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).
Assumptions on tire deflection and its effect on oscillation frequencies and riding quality, with a comparison to the Lancia Lambda.
| Identifier | ExFiles\Box 43\2\ Scan218 | |
| Date | 25th August 1927 | |
| Oy9-E-82327 -3- August 25, 1927. The particular example of this is the Lancia Lambda, which has 9" deflection of the front springs, compared with our 5-3/4", and stiffer shock absorber action than we have attempted. Tire deflection. Our assumptions, based on the work of other experimenters, have been to add the tire deflection to the spring deflection when calculating oscillation frequencies. We have assumed 1" deflection for 6-3/4" tires and 5/8" deflection for 5" tires. This is necessary in order to avoid the very complicated results which occur when the movement of the axle between road spring and tire is taken into consideration. We know such effects do occur (for example the criss-cross vibration of the front axle, at 550 - 600 per minute) but they do not appear to affect seriously the two basic movements of bouncing and pitching, from which the passengers get their impression of riding quality. Oy. MO/E | ||