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).
Comparison of spring weights and specifications for different sedan models.
| Identifier | ExFiles\Box 43\2\ Scan086 | |
| Date | 18th December 1925 | |
| Oy4-E-121825 -3- December 18, 1925. The average of the more expensive cars over here are therefore softening their front springs a lot and using more effective (but "gentler") shock absorbers in front, with good effect on their riding qualities. 12-MC. On fitting 12-MC with a sedan body, lamps, mudguards, etc. we found that it did not ride well. It weighed with full tanks but without passengers - Front 2750 Rear 2885 Total 5635 Comparison with our sedans is as follows - Our sedans average:- Front Rear Total 2450 2950 5400 Deduct unsprung weights - 350 690 Sprung weights are 2100 2270 Add (for four passengers) 120 480 Spring loads total 2220 2750 Per spring 1110 1375 Theoretical springs (Fronts flat, Rear 8"deflection) 1110 2060 Springs used 1100 2000 (See attached list of car weights and springs.) 12-MC Front Rear Total 2750 2885 5635 Deduct unsprung weights 460 680 Sprung weights 2290 2205 Add (for four passengers) 120 480 Spring loads total 2410 2685 Per spring 1205 1342 We should use springs (Fronts flat, Rear 8"deflection) 1200 2000 This confirms your instructions that for the Phantom engine we should increase our front springs by 100 lbs. each. (Note: Our springs front and rear are still measured in the flat position. Fronts have 3 1/2" and rears 3" initial camber. We run the front springs flat and the rear springs as nearly as possible with 1" negative camber when the car has full tanks and four passengers, assumed to | ||