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).
Proposed modifications to the rear leaf springs for the Wraith 80 model.
| Identifier | ExFiles\Box 100\1\ scan0185 | |
| Date | 7th September 1938 | |
| Secret. 406 To Da.{Bernard Day - Chassis Design}. from Ev.{Ivan Evernden - coachwork} c. Rm.{William Robotham - Chief Engineer} By.{R.W. Bailey - Chief Engineer} Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} c. BY/HEB.{H. Biraben} By/NS.{Norman Scott} Da{Bernard Day - Chassis Design}/Ev.{Ivan Evernden - coachwork}6/N.7.9.38. Re: Rear Leaf Springs B.III, B.50, Wraith 80 - Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}3/R.6.9.38 - ? The B.III. was designed for 2.750 front bump and 3.000 rear bump under full load. The proposal in the above memo will raise the rear of the car 1.175" under this condition, in which case the rear of the frame will be .275" higher from the road than the front, and under ordinary running conditions with one up approximately 1.500" higher. We have had cars in the past with this characteristic and have disliked them as they appear to be preparing to nose-dive. We suggest that new front springs be produced raising the front .750" and increasing the bump under full load from 2.750" to 3.500", and reducing the rebound from 3.500 to 2.750" such as we have done on B.50 and Wraith 80, because the rear bump has been increased to 4.000". This would entail deepening the outside valances of both the front and rear wings on all cars not yet produced, and we suggest that revised schemes be sent to Messrs. Park Ward & Co. shewing this modification applied to 3.B.5. and 4.B.5. As the axle under all normal conditions will be lower relative to the body, and the wheel movement increased, the rear wheelarch sideways clearance may not be adequate to clear the tyre. There will be more toe-in of the bumped wheel on single wheel bump. The B.III. when fully laden will then be 1.000" higher than the B.2. as far as the front seat, radiator and roof are concerned relative to the ground. The ability to get out of the car without running boards will be reduced by approximately 1.000, but we see that it is no worse than the Cadillac 60 special which has no running boards. Ev.{Ivan Evernden - coachwork} | ||