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).
Steering road shocks, geometry, and comparing design elements with Cadillac vehicles.
| Identifier | ExFiles\Box 173\1\ img101 | |
| Date | 25th January 1934 | |
| -2- Hs{Lord Ernest Hives - Chair}/Les.19/KW.25.1.34. Steering road shocks are considerably worse than a standard car. We hope the improved geometry of the 3 piece X steering tube will overcome this fault. To save adding extra ball ends we shall guide the centre part of the X steering tube in bushes. 27-EX steering, although it becomes hard work on locks when parking, has less self-centring effect on the open road than usual. By having a set of shorter bottom links we can try the effect of reduced transverse pivot lean. We imagine a little more backward pivot lean would help self-centring. At the moment there is 1.5° backward lean. Can you find out what Cadillacs use ? From your letter of the 10th it would appear that we are wrong using links of similar length. Personally it appears hard to believe that the variation in track should be sufficient to cause impossible tyre wear. There are other reasons why General Motors may have adopted longer links at the bottom - (a) In order to get the X steering geometry correct and prevent splitting the X steering tube into 3 pieces. (b) Using coil springs outside the chassis the leverage would not be sufficient if they were as short as the top links. We presume the staggered arrangement for the Cadillac triangular brackets is purely in order to get the engine as far forward as possible. Your specification of Cadillac steering is rather astonishing. 2.5° seems a large out of centre point. Can you get any details re the steering ratios, particularly on locks ? Can you find out what damper loads are used: To us it appears that there is no need to allow for high loads. We notice from the pictures you have sent that the inertia controlled Delco dampers have a lever control fitted to them. Does this adjust the dampers, or alter the functioning of the inertia control ? Hs{Lord Ernest Hives - Chair}/ I.A.LESLIE. | ||