Comparison of split versus unsplit leaf springs for different driving conditions.
| Identifier | ExFiles\Box 80\2\ scan0058 | |
| Date | 1st November 1920 | |
| R.R. 235A (500 T) (S.D. 408. 26-4-17.) Bm. 2/156/13. - 2 - Bn {W.O. Bentley / Mr Barrington} 11/No..20 Contd. To R. {Sir Henry Royce} from Bn. {W.O. Bentley / Mr Barrington} of your telegram we have applied ourselves more particularly to ascertain whether unsplit leaves are better than split leaves as an all round proposition. Our opinion on this matter, based on tests carried out to date on the bumping rig and on the road, is that the split springs certainly if fitted with shock absorbers are preferable to unsplit springs certainly for town work, and more generally for all classes cases in which the car is used as a carriage, and is driven considerately and not at high speeds without thought for the condition of the roads. On the other hand the unsplit springs, we think, are better if the car is required to be driven at high speeds on bad roads and generally to meet the conditions of driving demanded by, for example, Mr. de Salamanca. We feel that we attempt more perhaps than our present knowledge enables us to accomplish when we set out to make our springs suitable for these widely different conditions, as pointed out in your note, HS {Lord Ernest Hives - Chair} /C27/1/20. The split springs appear to help us considerably as regards the throwing about sideways of the body on a bumpy road at reasonable speeds but the consequent lateral control is perhaps insufficient to deal with the violent disturbances which occur at high speeds. On the other hand the springs which are not split give us the required lateral control at high speeds but the lateral rigidity is felt quite appreciably on the body when passing over pot-holes. With regard to the effect of lateral rigidity in rear springs it must be borne in mind that a reduction in lateral rigidity also reduces those forces between the axle and the chassis which restore the axle to a parallel position relatively to | ||
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).