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).
Car design principles, comparing large versus small cars, and the merits of rigid frame and body construction.
| Identifier | ExFiles\Box 170\2\ img150 | |
| Date | 17th June 1933 guessed | |
| 2 even the work I have been doing here on ride comfirms this belief, and I see myself digging the grave of the large car while drawing wages for improving it. nearly As a vehicle the small car has all the advantages. Power-weight ratio. k²/ab ratio. Ratio of radius of turn to angle of front wheels. Steering ratio Resonant pitching speed. Ratio of unsprung weight. Ratio of inertia over frame stiffness. etc. But of course wind resistance is relatively much higher, and the stubbier body more difficult to propel. ✓ Am a recent convert to the rigid frame & body school. The subframe on PII was a mistake, and a heavy & costly one. the solid-mounted bodies. Chrysler. & Packard make better motor cars. My guess is that the PII x. member was just stiff enough for bad resonance, & without the assistance of a rigid body mount, not stiff enough to get past the resonance peak on the upward side. We have produced shimmy on drums running 50 mph max. speed just by loosening up the two forward body bolts. A rigid body mount is very noisy. Chrysler uses a rubberized material rather softer than brake lining which with a frame that follows the contour of the body sill gives sufficient rigidity without too much trouble. | ||