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).
Dynamics of car riding and the three ways a car can oscillate: rear, front, and pitching.
| Identifier | ExFiles\Box 28\5\ Scan048 | |
| Date | 1st June 1930 | |
| X457. Hs.{Lord Ernest Hives - Chair} Da.{Bernard Day - Chassis Design} } EP.{G. Eric Platford - Chief Quality Engineer} } FROM R.{Sir Henry Royce} C. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} C. PN.{Mr Northey} Hm.{Capt. W. Hallam - Head Repairs} R2/112.6.30. Y457 CAR RIDING. We now all agree that there are 3 ways a car can oscillate:- (a) the rear. (b) the front. (c) the pitching. each having its own period and acting upon the passengers differently. Heretofore we have hardly realised the importance of the pitching - (c) - which is considerably faster than (a) or (b). It struck me on our journey to London on Thursday that the pitch speed corresponds with the average road speed, so that passing an imperfection in the road the effect on the car built up from the effect on the front axle is increased by the effect from the back axle. There seems no way of avoiding this at some speeds but the lower the speed, and the less vigorous, the better. Modern roads being generally very smooth, with occasional single defects makes this phenomenon more noticeable than a road with a more generally bad surface such as found around Le CanadelHenry Royce's French residence. I do not think for a moment that shortening the wheelbase would be good. Undoubtedly the most effective way is to reduce the rating of the front springs, the speed of pitching is reduced and the energy of pitching also. I do not believe we must render the shock dampers less effective, and apparently the rear ones should have high recoil pressure. Weight distribution is again the most of all important. We must keep the middle of the car light. R.{Sir Henry Royce} | ||