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).
Component failures and performance issues with shock absorbers, rear springs, and the steering box support during testing.
| Identifier | ExFiles\Box 180\M2\M2.6\ img041 | |
| Date | 22th September 1925 guessed | |
| -3- suggest that it would give us useful information, if on the next car that goes out to France for test, one front and one rear spring were by this firm, of the same strength, etc. as would have been fitted if English springs had been fitted throughout. The question of the shock absorbers affects the springing very greatly, and, as the days proceeded, I gradually tightened these up more and more, with improved results. The trouble was, however, that the amount of friction became gradually reduced during the days run, and it would be necessary in order to maintain them in a given condition, to adjust them about every 200 miles, which is not considered at all satisfactory. I was not able to determine whether the working of the shock absorbers actually slacked back the adjusting nuts or whether the result was caused by wear or other internal cause, but it is considered that once a week is the very shortest period at which it should be necessary to give any attention to a shock absorber when it has once been set to give the results required. (2) REAR SPRINGS. Both rear springs failed. I understand the mileage was between 17,000 and 18,000 in each case. The same remarks as made regarding the front springs apply to the rear springs in a lesser degree, and also, to the rear shock absorbers, more friction is required. Generally speaking, over an uneven, but not 'pot-holey' road, where the car was not bumping at all, there was too much friction motion on the springs, and it would appear quite safe to slightly reduce the clearances and to stiffen up the springs to the extent where an equal amount of energy is absorbed in the reduced deflection. (3) TUBULAR SUPPORT OF STEERING BOX. This broke at 8250 miles. It is not considered that the cause of the fracture was due to stresses occasioned from the steering mechanism, but was due to the fact that the tube forms a strut between the side of the engine and frame; in fact, as the engine is supported at two points at the rear, and on a pivoted bearing on the front, this tube must be very considerably stressed when the frame is racked in passing over rough roads, etc. | ||