Comparison Merida Big.Nine 15 2023 frame L vs Trek Marlin 7 Gen 2 29 2023 frame L

The maximum load allowed for a bicycle is, in other words, the maximum weight that it can normally carry in normal use. Of course, when calculating the load, the weight of both the cyclist himself and the additional load that he carries with him is taken into account.

The permissible load must definitely not be exceeded: even if the bike does not break down immediately, off-design loads can weaken the structure, and an accident can occur at any time. Also note that it is desirable to have a certain weight margin — at least 15 – 20 kg: this can be useful in case of transporting heavy loads and will give an additional guarantee in emergency situations (for example, when a wheel gets into a pit). Considering that the average weight of an adult is about 70 – 80 kg, bicycles with a permissible load of up to 100 kg can be classified as "lightweights", from 100 to 120 kg — to the middle category, more than 120 kg — to "heavy trucks".

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.

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.

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.

Front rotor.

The front disc brake rotor is a perforated metal plate attached to the wheel hub. The reduction in speed of the bike occurs as a result of the compression of the brake disc by the pads, which are driven by cable tension (in mechanical type systems) or by means of a hydraulic circuit (in hydraulic disc brakes). The diameter of the front rotor can vary from 140mm to 220mm. The higher the number, the more efficient the brake is.

Rear rotor.

An element of a disc brake system mounted on the hub of the rear wheel of a bicycle. It is to him that the pads are pressed when the brake lever is pressed. The use of a rotor ensures high braking efficiency. And it is higher, the larger the diameter of the rear rotor. Disc rotors are available in sizes 140, 160, 180, 185, 203 and 220 mm.