From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Load, inflation, and horsepower table for different tyre sizes and vehicle weights.
Identifier | ExFiles\Box 31\1\ Scan217 | |
Date | 2nd September 1914 guessed | |
LOAD, INFLATION, AND H.P. TABLE. TABLE DATA: Columns: Load per Wheel | Minimum Inflation Pressure in lb. per square inch (under different conditions of loading) for tyre sizes: 80 m/m, 85 m/m, 90 m/m, 100 m/m, 105 m/m, 120 m/m, 135 m/m | Maximum H.P. of Engine | Maximum Weight of Car Unloaded | Section of Tyre. Cwts. | 80 m/m | 85 m/m | 90 m/m | 100 m/m | 105 m/m | 120 m/m | 135 m/m || H.P. | Weight | Tyre Section 2 | 54 | — | — | — | — | — | — || 2½ | 57 | 52 | — | — | — | — | — || 10 H.P. | 16 cwts. | 85 m/m 3 | 60 | 55 | — | — | — | — | — || 4 | 66 | 61 | 56 | — | — | — | — || 5 | — | 67 | 62 | 57 | 54 | — | — || 12 H.P. | 20 cwts. | 90 m/m 6 | — | — | 68 | 63 | 60 | 53 | — || 7 | — | — | 74 | 69 | 66 | 59 | — || 20 H.P. | 26 cwts. | 105 m/m 8 | — | — | — | 75 | 72 | 65 | 58 || 9 | — | — | — | — | 78 | 71 | 64 || 30 H.P. | 32 cwts. | 120 m/m 10 | — | — | — | — | — | 77 | 70 || 11 | — | — | — | — | — | 83 | 76 || 60 H.P. | 40 cwts. | 135 m/m and upwards 12 | — | — | — | — | — | — | 82 || 13 | — | — | — | — | — | — | 88 || 14 | — | — | — | — | — | — | — || 15 | — | — | — | — | — | — | — || It is important that tyres should not be loaded above the capacity of the section in use. The advisable maximum load on any one wheel is that corresponding to the pressure heavily underlined. Thus tyres of 105 m/m section are best not loaded above 8 cwt. per wheel, pressure being 72 lbs. In emergency, 105 m/m tyres may be loaded to 9 cwt. per wheel, but pressure should be raised to 78 lbs. WOOD-MILNE LIMITED, PRESTON. We recommend the use of the WOOD-MILNE Foot Pump to ensure correct inflation. | ||