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).
Notes and recommendations on car springing, including rear and front spring weights and damper settings.
| Identifier | ExFiles\Box 16\7\ Scan283 | |
| Date | 4th July 1930 guessed | |
| SPRINGING OF R.R. CARS As a result of fair experience with Springing Complaints on R.R. Cars of all categories, I think I am in a position to make a few notes which might prove of value to those who are, or may be, called upon to improve the riding qualities of our cars on the Continent. They are the more valuable because I have tried to find out the customer's likes and dislikes, and as far as possible carry out tests with them. Assuming that certain essential requirements, such as tyre pressures, well lubricated leaves, load distribution etc, are recognised and respected, the following points may be found to be of use :- (A) Rear Springs Weights and damper settings. Rear springs should be strong enough to avoid crashing on the buffers when the car is driven fully loaded, and Shock dampers detached, at a fair speed over moderately bad pot holes or a single cross road gully (caniveau). They should not be strong enough to avoid crashing in negotiating a double caniveau under similar conditions. I find this test practical and useful in defining correct weights of springs which will withstand full load touring with comfort at high speeds and equally so at slow speeds over cobbles. When springs answering these requirements are fitted, the Hydraulic Shock Absorbers at the rear should be adjusted to suit the service of the owner, viz; low pressures and no holes in H.P. valves for people who use moderate speeds on all occasions, higher ratings up and down in proportion to increased road speeds, or special local conditions, until the maximum up and down pressures are reached when anything above 80 lbs should be accompanied by one or possibly two .030" holes in the H.P. valve as recommended by Works. The latter is in my opinion essential to give relief when lower speeds are imposed. At this point, I believe one can definitely leave the rear springs and shock dampers and forget about them as far as considering they play any further role in the riding qualities of the car. Front springs and damper settings. I believe front springs and dampers require more attention than is generally assumed or bestowed upon them. I suggest that for good riding, the springs should be no stronger than is necessary to prevent crashing or to put them outside the range which interferes with the steering qualities of the car. The rest should be done by damping. | ||