FAQ

Tyres for heavy vehicles - tractors, trucks or construction machinery - are usually very expensive. This is because they have to endure a huge load and work in very difficult conditions. Unfortunately, despite the fact that such tyres are made of very durable materials, after some time they are exposed to damage. Fortunately, the damaged tyre does not have to be discarded. It can be repaired so that it regains full fitness.

Tyres for special tasks
Tires for heavy goods vehicles are characterized by a specific construction - it is necessary to withstand heavy truck loads. Such tyres are designed for vehicles with a weight exceeding 3.5 tonnes. In their case the most important thing is durable construction and durability. Properly selected tyres also allow you to save fuel. They are to guarantee their users safety and allow comfortable driving in any situation.

Construction of tyres for trucks
Truck tyres consist of many different components - each one must be of excellent quality:

The tyre is a product consisting of various materials and rubber components whose properties ensure proper use. Tyre properties change over time. The degree and speed of wear depends on the storage conditions (temperature, air humidity, tyre placement, etc.) and conditions of use (load, speed, pressure, damage, etc.) that affect the tyres throughout their lifetime. The coexistence of so many factors makes it impossible to precisely determine the durability of tyres. That's why we encourage drivers to regularly check their tyres by a professional tyre dealer who will assess whether the tyres are suitable for further use.

Tyres used for at least 5 years should be checked at least once a year, as well as tyres 8 years after the production date. Tyres of 10 years or more are not recommended for use on truck axles and buses. We recommend mounting such tyres on trailing axles.

The effect of tyre pressure on driving efficiency
When the amount of air in the tyre drops significantly, the driver feels a change in the quality of driving and often only then he decides to control the tyres. However, it is not worth waiting for this critical moment. A perceptible pressure drop is a sign that the tyres are already very weak. It is equally dangerous to make the tyre pressure too high. Riding on tyres with the wrong pressure irretrievably destroys the tyres, negatively affects the suspension and steering. Bad pressure also affects high combustion and driving safety

Why is the tyre pressure so important?
Correct tyre pressure helps to better distribute the weight of the car on the tread, which directly translates into stability and driving safety. When the tyre is too heavily or too weakly inflated, it loses stability and negatively affects such important factors as: cornering, braking line length, vibrations on the steering wheel while driving. Too low pressure is visible after significant tread wear at the outer edges of the tread. Too high pressure in the tyre indicates high wear of the central tread

Risk associated with bad tyre pressure
The under-inflated tyre is very flexible in the vertical axis of the tread-rim, which significantly affects cornering and braking length. Such a tyre does not react as fast as it is properly inflated, thus its efficiency drops dramatically compared to the parameters assumed by the manufacturer. This, in turn, directly translates into driving safety. Tyres, in which the pressure is higher than recommended, have big problems with adhesion and traction, due to the deformation of the tyre shape, affecting the points of contact between the tread and the surface. In this case, the only part of the contact is the middle part of the tyres - thus the efficiency of heat or water discharge from under the tyre drops significantly. Tyres whose pressure is not correct are much more susceptible to damage caused by poor quality of the surface. In both cases - too low or too high pressure - any unevenness can cause too much stress in the tyre structure. This is caused by a sudden change in the distribution of air molecules within the tyres. The tyre is then much more exposed to an explosion or the appearance of deformation.

How to check tyres?
The tyre pressure should be checked once a month. In addition, it is recommended to check the condition and air pressure inside the tyres before each journey exceeding 80 km. To assess the level of air in the tyre you will need to use a professional device - the measurement can be done in a car workshop or at a petrol station. It is impossible to say whether the tyres are too heavily or too weakly inflated, checking only the condition of the tread surface. Examination and checking the amount of air should take place when the tyre is cool.

In most European countries, the legally permissible minimum tread depth for commercial vehicles is 1.6 mm. The recipe is clear, but fleet managers, drivers and even the authorities themselves do not always know where to measure the tread depth of the truck and bus tyres. In addition, measurements made by the road are often questioned

The right tread depth is a very important element that decides about allowing the vehicle to move. In Europe, trucks are often stopped for control, during which not only the hours worked by the driver, but also the condition of the tyres. In most European countries, the minimum permissible tread depth is 1.6 mm. In the case of tyres that do not meet this requirement, you should expect a high mandate and / or not allow the vehicle to continue to move. It is worth noting that this can also happen when the tread depth is measured incorrectly.

What does TWI mean?
Measuring the tread depth of the truck should, however, be unambiguous. The tread must be measured in the main grooves of the tyre, as indicated by the manufacturer. Unfortunately, not all fleet drivers and managers always know which grooves are going, which causes incorrect measurements. The majority of manufactured truck and bus tyres are equipped with Tread Wear Indicators (TWI), which help measure the remaining tread depth. They are small protrusions, 1.6 mm high, placed in its main grooves. Small arrows on the side wall indicate the position of the indicator. When the projection of the indicator is flush with the surface of the tyre, the remaining tread thickness is 1.6 mm and the tyre should be replaced.

When driving, a tyre with a load capacity lower than the vehicle load or excessively loaded will overheat which can lead to damage and sudden pressure loss in the wheel. The contact area of ​​the tyre with the ground may not have the right shape, which will have a negative effect on the vehicle's behavior and tyre grip when driving and braking.

Tyre incorrectly selected in terms of conditions of use may: - overheat: in the case of universal tyres used on motorways and long distances, - be destroyed: in the case of tyres with tread pattern developed for driving on roads over long distances but used on unpaved surfaces. In the above cases, the tyre with visible damage must be examined by a specialist, who will determine if it is possible to continue using it, or whether it is necessary to repair or disassemble the tyre. It should be noted that exposed fragments of belts or carcass tyres will be exposed to corrosion - the use of a tyre with such damage is a violation of the provisions of the Highway Code. This type of damage leads to rapid destruction of the tyre while driving and may run the risk of sudden pressure loss in the wheel. Tyre wear may prevent retreading.

A tyre not intended for a driving axle or not suited to the conditions of use may, depending on the condition of the road and speed, reduce the precision of driving. The tyres on the front axle are the first to come into contact with the surface. Therefore, they are adapted to provide gradually information on changing road surface conditions, for example by reducing traction. A tyre that is not adapted to this position, such information about changing the surface may carry irregularly or to a very limited extent. Uniform tyre behavior is particularly important at the driving axis (direct connection to the steering wheel, position under the driver's cab, etc.). The tread patterns on the guide axle are designed to meet this criterion. Tyres that are not intended for the driving axle will not meet the specified conditions required for this position. In the moment of sudden braking a clear load is shifted to the guide axle, which is why the tyres on the guide axle play a key role in the total braking distance of the vehicle. The braking properties of tyres that are not adapted to the guide axis may be limited in the case of assembly in this position. Decreasing the speed with the engine (retarder) has a strong influence on the tread and casing of tyres on the drive axle. As a result, improper tyres in this position may be less effective in transferring braking power, and therefore their service life may be shortened. The tyres on the drive axle are the only ones that transmit the torque in contact with the road. For this reason, poorly matched tyres in this position may be less effective in transmitting the acceleration force, and therefore their service life may be shortened. The tyres must be adapted to the position in the vehicle and the type of use. In the event of non-compliance with this rule, they can not achieve the optimal mileage.

Truck tyres significantly affect the fuel consumption of vehicles. The selection of the right tyre with the right tread design plays a key role. For some applications it is possible to optimize fuel consumption by installing tyres with low rolling resistance. The more tyres are worn out, the lower their rolling resistance. Replacing a tyre that has not yet reached its full level of wear prevents its maximum potential from being used in terms of fuel economy.

LOAD INDEX (load index) – is a numerical code indicating the maximum load with which the tyre can be used, when driving with the maximum speed permitted by the tyre manufacturer. The permissible load values ​​given in the instructions always refer to the maximum payload for one tyre.

The tyre speed index must always be in accordance with the vehicle manufacturer's indications and with the maximum load capacity index.