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).
High-speed wobble issues on a 20 HP chassis, its potential causes, and a comparison with the Phantom model.
| Identifier | ExFiles\Box 47\5\ Scan070 | |
| Date | 26th August 1926 | |
| x448 BY5/H. 26.8.26. (RECEIVED 28 AUG 1926 Hs {Lord Ernest Hives - Chair} ) c. Hs. {Lord Ernest Hives - Chair} c. Hm. {Capt. W. Hallam - Head Repairs} 50-S-2. W.R.JAMES. Referring to FN10/DN. 24.8.26. and further to BY1/K. 27.7.26, freedom from high speed wobbles on the 20 HP. chassis is purely a relative matter. We agree that it is considered less liable to set up high speed wobbles than the Phantom, but we have had one or two 20 HP. chassis at least to which four wheel brakes were not fitted which had high speed wobbles in a pronounced manner. One of these is being run by a local man, having been bought second hand from Mr.Harrison of Birmingham. The present owner has complained bitterly on a number of occasions to the Repair Dept. of high speed wobbles. Apparently the original owner fitted balloon tyres and as a result of this, in combination with certain other factors peculiar to this particular chassis, high speed wobbles developed, with the result that I recommended the replacement of the balloon tyres with standard type. In regard to the suggestion that the fracture was due to an accident which took place in the hands of the previous owner, I cannot agree that this collision had any bearing on the case, in as much as any stress which is likely to have damaged the side steering tube would unquestionably have bent it, and bent it seriously, whereas no suggestion has been put forward either by Repair Dept. or from the owner that the side steering tube has been damaged in collision or modified as the result of a collision. It is quite possible for a low speed wobble, if persistent, and an unintelligent attempt to control same by hanging on to the wheel is resorted to, for the stresses to rise in the steering mechanism very high indeed. I understood from the Repair Dept. that the owner had complained of high speed wobbles. I may have been wrong on this particular point, and the wobble complained of may have been a low speed wobble, but in Contd. | ||