Frame material
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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.
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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.
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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.Fork material
— 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.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.
Planetary hub
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 other
...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.Shifter type
Type of shifters — devices that control gear shifting — installed on a bicycle. To date, the following types of shifters are used:
— Trigger. The design of this type is based on the use of 1 or 2 levers, as well as (sometimes) buttons located in close proximity to the hands of the cyclist. Trigger shifters can have different designs with varying degrees of convenience (usually, this is directly related to the price category of the device), located above or below the steering wheel, however, a number of common features are characteristic of all such models. Their main advantages are the traditional design and comfort when holding the steering wheel — the shifters are located outside the handles (grips) and do not affect convenience. In addition, they are quite simple in design and installation. On the other hand, this type also has a number of disadvantages. Thus, the presence of protruding parts increases the risk of equipment failure or injury to the cyclist in an accident. In many models, especially the low-cost level, in some cases, you have to take your hand off the steering wheel to change gear, which can lead to loss of control. In addition, shifting gears more than 2-3 "clicks" per press in trigger shifters is somewhat difficult and requires skill. However, in most cases, these disadvantages do not play a decisive role, and this type of levers is by far the most popular.
— Grip shift. By design, the grip shift is somewhat reminiscent of motorcyc
...le gas regulators: part of the handle is made movable, and gear shifting is carried out by turning it in one direction or another. Since the grip shift rings are actually combined with handles (grips), you don’t need to remove your hand from the steering wheel to control the gears — just move it a little to the side, and you can switch speed (and in some cases you can even keep your hands on the rings all the time). Such systems are devoid of protruding parts, which increases reliability and safety. Another advantage over triggers is the ease of shifting gears to any number of speeds. The main disadvantage of this type is the increased risk of accidentally shifting gears on a difficult section of the track, when you have to hold on tightly to the grips (especially with large palms and short grips) — you can accidentally turn the shifter, which is fraught with a sharp shift, breaking the chain from the sprockets and loss of controllability. In addition, contact with water or dirt on the ring can lead to slippage of the hand when working with gears, and the rings themselves increase the dimensions of the steering wheel and for some may cause inconvenience in the grip.
— Dual control. An original system that combines the control of brakes and gears in one lever — the brake lever. In this case, braking is carried out by moving towards you, and gear shifting is carried out by shifting up or down. The advantages of such a system are the constancy of the grip of the steering wheel — 2 fingers are enough to control both the brakes and the gears. At the same time, dual control shifters are quite complex in design, as a result, they are expensive and poorly compatible with “non-native” brakes and switches. And the ergonomics of such systems is very ambiguous, ease of use largely depends on the individual tastes of the cyclist. Therefore, this type of shifters is rather uncommon.
— Electronic. The competitive advantages of electronic shifters include the absence of a cable and levers to transfer physical force to the switch. In fact, these are ordinary buttons that send signals to the gearshift control unit. Such shifters work in conjunction with electronic switches that are installed on board advanced bicycle models. They can be placed in any convenient place with quick and comfortable access to the switches.Shifter model
The model of the shifters (see “Shifter type”) that are fitted to the bike as standard. For more information on why you need to know the model of a particular bicycle component, see paragraph "Cassette Model".
Max range
The maximum range of an e-bike (see "Application") is the maximum distance that it can be ridden using the electric motor on a single battery charge.
Usually, the characteristics indicate the range at the most economical way to use the battery: in the pedal assist mode (see "Operating modes") and at a relatively low speed. Accordingly, in fact, this parameter may turn out to be lower than the claimed one, especially if you drive in full electric mode. Nevertheless, in terms of power reserve, it is quite possible to evaluate and compare various models with each other.
Note that it makes sense to specifically look for a model with a power reserve
of more than 50 km if long trips are planned without recharging along the way. For episodic rides, you can pay attention to cars
with less battery life — they are simpler and cheaper.
Battery capacity
The capacity of the battery that the e-bike is equipped with (see "Application"), expressed in ampere-hours.
The battery capacity directly affects the operating time on a charge and, accordingly, the power reserve. However, in fact it hardly makes sense to evaluate these parameters by the number of ampere-hours. Firstly, the actual battery life will depend not only on the characteristics of the battery, but also on the power of the engine (which determines the power consumption of the machine). Secondly, the actual amount of energy stored in the battery depends not only on the capacity in ampere-hours, but also on the rated voltage; a more reliable unit in this sense is watt-hours, see Battery Capacity below for more details. So when choosing, it is better to focus not so much on the number of ampere-hours, but on the power reserve directly claimed by the manufacturer.
Battery capacity
The capacity of the battery that the e-bike is equipped with (see "Application"), expressed in watt-hours.
The main modern unit of capacity is the ampere-hour, but this designation is not entirely reliable: the actual capacity of the battery is determined not only by ampere-hours, but also by the operating voltage. In fact, this means that two batteries with the same Ah and different voltages will have different actual capacities. In order to take this nuance into account, the designation in watt-hours was introduced: it is as reliable as possible, in terms of capacity in Wh, you can compare batteries with any nominal voltage. In this case, Wh can be converted to Ah and vice versa using a special formula if the battery voltage is known.
See "Battery Capacity" above for details on capacity in general.