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).
Issues and suggesting modifications for the 20 HP side steering tube.
| Identifier | ExFiles\Box 56\4\ Scan012 | |
| Date | 15th September 1926 | |
| X5450 To DA.{Bernard Day - Chassis Design} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}5/LG15.9.26. 20 HP. SIDE STEERING TUBE. We note that on N.sch.2258 you have provided a maximum variation between the centres of the pendulum lever and the steering arm ball ends of .600 in either direction. In addition, the effective rating of the springs (both ends of the tube being considered) is 1500 lbs. which we have found to be quite satisfactory in our recent tests. On N.sch.2067 however, the distance between the pendulum lever and steering arm ball ends can only vary by .150" in either direction and the effective rating of the springs (being at one end only) is 2200 lbs. We suggest that the 20 HP. tube should be altered to give conditions approximating those found to be successful on the 40/50 HP., that is that the ball end movement should be increased and the spring rating reduced. Personally, we are under the impression that owing to the better road holding qualities of the 20 HP. and its lighter steering, the effective rating of the springs in the side steering tube might be somewhat less than 1500 lbs. Our own experience of too little movement in the spring control ball ends is that on very bad roads the ball pads come up against their stops and very violent shocks are transmitted to the driver. The complaint of joggles on the 20 HP. steering is one which we are frequently having to deal with, and we feel that some modification is urgent to overcome the trouble. Hs{Lord Ernest Hives - Chair}/B. | ||