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).
Front axle wobbling issues on the 20 HP model, referencing solutions involving different tyre sizes and steering components.
| Identifier | ExFiles\Box 29\1\ Scan299 | |
| Date | 3rd May 1927 | |
| To DA.{Bernard Day - Chassis Design} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} +457 Hs{Lord Ernest Hives - Chair}/Rml/LG3.5.27. 20 HP. FRONT AXLE. Y5420 X5810 With reference to DA{Bernard Day - Chassis Design}3/M30.3.27. Lightening the front axle on the 40/50 HP. did raise the critical wobbling speed somewhat, but the tendency to wobble at the critical speed did not seem sensibly diminished. This, in our opinion, was due to the all round lightness of the steering with the new axle. With 6.75" or 6" tyres, the critical speed is well within the car range even with recommended tyre pressures. You will recollect the difficulty experienced with 12-EX when 6" tyres were fitted at the commencement of the test with the new axle. The trouble was eliminated with the spring loaded cross steering tube and 6.75" tyres. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||