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).
Comparing the rear springing of the EAC.7 model with an equivalent Phantom.
| Identifier | ExFiles\Box 16\7\ Scan021 | |
| Date | 3rd September 1927 | |
| Hs.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} from DA.{Bernard Day - Chassis Design} X7410 DAL/M3.9.27. EAC.7. REAR SPRINGING. X.7410 X.8410 With reference to the question, raised by Hs.{Lord Ernest Hives - Chair} while here, of the apparently heavy rear springs needed on EAC.7. compared with an equivalent Phantom, it is pointed out that what may be called the 'nominal' load of the springs has not the same meaning in the two cases. On the Phantom the nominal load is that after a deflection of 3", but on the actual car the springs are deflected through 4½" under 'full load'. On EAC.7. the nominal load is that after a deflection of 8.25", that is, the equivalent of the full load in the Phantom. If there were a car of each type precisely similar as to full rear load, and a 2200 lbs. spring were found satisfactory on the Phantom, it is evident that an 1100 lbs. EAC.7 spring would be too light for that car. The spring required would be 2200 X 8.25 / 6 X 2 = 1510 lbs. On EAC.7. as made however, there has been a re-distribution of weight as regards front and back, so that in spite of the 1400 lbs. springs now fitted, it is possible the car is lightly sprung compared with an equivalent-c Phantom. DA.{Bernard Day - Chassis Design} | ||