Tires

TiresPerform two basic functions:

•Act as a soft Cushion between the road and the metal wheel.

•Provide adequate traction (friction) with the road surface.

TiresParts

•Beads two rings that are made of steel wire and encased in rubber. They hold tire side walls snugly against the rim.

•Body Plies rubberized fabric and cords wrapped around beads. Form carcass or body of the tire.

•Tread outer surface of the tire that contacts the road.

TiresParts

•Sidewall outer part of the tire that extends from the bead to the tread. Marking on the sidewall provides the information about the tire.

•Liner thin layer of rubber that is bonded to the inside of the plies. It provides a leak proof membrane for tubeless tires.

•Belts used to strengthen the body plies and and stiffen the tread. They lay between the tread and plies.

Tires

Tire ConstructionBias Ply Tires

•The plies run at an angle from bead to bead.

•One of the oldest design.

•Does not use any belts.

•Allows body of the tire to flex easily.

•Improved cushioning, hence smooth ride on rough roads.

•Weakness of Bias-plies is that it reduces traction at high speeds and increase rolling resistance.

Tire ConstructionBelted Bias Tire

•Bias ply tires with belts added to increase tread stiffness.

•Belts and plies run at different angles.

•Belts do not run around the sidewalls, they lay under the tread area only.

•Provides smooth ride and good traction.

•Offers some reduction in rolling resistance over a bias ply tire.

Tire ConstructionRadial Ply Tire

•Plies running straight across from bead to bead, with stabilizer belts directly beneath the tread.

•Has a very flexible sidewall and a stiff tread, giving it a very stable footprint.

•Disadvantage is that it may produce a harder, or harsher, ride at low speeds.

Tire Construction

Tire Markings

Tires

M — 81 N — 87 P — 93

Q — 100 R — 106 S — 112 T — 118 H — 130 V — 149 W — 168 Y — 186

Load Index

Pounds

Kilograms

Load Index

Pounds

Kilograms

71 761 345 91 1356 615

72 783 355 92 1389 630

73 805 365 93 1433 650

74 827 375 94 1477 670

75 853 387 95 1521 690

76 882 400 96 1565 710

77 908 412 97 1609 730

78 937 425 98 1653 750

79 963 437 99 1709 775

80 992 450 100 1764 800

81 1019 462 101 1819 825

82 1047 475 102 1874 850

83 1074 487 103 1929 875

Speed Rating

Tires

Expiry Date•Tires have a shelf life of six years

•They are known to explode (tread comes apart)

Tires

Tires problems

Tires problems

Tires problemsFeathering

•Improper alignment (TOE).•Worn or damaged steering or suspension parts.•Hard cornering.

Cupping •Worn or damaged steering or suspension parts.•Improper balancing.

One Edge•Improper alignment (CAMBER).•Worn or damaged steering or suspension parts.

Tire Rotation

TiresTread Wear Markings

Tires

CREDITSGoogle Images