suspension in the back. Such models are as comfortable as possible for driving on rough terrain, because. They dampen the vibrations felt by the cyclist best and provide the best grip on uneven tracks. At the same time, the presence of a rear shock absorber "eats" part of the energy coming from the pedals, and you have to spend more effort to ride. To avoid this, many two-suspension bikes can be provided with front and rear suspension lockouts (see below), but full suspension complicates the design anyway, increases its weight and price. Therefore, this type of cushioning is relatively rare, mainly in certain varieties of mountain bikes (in particular, for cross-country and freeride; see "Purpose").

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.

— 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.

The presence in the design of the bicycle of a separate shock absorber under the saddle. The seatpost cushioning significantly reduces the vibration and shock felt by the rider, which is especially important when riding on uneven terrain.

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.

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.

Light-alloy wheels of a monolithic design, cast in special moulds from aluminium, less often from titanium. Bicycles with alloy wheels are characterized by increased resistance to oncoming air flows, strength and durability, and aesthetic appeal. At the same time, alloy wheels are less resistant to side gusts of wind, have poor maintainability and are very expensive. Alloy wheels are found mainly on board city and road electric bicycles, also specialized racing bike models are equipped with alloy wheels.

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.