Comparison Marin Presidio 1 2023 frame L vs Marin Kentfield 1 2023 frame L

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.

— 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.

In this case, we mean the French marking of the size of bicycle tires. It is recorded in the “700x35C” format. The first number determines the outer size of the tire in millimetres, the second — is the width of the tire, and the letter of the Latin alphabet from “A” to “D” indicates the internal (landing) size. “A” is the smallest size, “D” is the largest. The marking is found on tires for road, hybrid and city bicycles, but tires for mountain bikes are not marked with it.

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.

Model of the brake used on the front wheel of a bicycle.

Knowing a specific brand of brake system components, you can find technical documentation for it or, for example, study brake reviews on the Internet. For more information about the types of brakes on the front wheel, see "Front brake".

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 dif...ficulty 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.

Model of the brake used on the rear wheel of a bicycle.

Knowing a specific brand of brake system components, you can find technical documentation for it or, for example, study brake reviews on the Internet. For more information about the types of brakes on the rear wheel, see "Rear brake".

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.