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).
Continued page describing the characteristics and performance of a variable-rated suspension system.
| Identifier | ExFiles\Box 67a\1\ scan0184 | |
| Date | 29th April 1926 guessed | |
| contd :- -3- Positive deflections - i.e., upward road wheel deflect- ion - up to 2.55" from the mean position, take place under the action of a comparatively low rated spring of 88.5 lbs/in. Deflections over this value take place under the combined action of two springs which together give an equivalent rating of 1158. lbs/in. up to the maximum deflection of 3.130". Negative deflection, or revound, from the mean position to .935" still operates under the action of the 85.5 lbs/in. spring, while deflection greater than this from 1.10" up to the maximum of 1.30" is resisted by another spring the resultant rating being now 3200 lbs. per in. The nett result of the 'variable rated' suspension being that for normal riding over fairly smooth surfaces, where the resulting spring oscillations are small, the springing is effect- ed{J. L. Edwards} by a very flexible suspension or what is equivalent in a sumax conventional system to a leaf spring having a large free camber. The periodicity works out at 65 oscillations per min. for small amplitude. For large amplitude up to 3.130" the rating rapidly increases. For a short distance only - 1.125 - is rebound assisted by the spring and not 7.8" as would be the case if a simple leaf spring of the same rating were employed. After this rebound is opposed by a high rated spring giving a resistance, or check, to the wheel of 670 lbs. if at its maximum travel. For the above statements no account has been taken of the hydraulic damping to which the spring is subjected and which would modify the results. contd :- | ||