March 1, 1920] 



THE INDIA RUBBER WORLD 



MiTEEIAI.. 



See General Specifications. 



(a) Cord Material shall be of the best quality combed Sea 

 Island cr SakcUaridcs cotton or their physical equivalent as 

 approved. 



(b) Rubber Comi'oind: 



New Rubber 

 Per Cent 

 Volume. 



Tread minimum 70 



Side wall minimum 65 



Friction and cushion minimum 85 



TESTS. 



See General Specifications. 



(a) Measurements: Cross-sectional diameter of each tire in- 

 flated to recommended weight and load schedule of the S. A. E. 

 shall be: 



Sile in inches 33 by 4 35 bv 5 36 by 6 38 by 7 40 bv 8 



Diameter 4.2 5.4 6.3 7.35 8,4 



(b) Tires shall- be capable of withstanding water pressure of 

 350 pounds per square inch without injury. 



(f) Minimum Strength of the casing (strength factor) is the 

 product of the number of cords per inch measured at the tread 

 at right angles to the cords, multiplied by the strength of the in- 

 dividual cords as taken from the cord casing, muhiplied by the 

 number of plies : 



Siie in inches 33 bv 4 35 by 5 36 by 6 38 by 7 40 by 8 



Strength factor in pounds. 2,000 2,500 3,000 3,500 4,000 



(rf) Friction: 



Pounds. 



Strength of union between breaker and tread minimum 32 



Strength of union between breaker and cushion minimum 32 



Strength of union between side wall and plies minimum 14 



Strength of union between cushion and plies minimum 16 



(e) Rubber Compound: 



Tread. Side Wall. 



Minimum. Minimum. 



Ten.«le strength 2,400 1,500 



Ultimate elongation inches 2-12 2-11 



'stretch inches 2-10 2-10 



Set per cent 25 25 



(f) Road Test: Manufacturers shall maintain at least two 

 cars used e.xclusively for test and they average at least 1.000 car 

 miles per car week for sizes 33 by 4 inches and 35 by 5 inches ; 

 and 500 car-miles per car per week for 36 by 6 inches, 38 by 7 

 inches, and 40 by 8 inches. A sufficient number of casings (not 

 less than six) for sizes 33 by 4 inches and 35 by 5 inches and not 

 less than four for sizes 36 by 6 inches, 38 by 7 inches, and 40 by 

 8 inches shall have averaged on the rear wheels at least 5,000 



INSPECTION. 



See General Specifications. 



PNEUMATIC INNER TUBES (GRAY). 



GENERAL. 



(o) This specification covers requirements for pneumatic inner 

 tubes of the endless type, except motor cycle tubes, which shall 

 be butt end or endless, as ordered, of the following sizes : 



GS 1040 28 by I'i inches 



GS 1041 28 by 1% inches 



GS 1042 28 by 3 inches 



GS 1043 29 by 3> a inch-s 



GS 1044 30 by 3' j inchss 



GS 1045 31 by 4 inches 



GS 1046 33 by 4 inches 



GS 1047 35 by 6 inches 



GS 1048 36 by 6 inches 



GS 1049 38 by 7 inches 



GS 1060 40 by 8 inches 



(b) See General Specifications for Tires which are a part 

 hereof. 



CONSTRUCTION, 

 (a) Gages: Tubes shall conform to the following table: 



Medium Pole Minimum Minimum Fin- 

 Size. Thickness, ished Length. 

 Si7e. Inches- Inch. Inches. 



28 by I V^ 1 0.048 77 



28 by IM ; .048 77 



28 by 3 i% .072 77 



29 by 3/2 2<4 .090 78 



30 bv 3H 2'.i .090 81 



31 bv 4 2'/i .095 82 



33 by 4 2i/i .110 89 



35 by 5 3 .135 92 



36 by 6 i'A .180 92 



38 by 7 4"4 .210 94 



40 by 8 5 .250 96 



(b) If tube is mold cured, measurements must be equivalent to 

 above as determined by volume, and if larger size poles are used, 

 volume of rubber shall be at least equal to above measurements. 



(c) The splice shall be as strong as the rest of the tube under 

 the inflation test. 



((/) Each tube shall be properly fitted with one complete 

 Schradcr valve or its approved equal, and not leak or tear out 

 under ordinary usage, as follows : 



Schrader's No. 

 or Approved 

 Size. Equal. 



28 by 1!^ 1022 



28 by IH 1022 



28 by 3 1936 



29 by 3 J^ 1936 



30 by 3^^ 725 



31 by J 725 



33 by 4 725 



35 by 3 792 



36 by 6 2033 



38 by 7 2033 



40 by 8 2033 



Each valve shall be fitted with lock nut, rim nut, valve cap, 

 and dust cap, with exception for sizes 28 by 3, 29 by S'A, 36 by 6 

 and over. Spreaders shall be furnished for all sizes up to and 

 including 25 by 5. 



MARKING. WRAPPING AND PACKING. 



See General Specifications. 



Wrapping and packing shall conform to requirements accom- 

 panying requests for bids. 



MATERIAL. 



See General Specifications. 



Shall be made from a compound containing 93 per cent by 

 volume (minimum) new rubber; sulphur content shall not ex- 

 ceed 7 per cent and organic acetone extract of the cured com- 

 pound must not exceed S'A per cent of the weight of new rubber 

 used. 



TESTS. 



(a) Rubber compound: Test pieces shall be !4-inch wide over 

 a gage length of 1 inch, the ends being gradually enlarged to a 

 width of approximately 1 inch, to provide a satisfactory gripping 

 surface. 



Ultimate elongation inches 1-8V4 



Set: 



Stretch inches 1-6 



Stretch percent 10 



(b) Each tube shall be tested for leaks by inflating with air 

 and immersing in water. 



INSPECTION. 



See General Specifications. 

 Each lot of 1,000 tubes or less shall be tested. 

 (To be continued.) 



TIRE AND AUTOMOBILE "SATURATION POINT" NOT IN SIGHT. 



With motor vehicle registrations in the United States well past 

 the seven million mark, certain "croakers" are writing much 

 about the "saturation point" and that other indefinite period when 

 the automotive industries must face "diminishing returns." 



W. O. Rutherford, vice-president of The B. F. Goodrich Co., 

 .^kron, Ohio, scoffs at such pessimism, however. Automobiles, 

 he points out, come in the "consumption" class of commodities ; 

 that is, they are used, worn out and replaced just as clothing is. 

 He forecasts that we shall be able to absorb not only the present 

 automobile production, but shall even sustain the greater growth 

 which ambitious manufacturers are meditating. Continuing, he 



So far as passenger vehicles are concerned we arc now at the 

 the crest of a buying market. Production does not equal de- 

 mand, and personally, I expect this condition to exist for some 

 time to come. I recall being told at one of the New York shows 

 way back in 1907 that the then annual production of 60,000 cars 

 marked the peak point in automobile manufacture and that the 

 number of cars to be made annually would lessen rather than 

 increase. Just as that prophet of gloom was suffering from 

 brainstorm, so will I also classify those who today are refusing 

 to advance with the times. The proposed car production for 

 1920 is 3,000,000 cars. An analysis of the market, at home and 

 abroad, shows an ability to absorb even greater production, hence 

 the possibility of a shortage of cars is imminent. 



