CAUSES OF TYRE WEAR

Sun (Auckland), Volume I, Issue 248, 10 January 1928, Page 6

CAUSES OF TYRE WEAR

CAREFUL DRIVING PAYS Interesting facts relating to the causes for rapid tyre wear have been compiled by the Goodyear company in its November magazine. To show the effect of braking severely a test was made with a truck driven at 35 miles an hour for 100 miles and braked to a stop, without skidding, every quar-ter-mile. One-half of the tread design was worn off in that test. Smaller wheel diameters were shown to result in decreased mileage. Three inches less diameter equalled a reduction of 91 inches in circumference, but meant a reduction of 22 per cent, in tyre mileage. Tyres on a car driven at 30 miles an hour consistently showed good mileage, but when the speed was increased to 45 miles an hour the mileage fell off by 50 per cent. Twentyfive per cent, of mileage was lost on tyres run under-inflated, and 45 per cent, on over-inflated tyres. Mechanical irregularities such as misalignment of wheels or rims on the wheel, bent spindles, wobbly wheels, or uneven brake adjustments took their toll in excessive tread wear. Fast driving also meant rapid tread wear. Rough road surfaces and hilly country were harder on tyre mileage than level territory and smooth roads.