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).
Vehicle suspension characteristics, detailing issues and modifications to dampers, axles, springs, and stabilisers during testing.
| Identifier | ExFiles\Box 97\4\ scan0179 | |
| Date | 23th November 1938 | |
| -8- Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux}3/R.23.11.38. The general suspension characteristics were such that journeys could be covered in comfort in a time which would be difficult, dangerous and uncomfortable in the present standard Bentley. The ride appeared at least as good as Wraith in spite of 15 m.p.h. higher top speed. No road surface was encountered on which it was necessary to reduce speed on the grounds of comfort. The low speed ride was also good. The range of the damper control, 0 - 30 lbs., to the rear dampers only, proved adequate for all conditions encountered, and the maximum was only required under very extreme circumstances. The rear axle was inclined to patter on some types of choppy surface. Balanced damper valves are to be tried to overcome this. The bottom rubbers of the rear damper links collapsed. When this occurred the axle patter was more pronounced. An improved design is at present being tested on the bump rig. The poundage of the front dampers varied. During the running due to the valves sticking, and damaged replenishing valves and a broken connecting link F.B.3409 resulted. The trouble was attributed to the position of the leak holes in the valves. These were modified to instructions received from the works, a new connecting link and replenishing valves were fitted, and no further trouble was experienced during the last 3,414 miles running. Softer front bump buffers were fitted and covered 11,587 miles. The centre bolt in the N.S.R. road spring failed apparently due to the interleaving bedding down and allowing the spring bolts to become loose. These should in future be tightened down after the first fifty miles running as on production. A new bolt was fitted and the bolts of both springs were tightened down. No trouble was experienced during the remaining 11,500 miles and the bolts remained tight. The front stabiliser was satisfactory and the rating just sufficient to keep the roll down to reasonable proportions. | ||