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 data table for Woodhead's 18.G.IV. Front off-side road springs for the 20/25 model.
| Identifier | ExFiles\Box 106\1\ scan0339 | |
| Date | 10th May 1933 | |
| Files. ----- X8210 10.5.33. ----- 20/25 ROAD SPRINGS. F.58604. Woodhead's, 18.G.IV. Front. The same tests as applied to Firth's springs were repeated, but since each of these Woodheads had a different number of leaves, detailed dimensions were taken of both springs. LABELLED OFF SIDE FRONT. Leaf Index No. | Load flat camber lb. | Defl. flat camber ins. | Length flat camber ins. | Average Thickness of leaf ins. Edge. | Centre | Length of taper α ins | Thickness at tip ins. Main | 58 | 2.800 | 38.062 | .178 | .176 | - | - 2 | 109 | 3.351 | 35.875 | .193 | .195 | .940 clips | .123 3 | 104 | 3.067 | 32.250 | .177 | .177 | 1.100 | .078 (.105) .080) 4 | 164 | 2.450 | 28.270 | .195 | .197 | 1.060 | .090 (.087) .073) 5 | 214 | 2.192 | 25.625 | .200 | .203 | 1.110 | .087 (.075) .052) 6 | 219 | 1.822 | 23.100 | .193 | .195 | 1.050 | .073 (.075) .052) 7 | 174 | 1.442 | 20.625 | .172 | .175 | 1.100 clips | .078 (.080) .056 8 | 224 | 1.138 | 17.950 | .177 | .176 | 1.100 | .078 (.080) .056 9 | 304 | .760 | 13.950 | .174 | .175 | 1.100 | .056 10 | 404 | .577 | 11.375 | .173 | .176 | 1.110 | .056 11 | 474 | .320 | 8.750 | .175 | .177 | 1.170 | .048 | ||