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).
Road test report on a new type of spring drive fitted to a 12-EX, detailing weight reductions and performance improvements.
| Identifier | ExFiles\Box 25\3\ Scan353 | |
| Date | 25th July 1928 | |
| X634 To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} Hs{Lord Ernest Hives - Chair}/GWH{George W. Hancock - Head Chateauroux}1/LG25.7.28. NEW TYPE SPRING DRIVE X7020 FITTED TO 12-EX. Weight of damping wheels before being reduced :- Front - unit E.77389 11 lbs. 10 ozs. Rear - unit E.77390 19 " 12 " Weight of wheels after modification :- Front 8 lbs. 0 ozs. Rear 14 " 12 " Total reduced weight 8 lbs. 10 ozs. Road Test Report. 75% improvement in picking up from 4 m.p.h. - slight snatching still remains. 100% improvement for absence of noise coming from driving springs due to choc-a-bloc when picking up. No crankshaft periods noticeable. Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} | ||