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).
The testing and comparison of different rear spring types, their weights, and performance on car models 12-KX and 15-EX.
| Identifier | WestWitteringFiles\S\March1928-May1928\ Scan150 | |
| Date | 1st May 1928 guessed | |
| contd :- -2- amplitude rear spring movements had something to do with this. With reference to the lighter type of rear spring fitted to 12-KX for test. This type of spring is illustrated in F.78615. Its weight is 64 lbs. The corresponding standard spring weighs 82 lbs. Actually 12-KX was not the right weight for the springs fitted; they were only incorporated to obtain a figure for durability for the type. We do not know whether interest in this spring still continues, but it might be useful to use it as our standard 25% stiffer type i.e., it lowers the car 1" and saves weight with the same stress as standard owing to its reduced deflection. Certainly our experience on 15-EX has shewn us a stiffer spring is an advantage on cars such as the Barker open touring illustrated in last weeks 'Auto car'. We have satisfied both Summers & Skinner - open touring car drivers - with stiffer springs after they had complained of the Standards. Hs{Lord Ernest Hives - Chair}/RM.{William Robotham - Chief Engineer} | ||