Drivers!
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Tyre Life is Your Responsibility
How the Man at the Wheel can Protect and Lengthen the Life of the Tyre by Following a Few, Simple Rules
WE should all be prepared to agree that the driver is one of the chief controlling influences over the life bfthe tyre's. There is much that he can do for neglect to do), in both actualdriving and in periodical attention as well, which will affect performance.
Bad driving, froth the point of view of the tyre, is of two distinct kinds, and is usually a natural result of differences in temperament. Harsh, brutal misuse is one form of bad driving, and wanton neglect is the other. Apart from the purely mechanical influences which control tyre life there are many for which the driver is almost entirely responsible.
• First and foremost is average speed, with 'which acceleration and braking are closely allied. Obviously, a driver • who travels fast will use his brakes more frequently and much more strenuously than one who travels at a moderate pace. The rate of tyre wear increases in far greater proportion than the increase in speed. A tyre which never travels faster than 30 m.p.h. will give twice the mileage of one driven constantly at 50 m.p.h. Fierce acceleration and braking Will produce considerable " slippage " between the tread and the mad surface.
In other words the tyre tread travels either a greater or lesser distance than the actual ground covered. This difference, in some cases amounting to three or four per cent., is responsible for terrific abrasion, and consequent loss of tread rubber.
A sudden harsh stop, involving, perhaps, 20 yds. of acute abrasion between rubber and tarmacadam, will result in far greater wear than 20-miles of steady travel. The rate of wear is increased more than 2,000 times in that momentary braking effort.
Acceleration has the same effect. The weak link in the transmission syStem is the grip between the tyre and the road surface. Under fierce propulsion stresses, this grip will slip before the inertia of the vehicle is overcome. A fast getaway is, therefore, almost as damaging as a harsh application of the brakes.
Correct loading, too, is a vital factor in the welfare of tyres. A badly distributed load will throw an unequal stress on the tyres. On one side of the vehicle they may be grossly overloaded, whilst on the other they are scarcely working to capacity.
Sometimes, through overloading on the tail of a lorry, the rear tyres are doing all the work, whilst there is hardly any load on the front. Even short distances travelled under such conditions will have a marked effect on the life of the tyres.
Here, again, the remedy often rests with the driver. He can see, not only that his load is distributed properly, but also that it does not exceed the carrying capacity of the tyres, for overloading is the short cut to bursts and rapid tread w ear. Neglect takes several forms, but the most common of all is that of unsys, ternatie inflation. Tyres Should he checked at least once a week. 'A small percentage of loss of air pressure will result,in a big percentage of lost mileage.
One of the most common offences of some drivers is the tendency to run on a tyre which is known to he punctured. They would prefer to have the leaking tyre blown up from day to day, rather than get down to it properly and change the wheel. Little do they realize the damage that is done by running a cover in such a condition.
In the same way, many drivers, having sustained a puncture on a vehicle fitted with twin rears, will finish their journey without changing the wheel, hoping that the one remaining sound tyre will survive the ordeal. The evil effect of this policy is twofold. The flat tyre, lacking the air pressure which maintains its normal shape, will thrash about in such a violent manner that the tread rubber will be removed in large scoops. A new tyre can, in this manner, be worn out in a few miles. Although there is no weight actually resting on it, the ground abrasion is terrific, due to the lack of air support.
Meanwhile, the other tyre, the sound one, is carrying all the weight that falls to that side of the vehicle. It is doing double work, It cannot stand up to this for long and very soon two tyres are ruined because the driver neglected to give a little attention to the initial puncture.
Damage from Trapped Stones Another form of neglect that is responsible for much damage is the failure to remove trapped stones from between twin tyres. At every revolution of the wheel the stone is gouged into the tyre wall, and before long several plies of cord are chafed through.
In the same way, flints and fragments of metal which enter tread cuts should be systematically removed, for if they be left they will gradually work their way through to the tube.
Two more forms of damage for which the driver is responsitie are attributable to carelessness and errors of judgment. They are concussion bursts and excessive kerbing. The latter is not usually very serious, and is much more common on passenger-carrying vehicles than on those transporting goods.
Constant contact with the kerbstone. WISen pulling into the side of the road, will cause abrasion on the wall of the, tyre, which may eventually wear throagh several plies of cord.
A more serious aspect of a blow against the kerb is that it frequently results in an alteration in front-wheel alignment, which, in turn, will cause rapid tread wear on one or both of the front tyres. This is a condition which is easily detected by a sharp feather edge on the tread blocks of the tyres. Immediate correction is necessary or big mileage losses will follow.
Concussion damage is really serious. A tyre, almost new, is often discarded as a result of a burst caused by violent impact with some obstruction, such as a brickbat, kerb, steel rail, etc. It is easily realized how the cords of the tyre carcase, stretched tight by the internal air pressure, will quickly snap when subjected to any sudden shack.