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).
Summary of suspension tests conducted at 30 M.P.H. over a hump back bridge on a Spectre model.
| Identifier | ExFiles\Box 95\3\ scan0063 | |
| Date | 18th February 1937 | |
| SUMMARY OF SUSPENSION TESTS AT 30 M.P.H. OVER A HUMP BACK BRIDGE. TABLE DATA: TEST NO 1. CAR: SPECTRECodename for Phantom III SPRING INITIAL DEFLECTION: FRONT 7", REAR 7" BUFFER CLEARANCES: FRONT BUMP 3", FRONT REBOUND 2", REAR BUMP 4" WHEEL-BASE: 142" ALTERATIONS FROM STANDARD: - DEGREE OF DISCOMFORT COMPARED TO SPECTRECodename for Phantom III: 95% WHETHER FRONT WHEELS LEAVE THE GROUND: YES OTHER NOTICEABLE FEATURES UNDER NORMAL ROAD CONDITIONS: TENDENCY FOR PITCHING INCREASED SLIGHTLY - SHOCK DAMPING INSUFFICIENT - STEERING- POSSIBLY IMPROVED FOR CONTROLLABILITY AND ROAD SHOCKS - REAR AXLE DITHER IMPROVED. TEST NO 2. CAR: (SPECTRECodename for Phantom III) ALTERATIONS FROM STANDARD: FRONT SHOCK DAMPER LOADS 450 LBS. DEGREE OF DISCOMFORT COMPARED TO SPECTRECodename for Phantom III: 80% WHETHER FRONT WHEELS LEAVE THE GROUND: YES OTHER NOTICEABLE FEATURES UNDER NORMAL ROAD CONDITIONS: RIDING OF THE FRONT OF THE CAR IMPOSSIBLY HARD. TEST NO 3. CAR: (SPECTRECodename for Phantom III) ALTERATIONS FROM STANDARD: REAR SHOCK DAMPER LOADS 400 LBS. DEGREE OF DISCOMFORT COMPARED TO SPECTRECodename for Phantom III: 80% WHETHER FRONT WHEELS LEAVE THE GROUND: YES OTHER NOTICEABLE FEATURES UNDER NORMAL ROAD CONDITIONS: REAR SEAT RIDING IMPOSSIBLY HARD. TEST NO 4. CAR: (SPECTRECodename for Phantom III) ALTERATIONS FROM STANDARD: FRONT SHOCK DAMPER LOADS 450 LBS. REAR SHOCK DAMPER LOADS 400 LBS. DEGREE OF DISCOMFORT COMPARED TO SPECTRECodename for Phantom III: 70% WHETHER FRONT WHEELS LEAVE THE GROUND: YES OTHER NOTICEABLE FEATURES UNDER NORMAL ROAD CONDITIONS: RIDING IMPOSSIBLY HARD. TEST NO 5. CAR: (SPECTRECodename for Phantom III) SPRING INITIAL DEFLECTION: FRONT 10" DEGREE OF DISCOMFORT COMPARED TO SPECTRECodename for Phantom III: 100% WHETHER FRONT WHEELS LEAVE THE GROUND: YES OTHER NOTICEABLE FEATURES UNDER NORMAL ROAD CONDITIONS: TENDENCY FOR PITCHING IS REDUCED REAR SEAT RIDE MIGHT BE CONSIDERED TOO HARD FOR A LOW SPEED TOWN CARRIAGE. TEST NO 6. CAR: (SPECTRECodename for Phantom III) BUFFER CLEARANCES: REAR BUMP 3" DEGREE OF DISCOMFORT COMPARED TO SPECTRECodename for Phantom III: 105% WHETHER FRONT WHEELS LEAVE THE GROUND: YES OTHER NOTICEABLE FEATURES UNDER NORMAL ROAD CONDITIONS: NORMAL RIDING GREATLY INFERIOR. TEST NO 7. CAR: (SPECTRECodename for Phantom III) ALTERATIONS FROM STANDARD: 100 LBS WTS FIXED AS UNSPRUNG. WT TO EACH FRONT WHEEL. DEGREE OF DISCOMFORT COMPARED TO SPECTRECodename for Phantom III: 90% WHETHER FRONT WHEELS LEAVE THE GROUND: YES OTHER NOTICEABLE FEATURES UNDER NORMAL ROAD CONDITIONS: GREATER TENDENCY FOR WHEELS TO LEAVE THE GROUND. THE IMPROVEMENT ON THE BUMP IS DUE TO THE FACT THAT THE FRONT WHEELS REACH THE BUMP BUFFERS AFTER THE REAR HAVE FINISHED THEIR FULL REBOUND. TEST NO 8. CAR: (SPECTRECodename for Phantom III) ALTERATIONS FROM STANDARD: SITTING ON THE FORWARD OCCASIONAL REAR SEATS. DEGREE OF DISCOMFORT COMPARED TO SPECTRECodename for Phantom III: 40% WHETHER FRONT WHEELS LEAVE THE GROUND: YES STAMP: ROLLS-ROYCE, LTD. PRINT ROOM 18 FEB 1937 DERBY | ||