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).
Calculation of spring poundages for a Silver Wraith Enclosed Limousine.
| Identifier | ExFiles\Box 109\1\ scan0008 | |
| Date | 15th June 1938 guessed | |
| APPENDIX PART 3. To compute the Spring Poundages front and rear for Silver Wraith 1st.Enclosed Limousine, and finally for the heaviest car. 26-G-VI.- Weight of car cwts. qrs. lbs. Weight of car = 39 1 14 Front = 18 1 14 Rear = 21 0 7 Ratio front to rear = 18.375 to 21.062 Weight of Silver Wraith car unladen = 37cwt.3qrs.10.lbs = 4238 lbs. therefore front wheel load = (18.375 / 39.437) x (4238 / 2) = 986 lbs. therefore rear wheel load = (1.000 / 1.914) x (4238 / 2) = 1133 lbs. Allowance for 5 passengers + 100 lbs of luggage. 2 front seat passengers = 300 or 75 lbs on all four wheels. 3 rear " " = 450 or 225 " on each rear wheel 100 lbs. of luggage equals 50 lbs on each rear wheel. Laden wheel loads = Front 986 + 75 = 1061 lbs. Rear 1133+75+225+50 = 1483 " Unsprung weight of Silver Wraith. Front = 130 lbs. Rear = 200 lbs. Therefore sprung weight per wheel Front = 931 lbs. Rear = 1283 lbs. The heaviest Body of 14 cwts. The increase of 1 1/2 cwts. would be disposed approx. 1/3 front and 2/3 rear, giving sprung weight per wheel: Front 959 lbs. Rear 1311 lbs. | ||