User Guide for Wheels and Tyres.
Wheels and tyres have always been an important part in automobiles as they are the point of contact between the vehicle and the surface. They are also responsible for hauling the vehicle load on them.Though, they form an important part in modern automobiles, maintaining them is something that is not paid much attention unless they go through excessive wear and tear and need replacement. We investigate more on this and find out the different parameters behind tyre selection as well as how to maintain wheels and tyres.
Wheels
Wheels are made of either pressed steel discs or could be of Aluminum and/or Magnesium alloy. Alloy wheels are lighter in weight compared to steel wheels. The center of wheels is tapered with holes to enable fitment of bolts. It could be pentagonal or Hexagonal depending upon the preference of different manufacturers.
Wheel dimensions consist of width and diameter. Width refers to the measurement from one flange to other on top of the rim. Diameter refers to outer circumference to bottom circumference of wheel.
Tyres
The main purpose of tyres is to provide road contact and hence traction. The weight of the vehicle is supported by the air filled in tyres. Tyres could be of Tubed or Tubeless type. Modern cars come with tubeless tyre as OEM parts.
Tubed tyres consist of a separate tube inserted in the tyres to hold air. Tubed tyres have advantage of lower cost and cost of repair and replacement of tube would also be comparatively cheaper than tubeless tyres.
Tubeless tyres don’t have separate tube and the tyre is mounted on special rim that retains air between the rim and the tyre casing when the tyre is inflated. Tyres also have soft inner linings that keep air from leaking between rim and tyre. In some tyres, self sealing rubber compound is put inside the tyres. It can seal up the minor hole after removal of object nails etc.
Tyre Rating
Tires are rated by their profile ratio or aspect ratio, size and load range. A tyre profile is the relation of cross section height compared to its width.
For example: If Tire rating is mentioned as 195/75 R14. 195 Refers to width in mm, 75 refers to height to width ratio. R refers to radial construction.R14 refers to rim diameter of 14 inch.
Also on side walls of tire there would be markings of maximum load, temperature, maximum inflation and thread plies etc. The maximum load refers to the maximum load the tyre can carry at recommended tyre pressure.
Tyre care.
Some of the tips for getting best performance from tyres are listed below
1. Regularly inspect improper inflation and uneven wear of tyres. Uneven wear could indicate need of checking wheel alignment and balancing.
2. Check for cuts, stone bruises, abrasions, blisters, or any objects that could be imbedded in the tread.
3. Whenever the vehicle is driven in extreme temperature conditions, rough road conditions, it’s recommended to check the tyres when vehicle is stopped.
4. Inflation of tyres is to be done as recommended .Generally Tyre pressure is indicated on the plate put at door pillars. A higher tyre pressure (over inflation) would lead to excessive bulge at center portion and under inflation would lead to excessive wear at edges. A proper inflation would result in maximum life of the tyre.
5. Tyre Rotation
To ensure uniform tyre rotation automobile manufacturer recommends the tyres to be rotated (changing the location of tyre).It could be done in any of the method as prescribed in owner’s manual of that particular make and model.
6. Air filling can be done with normal air or nitrogen air as convenient. Advantage of nitrogen air is that its lighter than normal air and can also withstand higher variation in temperature of tire and hence reduce effect on overheat developed during long and continuous driving.
7. Wheel and tyres cleaning
Wheels and tyres can be washed with soap and water. Its best to wash it after taking it out from vehicle However considering the practical difficulty in doing so, it is recommendable to wash as it is in fixed condition.
8. Wheel balancing
For proper rolling of wheels it is essential to keep the wheel balanced i.e. equal weight distribution of the wheel in overall circumference. For this in modern times computerized wheel balancing machine is available. The wheel is mounted on the balancing machine and switched on by setting the console to either static or dynamic balancing as required.The assembly gets rotated until the heavy spot falls to bottom. Weights are added to the positions indicated and repeated to ensure equal balancing.
9. Wheel alignment
The improper wheel alignment could lead to excessive tyre wear, pulling of tyre to one side etc. Wheel alignment and balancing could be done once in every 5000KM or whenever required.
10. Emergency due to Tyre failure
Tyre puncture is a common phenomenon when vehicle is driven on rough road conditions. Generally vehicle would be at slow speeds while moving on an uneven road conditions and hence it won’t be a problem for safe stopping of vehicle.
The major problem is during high speed driving on highways. Many times the tyres burst due to excessive heating. The tyre gets heated up due to prolonged high speed driving, the hot surface of the road due to summer heat etc would add to the combined effect resulting in bursting of tyres due to which the driver would lose control and it can result in a fatal crash.
Some of the precautions that could be taken include, ensuring optimum tyre pressure, giving brief halt after travelling a long distance such as 100kms or more especially during summer conditions during which the heat of road does have major effect.
Avoiding overloading the vehicle with too many passengers more than what the manufacturer officially recommends to be carried in that particular model.
11. Fitting higher rating Wheel and Tyres
It is always recommended to fit the wheels and tyres as recommended in manufacturer specification sheet.
For Example: In Maruti Suzuki Swift Vxi / VDi variants, the Tyre size is 165/80 R14 and in ZXi/ZDi its 185/65 R15. A much higher rating Wheels and tyres won’t be recommendable at all. An incorrect size wheel could result in reduced wheel bearing life, improper clearance between wheel and fenders etc, it could also affect working of Anti Lock Brake system. The prescribed tyre rating is mentioned in specifications of all vehicles.
Buying Wheels and Tyres
The cost of a set of 4 tubed tyres is around Rs.12000 and that of tubeless tyres is around Rs. 15000. Similarly the cost of Steel wheels is at around Rs. 3000 and above and that of Alloy wheels is more than Rs. 7000 per wheel.
Retreaded Tyres
Retreaded Tyres is the name given to the process of putting new caps/Buttons for the worn out tyres with help of special machines. Generally, a retreaded tyre can be used for approximately 20000Km.Retreaded tyres are generally used by trucks where cost of replacement of tyres is higher. Though it could be used as a temporary solution, it should be replaced at earliest for best of safety and comfortable usage of the vehicle.
Conclusion
In the article main focus is on brief details of wheels and tires and maintenance of the same. Practical aspect of wheel and tires such as tyre care, precautionary measures etc are covered. We welcome viewers to share their views and tips for long term usage of wheels and tyres.
