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).
Calculations and analysis of vehicle roll rates and suspension, with a comparison of competitor vehicle suspension deflection.
| Identifier | ExFiles\Box 110\3\ scan0004 | |
| Date | 31th July 1940 | |
| - 2 - Cont'd.{John DeLooze - Company Secretary} Tyre roll rate (tyre rate 1000 lb/ins) = 2000 lb. ft/deg. Overall rear roll rate = 141 lb.ft/deg. Total Roll Rate = 279 lb.ft/deg. Rolling weight = 2540 lbs. Roll rate per 2000 lbs of rolling weight = 220 lb. ft/deg. This figure should be about 340 lb. ft/deg. If it were, the total roll rate would be 431 lb.ft/deg. Suppose, in order to save a rear roll rod, the difference of 152 lb. ft/deg . is added to the front wheels. The distribution of roll couple will be - front, 67.3% - rear, 32.7%. 67.3% is rather a lot to put on the front wheels and so a rear roll rod becomes desirable. Hardening up the suspension is another way of rendering a rear roll rod unnecessary. Other small cars have relatively hard suspensions, as the following small list shows :- CAR. VIRTUAL DEFLECTION OF SUSPENSION WITH 4 PASSENGER LOAD. Front. Rear. Austin 10. 1.6" 4.4" Morris 10. 4.4" 4.6" Vauxhall 10. 4.5" 4.6" Standard 8. 3.4" 3.6" Rm{William Robotham - Chief Engineer}/GB. | ||