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).
Vehicle suspension tests focusing on spring ratings, buffer clearance, and ride comfort.
| Identifier | WestWitteringFiles\S\September1928-October1928\ Scan021 | |
| Date | 6th September 1928 guessed | |
| contd :- -5- produced by reducing the front spring rating 19%. We could not measure any improvement when running with soft tyres and no front shock absorbers. We therefore consider that it is doubtful whether it is worth springing any car with less than 3.5" buffer clearance at the rear. With 2.5" buffer clearance the car was quite impossible for normal use. We made a final test of the car arranged with 4" buffer clearance at the rear, 19% weaker front springs, no front shock absorbers and tyre pressures 35 lbs/sq.in. front - 25 lbs/sq.in. rear, all springs in a good state of lubrication. Under these conditions the standard 40/50 low speed complaint was almost entirely absent and the riding compared favourably with that of the 20 HP. car. The riding remained good up to 55 m.p.h. when pitching commenced due to the unrestrained front end. The same result occurred on a bad road at a somewhat lower speed. The Repair Dept. tried the car with us and agreed that it was a suspension which would overcome the majority of their complaints of low speed riding discomfort. Naturally the car in this condition was arranged to minimise on a particular complaint. It will be noted that the above results differ from our previous conclusions that the front end suspension affected the rear seats appreciably. In our previous series of tests of this nature, however, we had no rear hydraulics. All our present tests have been conducted with the rear hydraulics in action since we have shewn that the car rides as well in the rear seats in this condition as with no shock absorbers at all. We have therefore been working on rather a different basis. contd:- | ||