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 report and data for 20/25 HP road springs.
| Identifier | ExFiles\Box 106\1\ scan0343 | |
| Date | 25th April 1933 | |
| X5410 Files. 25.4.33. 20/25 HP. ROAD SPRINGS. F.57900. Firths. 750 lb. 18.G.IV. Front. These springs were tested as supplied direct from the chassis, the load being applied steadily up to 1250 lb. approx. 1.950 negative camber - and then removed steadily. The deflections of the K.1982 spring was also measured when the spring was bounced after the application of each load increase. The rig was set to give a shackle angle of 12° at flat camber. The results are shewn on Graph.1. The following particulars were also obtained from the K.1982 spring. Front K.1982. Leaf Index No. | Load Flat camber lb. | + Defl. flat camber ins. | Length flat camber ins. | Average thickness of leaf ins. | Length of taper ins. | Thickness at tip ins. | | | | At edge | centre | | Main | 145 | 2.570 | 38.000 | .220 | .217 | - | - 2 | 122 | 3.725 | 36.025 | .198 | .195 | 1.500 | .073 3 | 157 | 3.567 | 31.925 | .191 | .186 | clips | .060 4 | 170 | 2.587 | 27.825 | .193 | .188 | 1.500 | .060 5 | 195 | 2.030 | 23.725 | .185 | .180 | 1.500 | .078 6 | 260 | 1.624 | 18.850 | .184 | .180 | 1.500 | .080 7 | 320 | 1.172 | 15.950 | .174 | .171 | clips | .070 8 | 395 | .793 | 12.250 | .193 | .188 | 1.500 | .060 9 | 710 | .400 | 8.500 | .169 | .164 | 1.500 | .045 | ||