Your tyre’s rubber blend can feature up to 30 separate ingredients, with different proportions affecting the performance characteristics of the tyre. During the blending process, rubbers, fillers and other essential ingredients are mixed together to create a black, sticky compound that is then ready to be milled.
The cooled-down rubber blend is cut into strips at a special mill. These strips will form the basic structure of the tyre. Other parts of the tyre are also prepared during the milling process, some of which are coated in a different type of rubber.
During the building stage the tyre is constructed from the inside out, with the component parts - textile elements, beads, steel belts, ply, tread, and other parts - placed in a tyre-building machine that ensures every part is in the right place. The end result, know as a ‘green tyre’, looks close to completion.
The green tyre is ‘cured’ in a vulcanizing machine. This machine uses hot moulds to compress the component parts together. The tyre is given its final shape during the curing stage and is stamped with its tread pattern and sidewall markings.
All Sava tyres are thoroughly inspected before they are ready to be shipped to dealers. The inspection process involves visual checks by trained experts as well as mechanical tests that will identify even the slightest fault or potential weakness. A selection of tyres will undergo X-ray checks that pick up the slightest internal problem. Other tyres will be randomly selected from each batch and cut open by quality control engineers to ensure their construction meets our high standards.
Ply: Your tyre’s internal ‘skeleton’ consists of layers of fabric called plies, which are made of a rubber-coated textile weave. Ply construction enables tyres to be flexible, but prevents stretching. Much of the tyre’s strength comes from a robust layer of ply – called the ‘carcass ply’ – next to the inner liner of the tyre.
Beads: Beads create an airtight seal between your tyre and the wheel rim. They are created from strong braided steel and are coated in rubber.
Belt: Your tyre’s strength is reinforced by steel belts – woven sheets of steel wire, coated in rubber - which add rigidity. Some tyres feature the addition of Kevlar cord to the belts for extra strength, longer life and resistance to damage.
Sidewall: The part of your tyre between bead and tread. Your tyre’s sidewall is made of thick rubber, which boosts the tyre’s lateral stability. All tyre sidewalls are also stamped with essential information about the tyre, including sizing, performance characteristics and recommended inflation.
Shoulder: The beveled edge where the tread joins the sidewall is known as the tyre shoulder. Shoulder design is an important factor in a tyre’s cornering performance.
Tread: The wide area of softer rubber that is in contact with the road, and provides a tyre’s grip and cushioning. Tread pattern design and the rubber compound used in its construction are two of the most important factors in determining how each tyre behaves.
Grooves and sipes: Deep grooves between the tread blocks play a key role in allowing your tyre to shed water, mud and snow. Small slits in the tread blocks know as sipes are designed to deliver extra grip. Grooving and siping patterns are especially important in tyres designed for tough conditions, e.g. winter tyres.
Rib: The solid line running down the centre of the tyre is called the rib. Its job is to provide the tyre with additional reinforcement.