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).
Test results and stiffness calculations for an 1100 lb. front spring.
| Identifier | ExFiles\Box 43\2\ Scan206 | |
| Date | 6th July 1927 | |
| - 11 - The three loads for 1" above normal position. normal position. 1" below normal position. are first taken, moving continuously downwards. Then the spring is taken about 1" to 2" below the lowest position and the same readings are taken moving continuously upwards. Typical results for an 1100 lb. front spring are:- Down. Average. Up. Differences ---- ------- --- representing total static friction. ----------- ½" pos. 855 815 775 80 ½" neg. 1150 1100 1050 100 1½" neg. 1475 1415 1355 120 Stiffness in the first step is 1100 - 815 = 285 lbs/in. " " " second " " 1415 - 1100 = 315 lbs/in. Average stiffness is ~ 300 lbs/in. Spring is stamped "1100 - 300" OY. July 6th, 1927. | ||