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).
Frame stiffness, the testing of a new tie-rod, and gearbox design considerations between the 20 HP and 40/50 chassis.
| Identifier | ExFiles\Box 6\4\ 04-page155 | |
| Date | 1st November 1925 | |
| To Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to CJ. DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} R7/MS.11.25. X5310 X. 8380 X. 8310 X. 5310 I have asked DA.{Bernard Day - Chassis Design} to arrange for you to test a tie-rod of increased dia. We are not sure that the tie-rod permanently stretches, but naturally it would temporarily stretch with the load, but we hear from DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} that the body troubles are not due to the vertical deflection of the frames, but entirely due to cross winding and lateral deflection. I am not sure that I agree with this, but think we also suffer from troubles that could be reduced by greater vertical stiffness. In our present frames, and especially in the newer ones, we believe it will be found that the twisting and lateral flexibility is good compared with other makes, because we use a much larger number of fairly substantial tubular cross members, and it is for the object of maintaining the lateral stiffness that we desire to keep the gearbox a separate unit from the engine. It also facilitates any work that may be necessary on the clutch. I shall be pleased to hear from you whether this convenience is one that we ought not be abandon. At the same time this view would be quite different when discussing a smaller chassis like our 20 HP., in which case the taking down of the gearbox is a less series matter, and its interference with the frame also. I do not however think we can with advantage redesign our 40/50 gearbox on the lines of the 20 HP. and materially reduce its weight. R.{Sir Henry Royce} | ||