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).
Replacement of thick leaf springs with thin leaf springs, considering cost and performance.
| Identifier | WestWitteringFiles\I\October1922\ Scan66 | |
| Date | 26th October 1922 | |
| R- THE TIME HAS COME TO DITCH THE THICK- 40/50 FRONT SPRINGS ORIGINAL LEAVED R-R POLICY RECEIVED OCT 30 TO - H.R. H.S. FROM R.{Sir Henry Royce} R1/W/26.10.22. 40/50. LEAF SPRINGS. X2628 Referring to W17/M201022, this seems to be a question of money. The 235 springs we understand will all be wanted and that the cost of these is approximately £6 each, assuming also that the cost to replace them with thin leaf springs will also be £6 each, so that it is £12 per car. Originally the thick leaf spring was introduced because of the complaints: (1) Weight of the chassis. (2) Friction of the twin leaf springs needed lubrication. (3) Cost of production. These springs were intended to be fitted with either single acting or progressive type of shock absorber. After running these springs for some time no serious complaints against their use were forthcoming. Personally however I found the cars were insufficiently stable at high speeds on the undulating roads on the Fens. Then renewed my demand for shock dampers. Through a certain amount of half-heartedness these shock dampers were never fitted. After many cars had been constructed with these thick leaf springs it was found in conjunction with the cord tyres that much more damping was needed and since we had not obtained this damping satisfactorily with shock dampers, and cars with thin leaf springs were found to be superior, I suggested that I should prefer to change the springs to thin leaf springs rather than fit shock dampers. The reason for my preference was that the shock dampers in their joints were much less satisfactory than the thin leaf springs, which had no serious disadvantage over the thick leaf springs. I cannot agree for one moment that the thick leaf spring with a double acting Hartford shock absorber is better than the thin leaf spring with the same fitting, or better than the thin leaf spring alone, and I am sure that the conclusions arrived at that this is the best springing in the world is not necessarily correct. Personally I would rather have thin leaf springs with lighter shock dampers, and these latter of the single acting or progressive type. The conclusion is then to my mind that it is merely a question of money. Ought we to consider the £12 seriously, considering the price the complete car is costing the customer. Ought we not to fit that which we think will give the greatest satisfaction, especially as at the moment we must do all that it is humanly possible to do, to give satisfaction. Regarding the defects of the thick leaf springs they are reported:- (1) To squeak. (2) Non-damping. (3) Break. (1) | ||