Arizona republican., 1918-10-13
''DOC" GATES TALKS
 TIRE PHYSIOLOGY

In a sense. tires are subject to as many ills as mortal man. Such being the case, why should not every effort be made to cure these ills, prolong the life of tires and cut tire up-keep in half. Tires are made of fabric and rubber; true, some tires are better than others, not alone because materials used are of superior quality, but rather because of a higher degree of effici- ency, combined with highly standard ized methods and equipment.
 To say the pneumatic tire is beyond the experimental stage is to infer that perfection has been reached. But such is not the case. The larger manufac- turers of tires and rubber goods main tain expensive experimental labora- tories presided over by highly experi- enced chemists. In conjunction with the chemist is the mechanical or manu- featuring research department. Com bined, these two units over the tire field from the rubber plant to the com pleted article. Therefore a few tire companies set the pace, as it were with the smaller and newer concerns almost entirely dependent upon their bigger brothers.
 What applies to tires, applies to tubes, but possibly to @ greater de- gree. It is true that il the best grades of tires and tubes absolute uniformity IS unattained, due almost entirely, no doubt, to the fallibility of man, yet the element of uncertainty is narrowed down in most of the standard makes. Other elements entering into variation of quality are to be found in the raw materials, compounds, etc
 It does not necessarily follow, just because certain make of tire is well known or has been in the market a long time, that it must be good. To be sure it ought to be, but often it is not The old saw, "a chain is no stronger than it's weakest link" might be changed to read that "a tire is no bet ter than the basis of adjustment under which it is sold" That may or may not be true, nevertheless it is worth considering as is also the standing of the agency through whom you make the purchase.
 Some of the more common ills to which tires are subject-some more than others-are as follows: Tread separation, weak sidewalks, checked fabric, stone bruises, sharp glass or stone cuts, sand blisters, nail pune lures, rim or bead cuts, blow -outs and old age. While all of these cannot be avoided, most of them can be prac- tically eliminated or deferred by care ful driving, frequent inspection and uniform air pressure on the basis of 20
 pounds to each inch of cross section
 That is, 3-inch tire, 50 pounds; 31b
 inch tire, 70 pounds; 4-inch tire. S(
 pounds pressure.
 A common mistake is to reduce tho
 air pressure, due to expansion caused
 by heating, unless the pressure is agair
 brought up to normal after the tires
 have cooled off.
 Countless experiments determined
 the present standard pressure for tires At these pressures and under varying conditions with reasonable and intelli gent care it was found a higher maxi mum of tire mileage or ton mileag' was obtained on a greatly increased average.
 Expert tire men can tell within hundred or two miles the mileage | standard tire has run. He can, or som of us can, tell the air pressure cak'rie, | within five pounds.
 | Under imitation causes more tire i'll | than any other one thing. Tread sep | aration issure to follow when the tire
 are run soft. Sidewalks are also weak
 ened and running flat not only de
 stroys the tube, but the tire as wei
 Blow-outs are very frequent after sue abuses often making junk out of tire before they have gone 1,500 miles an
 running an otherwise perfectly goo
 tube. Checked fabric is most frequent ly caused by overlooking the tire! This can be done at full imitation b
 overlooking the vehicle or at low infla
 ton by using tires that are too smal The oversized tires are the sures means of providing proper tire equip