adminA vehicle with all its weight and power of perambulation was given an equally capable component to afford it control and stability. A tyre is a component that revolutionised motoring and transportation in general, thanks to the great inventor John Boyd Dunlop.
Now vehicles are capable of carrying hundreds of thousands of tonnes and can move at supersonic speeds driving on tyres albeit specially designed to match these demands.
The same enormous vehicular capabilities have also become a curse on humankind as the vehicle has replaced dangerous animals and killer diseases in claiming human lives.
Since vehicles are capable of ferrying huge numbers of people, a crash can account for a big number of human lives. Furthermore, with the high speeds which vehicles do, a crash can cause great damage and can easily be fatal.
It is unfortunate that tyres, a component responsible for carrying a vehicle and its occupants, are usually ignored by drivers. This season usually witnesses a lot of accidents, some of which point to tyre negligence.
In this instalment, which is one of a series that we are going to publish over a month, we are going to discuss good tyre care tips, encouraging our drivers to care for their tyres and hopefully reduce road carnage this coming holiday.
Tyre Selection
The first action in good tyre care has to do with proper tyre selection for one’s vehicle.
Wrong tyre selection often leads to premature tyre failure as the tyre is predestined to fail in a wrong application. Vehicles are manufactured for various purposes ranging from load-carrying, load-pulling and for light work, in road conditions that also vary from well paved tarred roads to dirty harsh off-road.
Models also differ in their gross weight and specifications, necessitating variations in tyre size applications.
Tyres that are fitted on passenger vehicles have a different construction to those fitted on light trucks. Passenger vehicles, by their nature, do not carry heavy loads and therefore the tyres for these vehicles are not reinforced.
However, they are made to match high speed capabilities of these small vehicles.
Passenger car tyre sizes range from 155R12 to 275/45R20 with some latest models even coming on 22,5-inch sizes. It should be borne in mind that light truck vehicles also have the same range of tyre sizes although, as noted earlier, with a different construction. It is common to hear a customer asking for a 14-inch tyre without a clue what the other dimensions are.
They are usually worried about the rim diameter only, assuming that for as long as the tyre fits on a rim it should do the work. Practically this is not possible as there are various sizes with a 14-inch diameter, from 165R14 to 205R14.
The overall diameters of this range of tyres are different, implying that the 165R14 is much smaller than a 205R14. We therefore urge motorists to be well versed with the full description of their tyre sizes. Rim diameter may be the same but tyre diameter may differ.
While light truck tyres are capable of carrying heavy loads, they may not be able to do high speeds associated with high performance passenger cars. When selecting a tyre for a passenger car, one must not only be wary of the actual size dimensions. One needs to be cautious of the speed capabilities of the tyre too.
Tyres generate more heat at high speeds because of the excessive flexing of the sidewall, the friction of the tyre components and the heat from the drums. High performance tyres are made to be able to dissipate heat faster, run cooler and therefore eliminating the risk of disintegration. It is important to note that there is a limit to the speed a tyre can achieve.
Tyre manufacturers put speed symbols indicating the maximum speed a tyre can make, all things — pressure, load and road conditions — being equal. A chart has been attached at the bottom of this article to give you some idea of the corresponding speeds for each speed symbol.
Wrong size application can result in mechanical damage to the vehicle’s diff. If one wants to change the original size and move to a wider tyre, one should always consult a tyre inter changeability chart. When selecting a tyre size for a light truck, one must be aware of the exact size, load carrying capacity and the application.
Proper Tyre Fitment
Once a tyre has been selected it has to be fitted on to the rim before it can be used on a vehicle.
Tyre fitment, simple as it seems, must be done properly and with extreme caution to ensure maximum tyre life.
In this regard I recommend that motorists use professionally set up workshops with the right equipment and trained staff for a quality service and refrain from the cheap roadside hammer and chisel fitting places.
It may appear like these roadside shops provide convenience, but a closer scrutiny will reveal that they cause more harm than good.
Their working area is dirty and the grit from the loose sand can be trapped around the bead causing pressure leaks. The other day a commuter operator came to our shop complaining about pressure loss from his tyres.
Upon investigation we noted that the pressure was coming out through the bead and we stripped the tyre from the rim. Further investigations revealed that paper was used to sit the bead onto the rim since the fitter did not have proper fitting equipment. In most cases these fitters use their hammer and chisel to force the bead to sit causing damage to the tyre.
a) Proper tyre and rim selection
The reasons for proper tyre selection have already been discussed above, so we are going to focus on rim selection. Tyres are not just fitted to any rim with the corresponding diameter.
There is the rim width what is technically called the J of a rim, to consider as well. The J aspect of a rim determines its width. It then follows that a narrow tyre must be fitted to a narrow rim and a wide tyre to a wide rim.
Online Reporter