Factors influencing tyre life:
We hardly stand a chance to sustain the best health of a high quality tyre, when the product is not inflated to an optimum pressure as recommended for its excellent health and performance. Here the recommended pressure is referred to as the one that commensurate with the load carried. Top class tyre performance can only be achieved when the tyres are inflated to the recommended pressure based on load exerted on each tyre.
“Under” or “Over” inflation can have an impact on tyre life, vehicle safety and handling. There are two main factors directly related to the weight distribution of the vehicle. While the first one is related to contact patch the other has its connection with tyre wear. These two factors can primarily lead to heat buildup/tyre temperature, premature tyre replacement, tyre loss, increased fuel consumption and rolling resistance.
It is important to remember that the total weight (GVW) carried may not exceed the registered laden weight (RLW) or vehicle passing weight, but one side of the truck or one axle may be severely overloaded due to improper distribution of the load in the pay load platform or loading area.
Improper load distribution overloads the tyre(s). This condition combines with high speed , long hauls and load transfers resulting in tyres wearing fast and premature removal of tyres
Under Inflation” is more common than Over inflation. Tyre users are not always conscious about maintaining or matching tyre pressure to the loads carried.
In pneumatic tyre the “Air carries the load”. The best tyre performance and lower tyre CPKM are obtained by maintaining correct tyre inflation pressure.
Load and loading techniques
With even one trip, the tyres of a truck improperly distributed with goods can be subjected to irrecoverable damage.
A wheel which is not properly balanced may setup vibrations which can affect steering control. Wheels, tyres and tubes are usually checked for balance before leaving factory.
Properly balanced tyres are important for driving comfort and long tyre life.
This balance is achieved by positioning weights on the wheel to counterbalance heavy spots on the tyre wheel assembly.
Tyres should be balanced when they are mounted on the wheels for the first time or when they are removed for repair or periodically as per vehicle manufacturer’s recommendations.
- A vehicle is said to be properly aligned when all the steering and suspension components are set as per the vehicle manufacturer and when the tyre wheel assembly are running straight and true.
- It is recommended to get the vehicle alignment checked and corrected as per vehicle owner’s manual as soon as tyres start wearing unevenly or ride handling problems(vibrations, pulling to one side etc).
- Proper alignment is necessary for perfect vehicle control, uniform and even tyre wear and safety.
- Excessive high speeds results in increased tyre running temperature. As the rubber gets heated up its modulus (stiffness) gets reduced.
Rubber being a good non conductor of heat the residual heat is retained causing increased tyre wear and separation of components.
It is preferred to rotate tyres as per vehicle manufacturers recommendation or in case of any uneven tyre wear noticed.
- Rotation of tyre in a vehicle is recommended for a uniform tyre tread wear on all wheel position to achieve optimum tyre life.
- It is suggested to check wheel alignment, wheel balance and suspension before the tyres are rotated. Rotation patterns /pictures to be incorporated.
Tyre/vehicle operating conditions significantly affecting tyre life with regards to structural durability and new tyre life:
- Paved road
Rough/abrasive road surface
Broken up roads
Unmade country roads
Hilly windings roads
Climatic and weather conditions in our country vary widely from region to region. Dry and extremely hot during summer, extreme cold during winter and rains during monsoon.
The variation in climatic conditions influences tyre life in terms of mileage and structural durability.
For optimum tyre life it is best to focus on careful diving habits. Evading unavoidable damage and severe road accidents can enhance longevity of tyres. Some of the habits which cause serious damages to tyre and road accidents are:
Speeding over pot holes, stone etc.
Riding over road divider and other obstacles
Quick starts and sudden stops
Hitting the road, curbs, objects etc.
Sharp turns at high speeds
Running on improperly inflated tyres
Do's & Dont's
- Tyre Pressure checks including the spare tyre must be done regularly at least once in two weeks.
- Tyre pressure should be checked when tyres are cold.
- Tyre pressure should be checked using an accurate pressure gauge.
- Tyre pressure should always be maintained as per the vehicle manufacturers recommendations, mentioned at information placard, at door, owner’s manual.
- Under inflation and over inflation will cause rapid tread wear and premature tyre failures.
Getting the right tyre
Optimal and safe operation of a vehicle is highly dependent on the appropriate selection of tyres. A few critical factors to consider before choosing the perfect tyre are discussed below:
- The type of load and its weight (Load Index/PR)
- The vehicle type and its usage (passenger or goods)
- Tyre type/rim combination (size of tyre and rim typer)
- Sustained operations and speed (Speed Symbol)
- Tyre design requirements based on application
- Vehicle operating conditions (Type of terrain/roads)
Tyre mounting and dismounting
- The wheel should undergo proper cleansing in order to eradicate contamination
- Rim size should fit around a tyre most appropriately
- Lubricating tyre beads with a globally certified tyre lubricant
- Ensure that the tyre is mounted on a wheel free from damage, deformity and bent
- Tubeless tyres should be essentially fitted on air-tight rims
- To maintain safety it is essential to fit a tyre with a new tube to avoid hazards
- While inflating the tyres on the rim ensure that tyre beads sit properly on the rim seat.
- Ensure that the vehicle is not subjected to tyre bursts due to exposed piles and damage
- Before removing the tyre ensure that you deflate the same
Warning to ensure tyre safety
Tread Wear Indicator (TWI)
- Never mount or use damaged tyres/ rims.
- Tyre mounting / demounting and changing can be dangerous and should be done by trained personnel using proper tools and procedure.
- Never use inflammable substance into a tyre.
- Explosion of tyre rim assembly due to improper mounting, mis-application, improper inflation or overloading leading to serious injuries or death.
- Never use tyre worn beyond TWI
- Avoid fast start, stops and turns.
- Observe posted speed limits
- Do not run over curbs and hit the tyre against side railings, dividers and curbs.
- Avoid potholes and objects on the roads.
- Do not spin the wheels.
- Do not overload tyres.
- It is dangerous to neglect tyre damages.
Visual inspection of tyres
Since Pneumatic tyres are subjected to the following conditions they are considered unsafe:
- Tyres having incipient failures by local deformation, bulging, swelling etc.
- Tyre body fabric/belts/plies exposed by wear, by injury, road hazards, damage, abrasions or scoring etc.
- Pneumatic tyre which has been patched or repaired improperly or use of gaiter other than proper repair and vulcanization.
- Broken cord or run flat due to puncture, damage in bead area, damaged Inner liner of tubeless tyre
- Tyre worn beyond tread wear indicator, having signs of severe uneven, mis-alignment, patchy wear.
LOAD SPEED INDEX
Load Index: This is referred to a numerical code associated with maximum load a tyre can bear at a speed indicated by the speed symbol under specific service condition.
Speed symbol: The symbol is an alphabet indicating the maximum speed limit for a tyre bearing load relative to its load index.