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).
Shock absorber testing, detailing load settings and observations on ride quality.
| Identifier | ExFiles\Box 16\7\ Scan178 | |
| Date | 14th May 1929 guessed | |
| contd :- -4- that the loads at the rear should be as high as 75 lbs. up and 150 lbs. down. We started all our tests on shock absorbers over again with the supposition that R.{Sir Henry Royce} was right and starting with his loading we altered it step by step until we got the best results. We found that at the front the best setting for all round purposes was 60 lbs. up and 60 lbs. down with five dynamic restrictions fitted. At the rear 80 lbs. down and 80 lbs. up again with five dynamic restrictions fitted. We have come to the conclusion that theory is absolutely useless in springing a car as all our pre-conceived ideas of what a shock absorber should be seem to have been knocked on the head from the practical results we have obtained. We were really quite anxious to get away from the dynamic restrictions and only came back to them because they gave us the best results. We are also quite positive that the upward and downward loading must be somewhere near equal to give the best riding. The main advantage in the dynamic restriction is that they are removed from the front and the rear we have to put up the fixed load to over 100 lbs. to get the same high speed control of the car and in consequence we do feel that the car begins to rid uncomfortably harshly at low speeds. Our indicator tests have shewn us and our own personal impressions on the road confirm, that we get a lot of cushioning due to the fact that the shock absorber arm twists an appreciable amount when load is applied to the ball end owing to the fact that the torque puts a load on the relatively flexible arm. contd :- | ||