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 unsprung weight and handling characteristics of the PI and PII rear axles.
| Identifier | ExFiles\Box 18\1\ Scan038 | |
| Date | 3rd June 1930 | |
| Pim X7840 Unsprung Weight: (Rear Axle) what surprises me is that we reckoned 680 lbs for unsprung wt. of P I. So P II apparently has 58 lbs more unsprung wt. than P I. yet it appears to hold the road better on corners, possibly due to greater lateral rigidity of rear springs. Have you any figures on the "hopping" frequency of the rear axle on P II compared with P I and do you confirm attached figure? Oy June 3/30. | ||