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).
Underframe suspension, scuttle isolation, and shock absorbers for 20HP and 40/50 models.
| Identifier | WestWitteringFiles\L\July1924-September1924\ Scan111 | |
| Date | 10th July 1924 | |
| TO R.{Sir Henry Royce} FROM DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} DA{Bernard Day - Chassis Design}/EV{Ivan Evernden - coachwork}4/104. 7. 24. Copy to - CU. IHS. BY.{R.W. Bailey - Chief Engineer} HS.{Lord Ernest Hives - Chair} Mr re. VISIT TO SALES ON 10th INST. (1) 20.HP. UNDERFRAME BODY SUSPENSION. LANDAULET GF.68. X3730 X181 EV.{Ivan Evernden - coachwork} went out in this car after having ridden in one of Barker's best examples of a closed 20.HP. R-R.{Sir Henry Royce} The difference between these two cars was very marked. The underframe suspension seemed to entirely prevent any of the high speed chassis vibrations from reaching the body, which at all speeds was perfectly quiet, and free from any suspicion of booming. By resting one foot on the chassis frame and the other on the body it was possible to appreciate how the forward rubber suspension isolated the body from engine and transmission vibrations. We are working to perfect the details of this scheme, and on their completion the car will be handed over to HS.{Lord Ernest Hives - Chair} to be thoroughly tested, and EV.{Ivan Evernden - coachwork} hopes to find an opportunity shortly to shew the car to R.{Sir Henry Royce} One is inclined to believe that the underframe suspension as used by Daimlers has enabled them to build a town carriage which has given considerable satisfaction on what must be a rougher chassis than ours. (2) 20.HP. SCUTTLE ISOLATION. X4613 It would appear that now we virtually isolate the scuttle from the dashboard, it is wrong to attach the instrument board to the dashboard and to the scuttle. We therefore feel inclined to suggest that on 'B' type cars the instrument board brackets should not be used, but the instrument board should be attached to the scuttle. On 'D' type cars where we need the off side instrument board bracket as a support for the steering column, this bracket only should be fitted, and the instrument board should not be attached to it, but supported entirely from the scuttle. We can demonstrate that when the instrument board is attached to these brackets and to the scuttle, when driving over rough roads they force the dashboard to hammer against the end of the bonnet and cause rattles. We have tried the above suggestion on several cars and met with success. We would like Mr. Royce's views, and suggest that a self supporting 'D' type column would be an advantage when we could provide the same. (3) 40/50. SHOCK ABSORBERS. X3461 Even with the body cut away to clear the horizontal shock absorbers as suggested by BY.{R.W. Bailey - Chief Engineer}, these fittings will foul the rear wing stay which of necessity has to spring from under the wheel arch, and it is very difficult for the coachbuilder to miss the shock absorber. We have shewn on N.scheme 1819. a means of overcoming this in future cars, but we suggest that if the top bracket for the shock absorber could be moved towards the rear and 3" immediately, it would cause very much less rise in the round barrel of the shock (1) | ||