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).
Damping and vibration tests, including load readings and observations on ride quality.
| Identifier | ExFiles\Box 101\2\ scan0173 | |
| Date | 14th November 1936 guessed | |
| ( 3 ) disconnected. This merely produced violent vibrations through the frame and made the steering column uncomfortable to hold. Harder damping at the front slightly reduced this tendency, but was not sufficient improvement to permit the permanent removal of the tie-bars. It appears that these are essential as long as the present frame construction is adhered to. Having ascertained our required damping, we removed all dampers, and accordingly set them in conjunction with the control system load. We enclose a rough sketch of our rig. The maximum loads were set by adjusting the thickness of the washer under the mushroom valves of which we have a varied stock. The actual readings are as follows :- Full load on bellows i.e. 23 lbs. Period of oscillation 14 seconds (This was found to be a convenient time as we have no 4 ft. extension available, in which case we assume the time would have been 2 seconds with a corresponding increase in effective poundage). Front Dampers 80 lbs. Rear Dampers 100 lbs. This should be an intelligent result for you to work on, but if required we can give you the figures using the 4 ft. extension, but it would mean completely dismantling all the dampers to block up the piston leak grooves, and then again, to unblock them after the readings had been taken. The minimum initial load for low speed ride was maintained the same, by inserting the original aluminium washers behind the end caps, but with all .015" washers removed. The actual reading in this case was 40 lbs over a 2 second oscillation. In conclusion we would point out that the ride we have obtained, although in advance in quality on anything that has been previously experienced on this car, is not yet 100%, there still being a soft up and down movement in the back seat over ordinary roads which however, is lessened when going over a rough road, showing the periodicity is destroyed. Perhaps different rating rear springs would eliminate this. There is also the unpleasant frame vibration which, although not so noticeable since the tie-bars were fitted, still prevails. ------------ GWH{George W. Hancock - Head Chateauroux}/HFH.{Hoppy F. Hamilton} H.{Arthur M. Hanbury - Head Complaints} Hamilton. | ||