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).
Specification sheet detailing loads on wheels and springs, along with spring rate data.
| Identifier | ExFiles\Box 154a\4\ scan0097 | |
| Date | 1st March 1939 | |
| -4- Rm {William Robotham - Chief Engineer} /FWK.5/JH.1.3.39. 2.B.50. Front springs. English Steel Open Coil FE.3947,8. Rear springs. Toledo Woodhead & interleaving. ..................... Loads on each wheel. + driver. + 4 passengers. N.S.F. 932 lb. 984 lb. O.S.F. 1045 lb. 1083 lb. N.S.R. 1092 lb. 1277 lb. O.S.R. 1061 lb. 1235 lb. Unsprung wt/front wheel 140 lb. Unsprung wt/rear wheel 205 lb. Loads on springs. (Measured at wheel). + driver. + 4 passengers. N.S.F. 792 lb. 844 lb. O.S.F. 905 lb. 943 lb. N.S.R. 887 lb. 1072 lb. O.S.R. 856 lb. 1030 lb. Spring rates. O.S.F. 142 lb/in Δ = 6.4"U.L., 6.65"L. N.S.F. 125 lb/in Δ = 6.32"U.L., 6.75"L. O.S.R. 155 lb/in Δ = 5.5" U.L., 6.62"L. N.S.R. 155 lb/in Δ = 5.7" U.L., 6.9"L. Rear roll rating 172.8 lb/in at wheel. Front roll rating 163 lb/in. at wheel. | ||