LENGTHENING TYRE LIFE

Hawera Star, Volume L, 29 November 1930, Page 13

LENGTHENING TYRE LIFE

HOW I\> SET ABORT I'l

The service which a tyre gives is vei v largely in the hands of its owner. Careful driving means long lile; thoughtless or bad driving means a short and by no means a iiappv life. Raipiid (acceleration and deceleration are both fatal to a long life, as thej impose a strain upon cover and tube alike which no rubber can withstand. The latter is more common than the former, because it is more easy of accomplishment owing to the efficiency of the braking system. To apply the brakes suddenly means that the friction between the tread and the road surface is increased a. tliousaiidloid, and many shillings may be knocked oft the value of the cover every time it happens. W'henei er a road which is under repair has to be traversed particular care should be taken, for racing over a patch of unrolled or partially rolled road metal may result in a multiplicity of cuts appearing on the covers. Take a stretch of stony road at eight miles per hour on low gear, and the covers will come out of the ordeal unscathed; take it at fifteen miles per hour on top gear and much serious damage may accrue. The reason for this, of course, is that when low gear is engaged the movement is even, but when travelling slowly on top gear the car is propelled by a series of more or less sudden jerks. It is the unevenness of the movement that causes the damage.

It is a great mistake only to test the pressure when the tyres 1-ook flat, as so many are in the habit oi doing. Tyre makers state definitely that for certain cars the pressure should he so-and-so. If their advice he disregarded and a lower pressure be maintained the rate of wear'will be accelerated. It is perfectly true that an under-inflated tyre gives more comfort to the car occupants, but it is a case of securing comfort at a high cost. Under-inflation in a low pressure tyre is more serious than in a high pressure. Say the normal, pressure—the maker’s recommendation —should be 251 b per square inch for a given balloon tyre and 801 b per square inch for a high pressure tyre to fit the same wheel and carry the same weight. If the pressure be too low by slb it is a drop of 20 per cent, in the former case and only about 6 per cent, in the latter case.

It is not only when the' car is actually running that attention should be given to the tyres. They should also be carefully looked after when m the garage. With tyres, as with many other parts of the machine as a whole,

it is the frequent inspection and attention which reduce excessive wear and tear Every week or so, or more frequently if the ear is constantly on the road the exterior of each cover should he minutely examined for the presence of pieces of grit, glass and other foreign substances. Ibeso should lie removed with a pointed piece of wood, tlie cut washed out with a little petrol, and filled with special solution sold for the purpose. In the event of the cut being a large one, o-ive two applications of the solution and finally fill in with cement. Another essential duty is to examine the inside of the rims for rust whenever a tvre is being changed. Water often finds its way below the cover, rusting the rim and rotting the fabric lining of the cover. Remove all rust and paint with rim enamel. Check and correct tlie alignment of the wheels periodically, so that the wheels will always roll with the minimum of friction and the tyres will mot be subject to friction across the direction of travel.