Adapted to vehicles weighing over 3.5 tons, a truck tyre should offer robustness, endurance and savings on fuel.
A truck tyre is first and foremost a safety feature which bears the load and ensures driving stability and vehicle handling.
A tyre for every use
Not all tyres are designed for the same use and not all tyres in the same category have the same characteristics. Although this may seem obvious, this simple concept represents one of the key components contributing to operating costs. Using the right tyre for the right purpose can result in substantial financial savings and ensures the safe transportation of people and goods. In other words, buying a more expensive, top quality tyre is only the right choice if it is used for the purpose for which it was designed by the manufacturer.
A tyre is not just a ring of moulded, sculpted rubber. From the initial design right through to manufacturing, tyre production requires the use of high tech materials and techniques which, when used together, determine the tyre’s structure and function.
Producing a tyre is a bit like making puff pastry. Whilst on the outside all you can see is rubber, that rubber is in reality made up of around ten layers of different materials, which together allow the tyre to respond to specific stresses.
Truck tyre components
1. Tread strip
This is the part of the tyre made from moulded rubber which stays in contact with the road surface and has greater or lesser resistance to wear depending on the chemical make-up of the rubber.
2. Multi-ply belt
Layers of metal strips which ensure the tyre’s rigidity when cornering and contribute to driving stability.
These are the side sections of the tyre where the markings can be found and which bears the strain induced in motion or on impact. The sidewall may be equipped with an anti-spray feature.
4. Carcass ply
This arched ply, situated between the rubber and the crown, is made up of parallel steel wires in a radial position (hence the term radial tyres). It provides and maintains the tyre's lateral strength by stabilising the tread surface in contact with the road.
The inner-lining is the layer of synthetic rubber inside the tyre which ensures air tightness instead of an inner tube.
6. Bead wires
Located on the bead at the base of each sidewall, the bead wires have three functions: These metal wires anchor the tyre to the rim, shift torque from the wheel to the tyre and prevent air from escaping through the rim.
Located in the tyre bead, this is a triangular piece of hard extruded rubber situated above the bead wires which serves to strengthen the sidewall.
8. Bead reinforcement
Rubber component which strengthens the bead and avoids overheating in the event of serious under-inflation or a puncture.
9. Bead strip
Protects the bead components
In tyres with an inner-tube, it is also important to fit a flap. This layer of rubber or metal stops the rim from rusting and the tyre from coming off the rim when under-inflated.
By varying the parameters for each of these layers, the manufacturer can produce tyres which are capable of responding to a given situation or another. It is therefore essential to properly define the characteristics required in order to choose the best tyre for the job and reduce operating costs.
By Alexandre Lenoir