Vipal Rubber brings you valuable technical information to help you get the most from your tyres. This month – the parts of a tyre.
The tyre is one of the most essential parts of modern commercial vehicles. Correctly inflated tyres support the weight of the load and are the vehicle’s interface with the ground.
The tyre transfers the engine power to the ground in the form of traction. It is also responsible for the grip contact when braking and the vehicle’s stability. That is why it is essential to understand the tyre’s structure and the features of each type, model and their applications.
Again, it is important that tyre pressures are maintained and checked regularly. This maintenance will assist you in achieving the maximum safety and tyre mileage on your vehicle.
The tyre’s main parts are:
(1) Tread: The part of the tyre that has contact with the ground.
(2) Tread voids: The pattern embedded into the tread surface, longitudinally and/or transversally.
(3) Shoulders: The part of the tyre between the tread and the sidewalls.
(4) Protection belt: The top protection belt is part of the tyre structure that aims to protect the main belt/ply package.
(5) Steel radial belt plies: External part of the radial tyre’s tyre structure, which aims to stabilise the tyre.
(6) Inner liner: The whole inner surface, consisting of rubber components, responsible for the airtight protection of the tyre.
(7) Body ply: Inner part of the tyre structure where the radial cords extend from bead to bead.
(8) Sidewalls: The flexible part of the tyre located between the crown of the tyre and the beads.
(9) Guide rib or G-G ring: A raised line near the bead area to visually show the accurate centralisation of the tyre in the rim when the tyre is fitted.
(10) Beads: Parts of the tyre that are in contact with the rim, assuring its fixing.
(11) Bead bundle: Inner steel cords of the bead.
(12) Casing: Complete tyre structure formed by plies/belts, beads and tread rubber area.
(13) Cords: Metallic radial or fabric twisted cord plies shape the casing and provide the belt/ ply structure.
(14) Tread wear indicator (T.W.I.): Raised bars placed on the bottom of the tread grooves visually indicate when the tyre is at its maximum wear limit.
