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).
Rationalised programme for front suspension components and track widths.
| Identifier | ExFiles\Box 159\7\ scan0241 | |
| Date | 6th June 1939 | |
| 1375 1306 To Rm.{William Robotham - Chief Engineer}... from Ev.{Ivan Evernden - coachwork} c. By.{R.W. Bailey - Chief Engineer} c. Da.{Bernard Day - Chassis Design} c. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} c. Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} c. Da{Bernard Day - Chassis Design}/JD.{J. Draper - Frames} Re: Front Suspension - Rationalised Programme. At the moment we have two yoke pieces giving a front track of 56.26" and 58.5" respectively, with 6.500 x 16 wheels and 7.000 x 16 wheels respectively, the height of the car being the same for each yoke and the out-of-centre point, 2.170" and 2.420" respectively. As quoted in Da{Bernard Day - Chassis Design}/Ev.{Ivan Evernden - coachwork}1/N.17.5.39 if we were to put 7.5 x 16 wheels on the wider track cars the out-of-centre point would become 2.745" which we think we all agree would be prohibitive. An experimental set of pieces has been issued for testing an out-of-centre point of 1.050 on the narrow track with 6.5 x 16.000 wheels ( i.e. B.5). We confirm that when we make a new yoke to raise the wide track cars ( Silver Wraith and Silver Phantom) to get increased ground clearance, we must at the same time alter the stub axle so as to get an out-of-centre point of 1.325" and then produce a modified yoke for subsequent use on B.5. and the other narrow track cars which will take the new stub axle and will give an out-of-centre point of .750" with 6.500 x 16 tyres. In the meantime it is agreed that for Silver Wraith, Silver Dawn and Silver Phantom cars which we may wish to build we should use the existing wide track yoke and 7.000 x 16 wheels. The new reduced out-of-centre point pieces will be designed as soon as the test on B.5. pieces is completed. Ev.{Ivan Evernden - coachwork} | ||