In order to ensure longer functional life for your tyres, it is important to carefully maintain them. Experts advice that there are some factors that can be taken into consideration to sustain the quality of tyres for longer duration.
Factors Influencing Tyre Life
- Inflation Pressure
- Dual Spacing, Matching & Tyre Rotation
- Mechanical Conditions
- Proper Loading
- Operating Conditions
- Driving Habits
Technical Terms on Alignment Angles
- TOE-IN: It is when both front wheels are closer to each other when viewed from the front. Excessive toe-in wears the outside of the tyre.
- TOE-OUT: It is when both front wheels are far away from each other when viewed from the front. Excessive toe-out wears the inside of the tyre.
- Negative Camber: It is when both front wheels are closer to each other when viewed from the top.
- Positive Camber: It is when both front wheels are far away from each other when viewed from the top.
- Positive Caster: Caster angle is the backward tilt of the axle, or inclination of the king pin at the top, which makes the wheel draw and automatically adjust, depending on the direction of track.
- Negative Caster: Incorrect caster causes the wheel to be pulled to one side resulting in severe and irregular tread wear.
- King Pin Inclination: It is the angle of the steering axis, relative to the road surface, as illustrated. It stabilizes the wheel at the neutral position and assists in a self-centering action to be generated. Loose king pin results in fast and uneven tread wear.
- Steering Set Back: It is the “set back” of one wheel when compared with the other on the axle. It means one wheel is slightly behind the other, instead of being in line with it.
- Thrust Angle: It is the angle between the geometric centerline & the thrust line due to miss-alignment of the axle as shown in the figure.
Dos n Don’ts
- For tubeless tyres, it is recommended to use new tyre with new valve
- New tyre with new tubes and flaps should be used for tube type tyres
- Radial tyres should not be mixed with bias tyres in dual assembly
- Radial tyres and bias tyres must not be mixed on the same axle. Always ensure that one side is radial tyre and other side is bias tyres.
- Different tyre sizes or tyre constructions should not be placed on the same axle
Dos n Don’ts of Wheels and Rims
- Proper tyre size and construction should be selected to match the manufacturer’s rim or wheel rating and size
- Rim diameter should be properly checked to be sure that it matches exactly the rim diameter specification on the tyre sidewall
- Damaged rim should never be mounted or used. It is suggested to always inspect and clean the rim before fitment
- Reworked, welded, de-shaped or brazed rim should not be used
- It is essential to ensure that rim components are properly coordinated
- Scraps broken and welded rings and locks
- An unidentified rim/wheel component should not be used
- Only approved tyre rims should be used when mounting
- Tyre’s inside surface, tube, flap as well as the inside surface of the rim or wheel should be clean, dry and free from rusts. This should always be ensured before mounting a tyre on a rim or a wheel.
Dos n Don’ts of Inflation Pressure
- As most tyre damage is due to incorrect inflation pressure, it is vital to ensure that truck and bus tyres are inflated according to the load they carry.
- Tyre pressure should be checked using a reliable pressure gauge.
- If tyre looses air frequently, make sure to check tyres for punctures. Do not overlook tyre. It is suggested not to fill air and drive to destination.
- Tyre pressure checks should always be made on cold tyres. Do not check and adjust the inflation pressure when the tyre is warm.
- The sealing valve cap acts as a supplementary air seal and should always be secured. Valve caps should be used to keep the valves clear of debris as well as to help guard against inflation pressure loss.
- Vehicle with under-inflated or flat tyres should not be used for transportation
- Incorrect inflation pressure causes irregular tread wear, order to minimise irregular wearing. As per load carried, tyres should be inflated keeping in mind the recommended cold pressures.
- Rotate your tires according to the vehicle manufacturer’s recommendations for maximum mileage (consult your vehicle owner’s manual)
Driving on tires with improper inflation pressure is dangerous. Below are the reasons:
- Under-inflation causes excessive tire heat build-up and internal structural damage.
- Over-inflation makes it more likely for tires to be cut, punctured or broken by sudden impact.
- An accurate pressure gauge should be used or an appropriately designed pressure filling stations for safety.
- Inflation pressure should be checked when the tires are ‘cold.’ Tires are considered ‘cold’ when the vehicle has been parked for three to ten hours or more, or if the vehicle has been driven less than a mile.
- Tires should be inspected for uneven wear. Wear on one side of the tread or flat spots in the tread may indicate a problem with the tire or vehicle.
- Vehicle suspension parts, tyres, rims or wheels should be periodically checked for bents, cracks or dents.
- Wheels nuts must be present and securing rims/tyre assembly on the vehicle.
- Leaking Oils/greese from wheels hubs should be immediately taken care of as it can flow from hubs to wheels then to tyres.
- As per the type of vehicle usages, periodical plans should be fixed for tyre rotation and vehicle alignment.
- Perform rotations and alignment at half of the vehicle manufacturer’s recommendations for vehicle moving on bad terrains.
- Tyres should not be stored in direct sunlight or near heat sources. It is suggested to keep tyres away from motors and generators.
- It is also essential to keep tyres away from oils and chemicals.
- Un-mounted tyres/ casings should be stored indoor in a dry location as well as away from moisture and heat.
- Tyres should be removed for recapping/retreading at Tread Wear Indicators (TWI). Tyres should not run after minimum tread wear is reached.