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).
Adjustments to tire pressure and suspension components to improve ride quality.
| Identifier | ExFiles\Box 28\1\ Scan128 | |
| Date | 17th July 1928 guessed | |
| - 3 - (8) At the same time we are trying to use 35 lbs/in2 tire pressure front and rear. We are not satisfied with 40 lbs/in2 tire pressure in front, because of the harsh action of the car at low speeds. Have not sent a copy of this to HS{Lord Ernest Hives - Chair}/RM.{William Robotham - Chief Engineer} as I believe you will want to discuss it with them. Obviously Rm.{William Robotham - Chief Engineer} and we are after the same thing, he with "pressure-velocity" instruments, and we with increased poundage and a leaking H.P. valve. Namely to reduce the loading for low piston speeds and increase it for the higher piston speeds. We went to the extreme when we tried solid needle valves, and these, like the Houdaille, are no good because the rise of pressure with speed is too great and the axles pull the car to bits on broken road surfaces. The leaking valve gives that feeling of free spring action in front when the car is bounced by hand on the front bumper, which we know is a sign of good soft riding at low speeds. Probably the ideal would be a moderate velocity-baffle effect such as Rm.{William Robotham - Chief Engineer} has evolved, plus valves of moderate spring load, designed to avoid "popping" and with some measured leakage-effect as well. OY. Maurice Olley r/ | ||