TYRE SERVICE

Hawera Star, Volume LI, 28 May 1932, Page 12

TYRE SERVICE

LOSS THROUGH NEGLECT. POINTS IN SYSTEMATIC INSPECTION. Every clay thousands of pounds are thrown away by motorists, and a further huge sum is added to their running costs, through neglect of their tyres. A motor vehicle only functions in proportion to the time, care, and inspection given to it ; but how many motorists include tyre inspection under this heading? It is dangerous to run an engine short of oil, but how many realise it is equally dangerous to run their tyres short of air? The tyre manufacturers make a tyre suitable for every vehicle at present being manufactured, and issue, in punted form, information showing the conect load any tyre should carry, and the right air pressure necessary to produce maximum riding comfort and minimum fatigue in steering. Eeneath the rubber tread on a tyre is a carcase of cotton, built up to carry a definite load. The side walls of this carcase are so constructed as to ilex without fracturing the cotton. The tyre pressure recommended for any vehicle is such that a motorist can take advantage of this flexing without causing damage to the tyres, but should this pressure be maintained at a higher or lower level than that recommended, the motorist lays himself open to serious trouble at a later date, the interval of time being controlled by a degree of over or under-inflation/ In an under-inflated tyre the flexing of the ? 'd® wall sets up friction, which causes neat. Rubber is a bad conductor of heat and cotton loses its flexing qualities with increased temperature. The Jesuit is that either the cotton cords will fracture or the rubber will .separate from the cotton, thus weakening the sidewalls of the tyre, possibly causnig complete collapse at a verv earlv stage in its life.

An over-inflated tyre compels the | tiead to assume an incorrect contour which does not allow the full tread l 'vicltli of the tyre to com'e into contact with the road surface, so the tvre load is carried by only a portion' of the actual tread. That portion is overloaded, and in consequence generates excessive beat. Immediately underneath the tread is a section known as “cushion,” in other words a layer of lubber around its circumference which is softer than the outside tread. This acts as a shock absorber. Should the tyre be over-inflated, the shock will be absorbed by a small percentage of that cushion, and the benefits which should be obtained are not only eliminated, but the shock and heat are transmit! c to the carcase of the tyre, which deteriorates rapidly. Pressure, however, whilst a very important factor, is not everything to he considered when caring for tyres. Few motorists appear to appreciate that it is possible to wear the tread completely off any tyre in an extraordinarily low mileage should the wheels of the vehicle be running out of alignment. You cannot see in many cases when looking at a

vehicle whether or not the wheels are running m line, and it is necessary to have them checked by a service agent to obtain the maximum life built into them by the manufacturer. There is also a further condition which requires consideration, that is, cuts in tyres. Should a tyre receive a cut which penetrates the tread rubber and exposes the carcase, this cut or hole forms a passage for all foreign matter, including water, into the carcase. The greatest enemy of all is water. In running on wet roads the injury becomes filled with water and the cotton in the carcase soaks up some of this water like blotting paper. This eventually causes the wet cotton to separate from the rubber and soon a section of the tyre has no resistance to tlie internal air pressure beyond the rubber forming the tread or sidewall. This often results in a blister, jnici eventually causes a burst, which ruins both tyre and tube.

A little time spent on inspecting the tyres will be amply repaid by the fact that it will be possible to obtain ma.., mum “life” from them. The following are the major points which, when checked, will go a long way towards achieving this end: 1. —fiemove all tyres periodically. 2. —lnspect rims, removing rust and giving a coat of stock black or similar solution.

3. —-Inspect the inside of the covers for pieces of foreign matter or small fractures of the carcase, due to concussion bruises incurred during running. 4. —lnspect the treads for small cuts, embedded flints and the like.

5. —lnspect the tubes for porosity, rust marks, damaged or leaky valves and loose particles. 6. —Refit the tyres and inflate to correct pressure. 7. —Test wheel alignment and steering connection, in order to ascertain whether any excessive play is to be traced between the stering wheel and in the movement of the wheel on the hub.

Dealers will quote a small inclusive charge for this service, a charge which will, no doubt, be saved over and over again by the extra tyre mileage achieved. Finally, test pressures once every week.