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Show GIVE AUTO TIRE GOOD ATTENTION Very Few Owners Give a Thought to Its Care, With Exception of Inflating It. COTTON FABRIC FOUNDATION Elimination of Internal Friction Would Greatly Increase Life of Cover-Big Cover-Big Difference Between Cords and Fabrics. To the average owner, an automobile automo-bile tire Is good only when It travels many thousands of miles without breaking down or blowing out. Very few give a thought to Its care, with the exception of lnflntlng It from time to time, and a still smaller number know what It Is made of. A big tire concern has prepared a treatise on the foundation of one which should be remembered by every motorist. It Is as follows: "Cotton fabric Is the foundation upon up-on which an automobile tire Is built. It Is used to give stability and strength. There are two well-known classes of tires the square-woven fabric and the cord tire. Cords and Fabrics Differ. "In the square-woven fabric tire the threads In euch ply run In both directions, direc-tions, alternating over and under as in a piece of ordinary cloth. In the cord tire, the threads or cords In each ply run parallel, with the exception of a few small cross threads, used simply to bold the cords together while they are being Impregnated with the rubber compound. "The life of a tire would be greatly increased if Internal friction could be eliminated. The Internal friction caused by intermittent distortion of the tire in use Is the result of the friction fric-tion of the threads upon each other and the strains and stresses set up In the rubber compounds. Naturally the fabric which gives the least room for Internal friction will give the longest life to the tire. "Since square-woven fabric cannot be thoroughly impregnated with rubber at the points where the threads cross, flexing at these points will cause a sawing action and the generating of Internal heat. It has been demonstrated demonstrat-ed very clearly by experiment that when the temperature resulting from. Internal heat reaches 230 degrees, vulcanized vul-canized rubber ceases to function as an adhesive compound, crumbles Into minute particles which fall to resume their original condition, causlug the compound to lose its function In the tire. Heat Spoils Rubber. "This causes separation, weakness, und finally a blowout. It mny be Interesting Inter-esting to know that 205 degrees is not an uncommon temperature readied in a tire when driven at a high speed over the road; this Is particularly true of large truck tires. "In the case of cord tires, each thread Is Imbedded In the rubber compound com-pound and the Internal friction Is reduced re-duced to a minimum. A brief summary sum-mary of the advantages derived from the use of cord tires would Include easier riding, due to greater resiliency resili-ency ; saving of gasoline and oil ; saving sav-ing of machinery, and more miles per dollar." |