Comparison Comanche Tomahawk 29 frame 17.5 vs Comanche Niagara 29 Disc

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.

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 developmen...t of “pure” 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.

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.

— 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 model of the seatpost used in the bicycle.

Usually, this information is indicated if a high-quality part is used as a seat post. Knowing the name, you can find its detailed characteristics and descriptions; this is unlikely to be needed for light everyday driving, but may be useful for professional use.

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...well 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.

A type of rear brake fitted to a bicycle. Here are the main types of brakes found today:

— Obodnoy. Rim brakes are those that work by pressing the brake pads against the rim of the wheel. They transfer the braking force from the handle to the pads via cable traction. The common advantages of all rim brakes include simplicity of design, light weight, low cost, good interchangeability of parts, as well as minimal load on the hub and spokes. On the other hand, such brakes wear out the pads and rim, require periodic adjustments, and lose effectiveness if the rim becomes dirty, icy, or bent.

Structurally, the differences between the subtypes of rim brakes lie in the way they are attached to the bicycle frame. Moreover, each variety has found its own area of application. Thus, V‒brake is common in teenage, recreational and budget mountain bikes, the pincer subtype is used in road and city bikes, and U-brake is practiced in BMX bicycles.

— Disk mechanical. A kind of mechanical brakes (see above), in which the pads are pressed against a special brake disc (rotor) rigidly fixed to the wheel hub during braking. Such brakes are much more efficient than rim brakes, they are not as sensitive to dirt and retain their full performance even with rim curvature. Among the disadvantages of disk systems, one can note greater weight and cost, increased load on the bushing and spokes, as well...as difficulty in repair.

— Disc hydraulic. Disc brakes (see above), in which the force on the pads is transmitted not by a cable, as in mechanical systems, but by means of a hydraulic circuit. They are the most advanced option in terms of performance: the use of a disc provides high braking efficiency, and the hydraulics give excellent modulation and allow you to accurately dose the force on the handle. At the same time, such systems are not cheap, and in addition to the general disadvantages of disc brakes, they add sensitivity to damage: a violation of the tightness of the circuit leads to fluid leakage and brake failure.

— Drum. Brakes in which the pads are pressed from the inside to a special drum; in this case, the role of this drum is usually played directly by the wheel hub. One of the advantages of such systems is that almost the entire mechanism is hidden inside the drum and protected from dust and dirt, making it virtually maintenance-free. In addition, drum brakes do not wear out the rim and can work even with a bent wheel. On the other hand, such systems are rather bulky and their effectiveness is lower than that of rim and disc brakes. In addition, the drum brake on the rear wheel can be used with either a single speed cassette or a planetary hub (see below) — these brakes are not compatible with classic multi-star cassette derailleurs.

— Roller. A variation of the drum brakes described above, in which the pressing of the pads to the drum is ensured by the so-called. roller mechanism. The drum in this case, usually, is performed separately from the sleeve. Due to this, it was possible to achieve higher efficiency (comparable to disc brakes) while maintaining the main advantages of the drum circuit — unpretentious maintenance, good protection against dirt and independence from rim curvature. However, roller brakes are not cheap, and besides, they have a number of their own drawbacks — in particular, they worsen the roll and make it possible to spin the wheel back when the brake is pressed. Yes, and with classic speed switches, such systems are poorly compatible.

— Pedal. In fact, it is a variation of the drum brake described above, controlled not by a handle, but by pedals: braking is carried out by pressing the pedals in the opposite direction. This method of control greatly simplifies the design, eliminating unnecessary handles and rods. At the same time, in some moments it is not very convenient and practical. So, the effectiveness of the brakes is directly dependent on the position of the pedals — for maximum efficiency, they must be horizontal at the time of braking, and in a vertical position, difficulties may arise. In addition, when the chain falls off, the cyclist, in fact, loses the brake. Thus, pedal mechanisms are used relatively rarely — mainly in city bikes that are not designed for particularly high-speed riding.

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.