MOTOR NOTES

Dominion, Volume 28, Issue 91, 11 January 1935, Page 13

MOTOR NOTES

Tires Stand Torrid Weather HOT TAR AND HOT SUN (By “Headlight.”) Bright, hot sunshine, such as that of which the Wellington district is having more than its usual quota this summer, softens and even melts some of the tar and bitumen surfaces which are the most popular permanent road finishes in this part of New Zealand Some conscientious motorists have been worried about the effect of these warm semi-liquids on their tires, remembering the sad results of leaving rubber in contact with oil or petrol too long. “Headlight” has been informed on the best authority that the mode-n driver has nothing to fear from hot roads, even in the most torrid weather.

The agents for one of the most wellestablishe'd and favourably-known brands of tire on the New Zealand market, state that they have never had a tire fail as the result of its picking up tar or bitumen from a road softened by the sun, the modern tire being heatresisting for all ordinary purposes. Heat is one of rubber’s worst enemies. The surface of a road cannot become hotter than the rays of the sun, and therefore the rubber suffers no more from running on a hot road than from being in the sun. The heat of a road is very apparent to a driver, but ne or she does not often realise that considerable heat is generated in the tires themselves during a long, fast non-stop, run, such as between Wellington and Palmerston North in three hours. The maker does realise this, ami to make a good tire must provide for it not only by making the casing strong, but also by mixing compounds with the rubber. so that it will not be easily affected by heat.

Pavement Cooks Tire. Instances of tire failure as the result of their being subject to greater heat than had been anticipated by the makers have come to the notice of the firm consulted, but in each case it has been due to an accident. In one case the car had been allowed to stand on a pavement just after it had been laid and while it was still hot, and in another a wheel had been allowed to rest on a sheet of metal which had been used in the spreading of the paving material and so become hot. In each case the rubber received a second cooking, so that a section of the tread became doughy, and objects from the roads the tire rolled over afterward embedded themselves in it. Later the section went hard and fell off. Similarly, tires which had been scorched in a. fire in the premises in which they had been stored were ruined for life, their subsequent careers being of varied duration. The heat to which the tires ■were subjected in these cases, however, would be much greater than that of a road softened by the sun.

It was the custom for drivers in former years to shade the tires of a car from the sun when it was standing still, and occasionally this is still done, but such precaution with modern balloon tires is probably not worth while. The heat expands the air and increases the pressure, but this is not serious when tires are pumped to only a third of the pressures formerly advised. As for the effect of the sun directly on the rubber, while it probably is to some extent detrimental to the surface rubber the deleterious effect upon the casing as a whole is thought to be negligible, v

Sun May Correct Fault. . The authority referred to stated that no special precautions were taken with the tires on the firm’s own vehicles, which, although standing in t’ae sun frequently for long periods, and running over all sorts of roads in the southern half of the North Island, lasted for 20.000 miles in the case of a full size car and seventeen of eighteen thousand miles in the case of vans. He expressed the opinion that, after the sun had expanded the air, most tires were probably running at the pressure advised by their makers, under-inflation being such a common fault. .

It appears that, bn the whole, drivers need worry little about fancied causes of injury if they obey the well-known rules that tire makers never seem to tire of drumming into the motoring community.

RALLY PLANNED Tours to Wanganui As a test of ability to drive a motorcar over New Zealand roads at a given average speed, and to have it at the end of the journey in good condition, a motor rally, stated to be the first ever held in the Dominion, is being organised in conjunction with the Wanganui February carnival. The competition is similar to a motor-cycle test, but average roads are traversed at normal speeds and stock is taken of the condition of the cars at the end. Like the motor-cycle test, a rally is not in any sense a race.

A motor rally is the “rallying” of motorists at a given point after completing specified journej’s. The dates of the Wanganui rally extend from Saturday. February 23, to Monday, February 25. Nine starting places have been specified (Wellington, Palmerston North, New Plymouth, Wanganui, Auckland, Hamilton, Rotorua, Gisborne and Napier). Competitors will start from these points and travel to Wanganui by nine different routed, all of which will pass through Napier on the Saturday night, thus permitting the competitors to congregate there after completing their first day’s journey. The basis of the competition lies in the awarding of marks for arriving at the destination in the time specified and with a car as near to perfect in condition as it is possible to have it. Competitors who arrive too early will lose two marks per minute for every twenty minutes in excess of five. If too late they will lose one mark per minute for every minute in excess of ten. A table of penalties for faults in the condition of ears has been framed. The routes and times have been arranged as follow :— 1 Wellington.—via Palmerston North-

Taihape-Napier-Taupo-National ParkWanganui, 517 miles, to' be completed in 26J hours. Palmerston North.—-via Wanganui-Taihape-Napier-Taupo-National ParkWanganui, 500 miles, to be completed in 27 i hours. New Plymouth.—viaTaiha.pe-Nap ier-Taupo-National Park-Wanganui, 523} miles, to be completed in 27 hours. Wanganui—via Taihape-Napier-Taupo-Taihape-Wanganui, 513} miles, to be completed in 28} hours. Auckland.—via Taupo-Napier-Tai-hape-Wanganui, 506} miles, to be completed in 28 hours. Hamilton.—via Waikn remoana-Na-plef-Talhape-Wangannl, 469 miles, to be completed in 27 hours. Rotorua^—via Waikaremoana-Na-pier - Taupo - Raetihi - Wanganui, 495 miles, to be completed in 28 hours. Gisborne. —via Opotiki-Whakatane-Rotbrua-Taupo-Nap'ier-Taihape - Wanganui, 508 miles, to be completed in 26} hours. Napier.via Gisborne-Napier-Taihape-Raetihl-Wanganui, 505} miles, to be completed in 28} hours. The time limits are approximate only aud will lie varied as regards horsepower. GRUESOME FILM Punishment For Reckless. Shrieks, groans and horrified gasps filled New York’s Traffic Court when 200 persons summoned for motor offences found, themselves compelled to sit through a film representing motor accidents in gruesome ami horrible realism. The air was filled with the smashing of metal against metal and ’he wails of victims as picture after picture of road accidents was shown. Cars smashed into one another at crossings or whirled madly over cliffs. People were killed or maimed in all directions. Traffic offenders cowered and shivered as a pitiless voice from the screen pointed the moral of each accident: “Death has come to that man and woman in the car as it will come to you if you drive like a fool. “They are where time matters no more, and you will be. too. unless you take more care.” Meanwhile, the magistrate sat among the audience noting approvingly the success of his method of making the punishment fit the crime. Women offenders sobbed or shrieked, and men mopped,their brows or shifted uneasily in their seats. When the lights were switched on and the screen rolled up the magistrate took his place on the Bench and imposed the lightest possible lines on the offenders in consideration of the mental punishment they had already suffered. Court officials said this film show was the most effective piece of safety-first campaigning yet devised. Transport Minister Hore-Belisha should meet Magistrate Farrell (comments the London “News-Chronicle”). Tn the Wellington Magistrate’s Court