TYRE ATTENTION

Sun (Auckland), Volume 1, Issue 91, 8 July 1927, Page 20 (Supplement)

TYRE ATTENTION

USEFUL INFORMATION WHAT TO DO WITH THEM When buying a car most men make a thorough inspection of the engine and the chassis, but few realise the importance of studying the tyre equipment (writes Albert L. Clough, in the “Weekly Scotsman”). Tyre prices have fallen in recent months, but the cost of the tyres still represents an appreciable portion of the cost of the car. It is possible to economise in tyres without fitting products of an inferior make. Tyres that are slightly too small for the car may be provided. A tyre that carries a load in excess of a certain amount is overloaded, and proves unsatisfactory and uneconomical in several ways. It is frequently punctured and is subject to bruising, which results in fabric breaks, pinched tubes, and deflation. Vulcanising these injuries is expensive, but the annoyance of frequent delays on the road and changes to the spare is at least equally disadvantageous. Moreover, an overworked tyre will give but a relatively short service before it fails utterly, and its cost per mile may prove unreasonably high. The same tyre used upon a lighter car, and thus normally loaded or slightly underloaded, will probably prove highly reliable, require practically no repairs, and run up a very creditable mileage. “SKIMPED” EQUIPMENT

It is of the greatest importance that every car should be equipped with tyres that are of large enough cross section to carry the load imposed upon them without being subjected to abnormally destructive stresses.

Very intensive competition exists among motor-car manufacturers to offer the public “the most car for the least money,” and in this endeavour the utmost economy in equipment must be resorted to. Costs must be pared down to the lowest practicable point and it sometimes happens that the tyre equipment is “skimped,” to the later disadvantage of owners.

In selecting a car the adequacy of the tyres with which it is fitted should be investigated. The weights of all

cars and their standard tyre sizes published in tabular form, and 'veil for the prospective purchaser ascertain whether the car he is c templating buying has as large t v ° n ' as others of the same weight. ° 3res

If suspicion arises that the car unrt contemplation is under-tyred it usuaiT is advantageous. to have it deHvSJ with tyres of a larger size, and to the difference in cost of the two eaui ments; but if this is not done them!?* chaser should at least assure himiif that there is an oversize tyre anr,»L U able to the same rims, which can hi resorted to in case the usual tyre equin! ment is found to be less liberal t?u reliability and low per-mile cost demand TESTING A LEAKING VALVE

The graduated escape of air from - tyre and its premature deflation is a j ways a nuisance, as it entails inordln ately frequent recourse to pumping * Running balloon tyres in an over-soft condition is rapidly destructive to them When one tyre “goes down” faster than the others the most likely Presumption is that its valve leaks. Turn the wheel until its valve stem is at its uppermost position, remove the valve cap and immerse the stem in a tumbler fun J water. If bubbles escape from th« valve stem the valve leaks.

Possibly by screwing in the valve-fa. side or plunger more tightly, with the slotted end of the cap, the leak may be stopped, but if not screw out the plunger, wet its packing and replace it. If this does not prevent leakage r?place the old valve inside with a new one, testing it for tightness. FABRIC BREAK

Occasionally a valve stem has a defective seat and no plunger will fit airtight to it.

In this case have the seat taken out or have a new stem put into the tube Should it happen that the valve tests “tight,” the tube itself leaks and should be removed and tested for air bubbles under water after it has been lightly inflated.

Note how the tube lay in the casing, so that when the leak has been found its position therein can be identified and examined to see if there is an inside fabric break at this point which has pinched the tube, or a nail or other sharp object, just protruding through the casing, that lias made a minute puncture in the tube.

Occasionally a tube is found to leak slowly where the valve stem is inserted in it.