Bisbee daily review., 1920-07-04

Al the Jruck and JrdclOr meeting of the Society of Automotive Engin. eers held in Chicago a paper entit- led Relation of Solid and Pneumatic Tires to Motor Truck Efficiency was read by s. V. Norton, of the B. F. Goodrich Rubber company.
 The following is the last install ment of an abstract from his pa- per which has been pronounced by experts as the most authoritative treatment of the subject ever made MT. Norton is widely known as a transportation engineer, a tire ex- pert and as the author of Motor Trucks of America" and "The Mo. tor Truck as an Aid to Business Profits"
 Having reviewed the engineering features and the practical operating features in preceding installments of this series, let us now see what the operator faces in so far as tire ser vice is concerned. As the nature and eX.eat of service of the maintain anco and renewal of solid tires are well known, it seems unnecessary to comment on them except to say that years Of study and competition have developed this end of the business to nigh degree of perfection. so that the operator can depend upon many we'll equipped service stations for in stant attention, either in the day or night.
 "The manufacture of heavy duty pneumatic tires of six incli section and larger is, however, relatively new development, less than third of the manufacturers of passenger car tires have started actively to make heavy duty pneumatic truck tires, for they realize that the job of building tire which will stand up under the use and abuse to which it is subjected nowadays is not easy Moreover the task is not finished when the tire comes out of the heat CT It must be sold to the dealer, who, in turn, must not only stand behind the tire, but place himself in position to give the truck operator
 
 high-pressure air-pump, repair ma terial and rlolds for vulcanizing and in most cases a service car fo.' cmer- gency calls, as it must be remember cd the tire is apt to fall away from it's base and it cannot be driven home flat.
 'It may be said, without fear of contradiction. that the tire cOmpa- nies themselves are not as yet pre- pared tc give really efficient service III all parts of the country. In fact, even in the principal cities this phase of the business has not been fully developed Tn the smaller towns there are almost no airtanks or pumps to keep tires properly in- Hated. Pumps on trucks themselves are reported as not always dependa- ble. sometimes requiring from 15 minutes to half an hour to secure the desired pressure in d tire
 By far the most serious and diff ficult phase of giving service with heavy duty pneumatics, and that which causes the most concern to truck operators, is connected with the repair In fact, the chief com plaint in regard to pneumatic truck tires aside from their high initial cost, is that they are subject to in- juries, cuts and damage generally of such q nature that they cannot be repaired except at the factory where they are made, or in a few cities at factory brancn. and often they are damaged beyond all repair. This is not only expensive, but frequently necessitates the purchase of more than one set of spares should the first set be injured while the others are being repaired. Oftentimes the principal cost of punctures or blow outs is due to the necessity of laying up trucks awaiting new tires, due to stock shortage, or. sending the dam aged tires to the nearest factory branch for repair. Moreover re- paired castings frequently deliver but small mileage due to- the overcure of the joined portions. This danger is most difficut to overcome in the
  cure required to vulcanize the inte- | rior portion Of the new part of the | casing. No dought this feature will ! ultimately be corrected. 'r'he tread seems to give less trou- ble than the side walls which are more susceptible to rut wear and overlooking abuse. The movement toward the use of pneumatics should not be condemned | hokever, for undoubtedly it will be 1 the means of increasing the scope | of usefulness of motor transporta- | ton
 The question is too new to be de cided theoretically or from such i meager records as are now avail l able.
 The field of each type of tire may