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 for front and rear car spring weights for the 20/25 Hp model from Firths Springs.
| Identifier | ExFiles\Box 106\1\ scan0303 | |
| Date | 6th November 1931 | |
| x 5410. 6.11.31. x4429 20/25 Hp. CAR SPRING WEIGHTS. (FIRTHS SPRINGS.) 1.Front springs. High Rating Medium Rating Low Rating Spring. Springs. Springs. Drawing No. F-57735. F-56511 F-57900 Piece No. F-57739 F-57617 F-57902 Type. 750lbs 750lbs 700lbs Loaded lbs 752-758. 766lbs 712lbs Loaded cam- .65"neg. Flat. .5"Pos. ber. Initial cam- 1.05"-1.06". 2.25" 4.50". ber. Length. 38" 38" 38" Weight. 21.5lbs. 28 lbs. 22 lbs. 11.Rear Springs. High Rating Medium Rating Low Rating Springs. Springs Springs. Drawing No. F-57729 F-57192 F-57904 Piece No. F-57731 F-57195 F57906 Type. 900lbs. 900lbs. 1000lbs. Loaded Lbs. 947-948 932 1008 Loaded cam- 1.41" .5" neg. .5"Neg. ber Initial Cam- 2.38"-2.39" 4.625" 6.00" ber Length 56" 56" 56" Weight. 45.5lbs. 55lbs. 53lbs. | ||