One of the essential car parts are tyres. It consists of a wheel rim which is surrounded by a rubber-metal pneumatically inflates circular shell.
The tyre creates traction on the surface and also is cushioning road irregularities.
Also, it transmits vehicle load from the axle to the ground. Furthermore, it transmits carload from the axle to the ground.
The main elements of a car tyre are the following elements: tread, nylon, casing and steel belts, sidewall, bead filler, plies, inner liner, bead filler and bundle. Additionally, the tyre can contain a tube This is a torus-shaped balloon made of elastic synthetic rubber aiming to avoid air leakage. In accordance with the presence of tubes, it exits two types of tyres: tubeless and tubeless. Depending on an arrangement of plies inside of the tyre, there are diagonal and radial tyres. Nowadays, most passenger vehicles have radial tyres because of the smaller rolling resistance.
Direction of rotation is another important tyre parameter. For the tyres with a directional tread
pattern, the manufacturer uses marking with an arrow pointing direction of the forward driving rotation. Such tyres should be installed only in accordance with this arrow, otherwise, it will occur a loss of road grip and handling. It exists tyres for trucks and passenger cars, as well as ones for aircraft and bicycles. Truck tyres usually contain tubes, and they are characterized by higher durability, higher load index and different tread pattern.
Each tyre has its tyre code or nomenclature. This is marked on the wall. It includes wheel rim
diameter (written in inches), its aspect ratio and section width, which denotes tyre height in percentage to its width, its type (diagonal or radial).
Usually, this nomenclature includes max speed and load indexes. Besides, these data, tyre wall has producer name on it, seasonal markings, which shows which weather situations the tyre is made for (all-season or winter, for instance).
In addition to the manufacture’s own marks commercial vehicle tyres using two main types of markings on their sidewall. Truck tyres can be designed for drive axle, front steer axle, and carry (trailer) axle, thus are marked as F, D, T or Z, where the Z stands for multi-position (including the front). Additionally, such tyre can also have a marking with max load indexes for twinned tyres or a single wheel.