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).
Road spring data including load on each wheel, loads on springs, spring rates, and roll ratings.
| Identifier | ExFiles\Box 111\3\ scan0097 | |
| Date | 19th May 1939 | |
| To Da.{Bernard Day - Chassis Design} from Rm{William Robotham - Chief Engineer}/FWK. c. to Da{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} c. to Da{Bernard Day - Chassis Design}/DB.{Donald Bastow - Suspensions} 3.B.50. Below are the road spring data obtained from the above car :- Front Suspension Coil springs FB.3947/8 900 lb. and 950 lb. respectively. Rear Suspension. Toledo woodhead. FB.1781 1050 lb. and 1100 lb. Load on each wheel. + driver. + 4 passengers. N.S.F. 943 lb. 1013 lb. O.S.F. 1085 lb. 1113 lb. N.S.R. 1112 lb. 1279 lb. O.S.R. 1154 lb. 1324 lb. Unsprung wt/front wheel = 130 lb. Unsprung wt/rear wheel = 205 lb. Loads on springs. (Measured at wheel) + driver. + 4 passengers. N.S.F. 813 lb. 883 lb. O.S.F. 955 lb. 983 lb. N.S.R. 907 lb. 1074 lb. O.S.R. 949 1119 lb. Spring Rates. N.S.F. 135 lb/in. = 6.0" U.L., 6.5" L. O.S.F. 137 lb/in. = 6.9" U.L., 7.1" L. N.S.R. 152 lb/in. = 5.9" U.L. 7.0" L. O.S.R. 162 lb/in. = 5.8" U.L. 6.9" L. Front Roll Rating. 334 lb/in (Corrected). = 2.65" U.L. 2.8" L. Rear Roll Rating. 153 lb/in (Corrected). = 6.1" U.L. 7.15" L. | ||