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).
Explaining the difference in stress range and life between front and rear road springs.
| Identifier | ExFiles\Box 16\7\ Scan133 | |
| Date | 1st January 1929 | |
| X.7410 Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} from Day DA{Bernard Day - Chassis Design}4/MS.1.29. ROAD SPRINGS. Since speaking to you on the subject of the difference in the life of front and rear road springs on the bump, it has occurred to me that the explanation is really quite simple. Though the max. stress in each case is the same, the rating of the front is more than twice that of the rear, and since there is a constant bump of say 2" in both cases (not producing max. stress), the front obviously suffer a much greater stress range than the rear. The total range of the rear springs for instance is 13.25", and the front 5.85" for the same stress, so that 2" means a lot more to the front than the rear. The only thing to do it seems is to keep on dropping the stress in the front springs. We have already effected great improvements with this. DA.{Bernard Day - Chassis Design} | ||