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).
Technical report detailing adjustments and improvements to vehicle suspension springs.
| Identifier | ExFiles\Box 43\2\ Scan141 | |
| Date | 8th May 1926 | |
| Oy1-E-5826 -3- May 8th, 1926 I.c (cont'd.{John DeLooze - Company Secretary}) This effect is illustrated on attached chart. d.{John DeLooze - Company Secretary} Rear Springs. The rear springs we are making here have the original stiffness standardized after the war, that is the initial camber is 2" and they are run with 1" negative camber with 4 passengers in the car, giving 8" total deflection at the rear. The English springs now have 2-1/2" initial camber and are measured and run with 1/2" negative camber, giving 6" deflection at the rear under the same condition. However, our comparison of riding of the same car with 6" to 8-1/2" deflection on the rear springs (obtained with the same load by changing the springs) shows that even such a large change in the deflection at the rear does not account for the observed differences in riding quality. (Although the improvement with increased rear spring deflection was noticeable.) II. Summary of work on 12-MC We suggest that the possibility of springs being incorrect for load does not fully account for the riding quality. On 12-MC as received the springs were certainly correct for the load, or slightly on the soft side in front. With four passengers the camber at the front was .900 negative and at the rear 1/2" negative. The following is a summary of the changes which we found made an improvement: (8" deflection at rear) a.{Mr Adams} Changing the rear springs to give 1" negative camber/gave a slight improvement only. b. Fitting new front springs specially made up to give a stiffness of 340 lbs. per inch at 1/2" negative camber when clamped to the wide axle pad (corresponding to 2-1/2" initial deflection) gave an improvement. (Original springs had a stiffness of about 380-390 lbs. per inch when clamped to wide pad.) c. With these same front springs, the front horn was then pushed forward in the frame to make the shackle vertical. The riding was found to be further improved. | ||