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).
Bump test rig experiments on rear springs in response to steering complaints.
| Identifier | ExFiles\Box 20\2\ Scan058 | |
| Date | 31th January 1920 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to Bn.{W.O. Bentley / Mr Barrington} c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to EP.{G. Eric Platford - Chief Quality Engineer} X.963 Hsl/LG31.1.20. X.2628. X.1985. 1295 X.963. - RE COMPLAINTS OF STEERING ON CARS. We find we are able to carry out some interesting experiments on the bump test rig as regards the effect of a split leaf on the rear springs. Comparative tests taken on the road we have found are always most difficult to judge. We are running on the bump test the back part of a standard chassis fitted with a complete standard axle and with the new type rear shock absorbers. The chassis is loaded to give the normal camber spring. We are using 2" bumps fitted 180° from each other; the drums revolve at 105 R.P.M. With this standard arrangement, the back axle bounced excessively. After we had been running for a short time we measured the side movement of the bottom leaf relative to the second leaf. This movement is plainly shown on the bottom leaf of the spring by the marking which is caused by rubbing the end of the second leaf. We found the movement was .25" each side of the centre - .50" total movement. We have examined a number of cars that have been run on the road and find that .50" movement is the maximum we can find on the road on any cars so far. After the bump test had been running a short time the clip at the rear of the spring which clips the leaves Contd. | ||