Bead – The part of the tyre, which is so shaped as to fit the rim and hold the tyre on to it. It has cores made of several strands of essentially inextensible steel wire with the end of the plies wrapped around the cores for anchorage.
Sidewall- The part of the tyre between the bead and the tread, which flexes in service.
Tread – This is the part of the tyre which comes in contact with the ground and through which the driving, braking and cornering forces are transmitted. It is made of a special rubber compound to give good wearing properties and in conjunction with the tread pattern to transmit these forces.
Ply – A layer of rubber coated fabric cords.
Carcass – The rubber-bonded cord structure of a tyre integral with the bead which provides the requisite strength to carry the load.
Breaker (Diagonal)- Intermediate rubberised fabric layers/plies between the carcass and the tread which helps bonding as well as protects the casing from road shocks.
Belt (Radial) – Layers of rubberised material underneath the tread with cords laid substantially in the direction of the tread centre-line that restricts the carcass in the circumferential direction and stiffens the tread area.
Carcass ply cords run at 90 degrees to circumferential axis.
Carcass stabilized by steel belts.
Carcass ply cords run Carcass ply cords run at an angle with respect to 90 degrees to circumferential axis of the circumferential axis.
Advantages of Radial tyres :
Longer tyre life resulting from lesser tread squirming & shuffling.
Improved fuel efficiency due to Reduced rolling resistance.
Better high speed performance: Better dimensional & directional stability due to reduced edgewise bending.
Better Vehicle handling due to:
Minimum distortion in foot print area
Higher flexibility of sidewalls
Reduced side slip
Automotive Tyre Manufacturer’s Association
PHD House, 4th Floor, Siri Institutional Area,
Opp. Asian Games Village, New Delhi – 110 016