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).
Road test report on steering vibration issues and subsequent investigations.
| Identifier | ExFiles\Box 96\1\ scan0249 | |
| Date | 7th January 1938 guessed | |
| -2- (the type prior to the present type). These were fitted as spares. I tested the steering wheel for slackness, there was no free movement. A road test was then taken Messervy and the chauffeur accompanying me. I took the North Road. The steering felt on the heavy side at medium and up to 80 m.p.h. At 70 m.p.h. there was an irritable vibration from the steering column and wheel. The steering wheel at this speed was nibbling all the time. There was no sign of a wobble or the feelings of a wobble. I pointed this out to the chauffeur who agreed that it was not a wobble that was being complained of, but the nibbling and vibration as already mentioned. I also noticed that at the time the vibration came on it could be felt from the suspension. The front of the car was riding hard irrespective of the damper control position. The car was taken to a quiet place and the front wheels removed. The balanced Dunlop wheels were fitted, and the same test piece of road was used. The steering was perfect, no vibration, absolutely steady, and the hardness of the front ride had disappeared. I requested the chauffeur to drive the car, and he admitted at once that he could not wish for a better steering. I got him to make a lengthy trial and the more he drove, the more emphatic he was with the result. He then admitted that he had been running with too low a pressure in his Englebert tyres, which had made the steering very bad. We returned to Cricklewood with the view of fitting the owner's two spare Dunlops to the front. In doing this we came upon a snag. We could not balance up the o.s.f. Investigation found that the brake drum and hub were considerably out of balance. We had to dismantle it and found the cause was partly dirt in the outer ridge, and after cleaning that out, the drum itself was approximately one ounce out of balance. As this was a particular job, I would not fit it, and found a similar drum that was right, this was fitted. The wheels were balanced up and pressures checked 35 lbs. These tyres were the latest 90 type (not cut). I am drawing attention to this because on the road, the steering was not so good with these tyres as with the previous ones we had tried. The difference being the open sides as against the closed sides. I made the remark that the other type of 90 tyres was the steadier. Cont'd.{John DeLooze - Company Secretary} | ||