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 sheet for spring loads on the 7-EX Phantom Car, specified for running in France.
| Identifier | ExFiles\Box 106\1\ scan0064 | |
| Date | 22th January 1926 guessed | |
| 7-EX - PHANTOM CAR. SPRINGS REQUIRED IF SPRUNG ACCORDING TO SCHEDULE FOR RUNNING IN FRANCE. FIXED CHASSIS LOADS. (As per chart). SPRINGS. FRONT. REAR. Near. Off. Near. Off. Spares, wheels etc. 896 946 693 793 VARIABLE LOADS. Body weight - 11 cwts. 190 190 436 436 4 passengers - 154 lbs. each. 93 93 215 215 1 cwt. of luggage on grid allowed for in fixed chassis loads. 1179 1229 1344 1444 ALLOWANCES. 50 lbs. off each front spring. -50 -50 100 lbs. not subtracted from rear springs owing to car going to France. 1129 1179 1344 1444 Cantilever springs rear. Sprung for 75% of load i.e. multiply by X 1.5 X 1.5 2 X 75 / 100 = 1.5 1129 1179 2000 2160 12 1/2% 12 1/2% stiffer.stiffer | ||