1. TYRE BASICS

What is the difference between Radial and Bias tyres?

A Bias tyre  has multiple layers of body plies that criss-cross each other, while a Radial ply tyre has only one radial body ply.

What is the difference between tube type and tubeless tyres?

A tubeless tyre is basically a tyre that has a thin layer of air and moisture resistant rubber used on the inside of the tubeless tyre from bead to bead to obtain an internal sealing of the casing. The tubeless tyre retains the inflated pressure between it and the rim. A tubetype tyre uses the tube to retain the inflation pressure.

What are low profile tyres?

The profile or aspect ratio of a tyre is the ratio of the tyre width to the height from the rim to the tread on one side (section height). If the ratio or profile is low then the tyre will have a much shorter sidewall compared to the width. For instance an a 65 series tyre has a lower profile compared to a 75 series tyre

What do the writings on the sidewalls mean?

The sidewalls carry information describing the tyre size and the tyre abilities. For example:
185/70R14 90S means:

185 à The tyre width in millimeters.

/70  à The aspect ration or profile - The size of the sidewall as a percentage of the width

R     à This indicates that the tyre is of radial construction. Bias tyres usually have a dash “-“ instead of the R.

14   à This is the rim diameter in inches.

• à This is the load index, which is a number representing the maximum load (eg 90 index  = 600kg)you can carry at the speed indicated (speed symbol).

S     à This is the Speed symbol, which represents the maximum speed capability of the tyre at the maximum load indicated (load index). Common speed symbols are S, T, H, V for passenger radials and G, J, K, L, M for TBR. For example S speed symbol indicates 180 km/h

Some tyres have imperial measurements (all in inches) but the numbers signify the same as above. For example
7.50-16  12PR means:

• à The section width of the tyre in inches

“-“à This signifies that this is a bias tyre.

• à The Rim diameter in inches

12PR à This indicates the load carrying capacity at the corresponding inflation pressure. It is based on the initial tyre building system where the layers were made of cotton fabric. With stronger modern materials this no longer means the number of layers of fabric. The ply rating allows comparison between same size only – not tyres of different sizes. A higher ply rating means a higher load capacity and a higher pressure.

2. TYRE CARE

What inflation pressure do I use?

The recommended inflation pressure is written on a sticker placed on the driver’s door pillar (door way), the vehicle dash-board or the vehicle manual and as recommended by the tyre manufacturer. Over or under inflation will not only generate irregular tread wear patterns, but can also lead to premature tyre failure.

How do we perform repairs on tubeless tyres?

Tubeless repairs to the tread area need to seal the hole completely leaving no room for water penetration to the belts. This is why plug type repairs are required.

What are the different tread patterns for?

The tread patterns are designed to give the different performance characteristics of the tyre in terms of handling on dry and wet roads, traction for braking and acceleration, mud, sand and snow ejection ability, cornering performance and fuel economy.

Generally most passenger tyres will have a mixture of tread patterns depending upon the function and terrain for which the tyre is designed.

What is tyre rotation?

Tyre rotation is the activity where the tyre positions are exchanged on the vehicle to achieve increased tyre life. It is recommended that your perform tyre rotation every 5,000km and at a shorter interval when the tyres are new.

How is proper Rotation done?

Why do I need wheel alignment?

Wheel alignment is defined as the angle of the wheels of a vehicle, and/or suspension and steering components, relative to:
 Each other, the centerline of the vehicle and the direction of travel. For front wheel alignment, the 3 angles of alignment are : Caster, Camber and Toe. Depending on road surface conditions it is recommended that this is done at least at every vehicle service.

Why do I need wheel balancing?

Tyre noise is transmitted into the car in motion in two ways: by passing through the air and through the wheel and suspension. These vehicle vibrations or ride disturbances can be due to incorrect dynamic balance or static balance among other factors. Wheel balancing is the act of providing a counter weights for the imbalance on a tyre/rim assembly to prevent tyre vibrations and ride disturbance.

Why you should avoid worn out tyres

• They easily slip on wet roads
• They easily get punctured
• They easily get cuts or bursts

When are your tyres worn?

• Tyres are worn out when the remaining tread depth reaches the Tread Wear Indicator.
• This corresponds to:
  • 1.6 mm for passenger cars
  • 2.4 mm for light trucks and vans
  • 3.2 mm for trucks & buses