TYRE EVOLUTION.

Auckland Star, Volume LXIII, Issue 139, 14 June 1932, Page 14

TYRE EVOLUTION.

PRINCIPLE UNCHANGED. OLD PRACTICES REVIVED. IMPROVED DURABILITY. Superficially a modern motor tyre look very much the same as those that were produced 10 years ago, but the mileage results obtained to-day prove that there must be very great differences. There has been 110 change in the fundamental principle of the pneumatic tyre as first evolved in 1888, but as the outcome of research and experiment, the whole science of tyre design and construction is now better understood. This has led to improvements of various kinds, and incidentally to the reintroduction of early practices, notably the wired-on type of attachment on the well-bdse rim, and cord casing, which were abandoned a quarter of a century ago, but have since been proved to be better than the ideas that for a time superseded them. Cycle tyres were being made in England and Australia •with cord casing away back in 1805. Even in 1901 a company in Australia made motor tyres with cord casings, yet the early development of motoring saw cotton coid discarded for a cross-woven

canvas. This wa,s adopted and used universally until about 1920, when with the evolution of the low-pressure tyre, the long discarded cotton-cord fabric was brought hack into general use for tyre construction. In pre-war days very little attention was given to tread pattern. Cross grooves in the tread and metal studs were sometimes used, but many tyres were made with plain treads. In later years much effort was directed on the evolution of a tough rubber non-skid tread, now recognised as a matter of considerable importance. Primarily its aim is safety, 'but it does more than that, because owing to its providing better traction, road slip is eliminated, resulting in increased tyre life. Rubber alloys have been evolved, that will out-wear steel, resist cute, and stand up to hard work over mileages that were undreamt of a few years hack. Some of the mileage figures reported from time to time hy car and truck owners, reaching as high as 96,000 miles with Australian made tyres on motor trucks, driven under ideal conditions, arc well nigh incredible. But while these abnormal mileages are of interest, the important fact is that every owner of an automobile, who gives attention to proper inflation is obtaining treble the mileage that was obtainable ten years back, and at only about one-third of the initial outlay. 'Thus have tyre manufacturers helped to reduce the cost of automotive transportation and increase the serviceability of every type of motor vehicle.