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).
Misunderstandings regarding speed, engine power, tyres, and suspension improvements for cars.
| Identifier | WestWitteringFiles\O\January1926-March1926\ Scan181 | |
| Date | 31th March 1926 | |
| HS.{Lord Ernest Hives - Chair}) TO DA.{Bernard Day - Chassis Design}) FROM R.{Sir Henry Royce} BY.{R.W. Bailey - Chief Engineer}) (Le CanadelHenry Royce's French residence.) C. to CJ. BJ. WOR.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} RG.{Mr Rowledge} PN.{Mr Northey} OY. NA.{Mr Nadin} CWB. ORIGINAL R1/M31.3.26. Delivered to WW. during the Easter holiday. X8410 X5520 X8820 X235 X9430 X5410 SUSPENSION & TYRES OF RR. CARS. My last memo. produced some misunderstanding which I should like to correct. (1) Regarding possible speeds and engine power, naturally I did not wish to reduce these, because we are working to get more power, but I meant that personally I would rather avoid high road speeds rather than be deprived of lower pressure tyres. (2) Regarding standardisation of lower pressure tyres I wished this to be done (as I understood test agreed) as soon as more effective shock dampers could be fitted, on the understanding that our hydraulic ones were within sight, and unless we anticipate events they take such a very long time before customers are receiving them. I meant by this to reduce our stock of , and orders for, the parts to be superseded. (3) Regarding road springs I believe these are nearly as good as we can make them in the weight and space at our disposal, that we shall probably do more harm than good if we altered them, except perhaps a few per cents, and that the recent complaints are not due to any change in the stiffness of the road springs, either front or back, if to our standard, but are new conditions of either roads, tyres, or relative weight between the front and the back, or shock dampers. (4) Here in this part of France the roads are dreadfully irregular, with very many bad potholes. To save the passengers, car body, steering, and chassis generally, demands tyres at lower pressure, and very effective shock dampers. It is impossible to notice the defect complained of owing to this extremely rough condition. (5) The demonstration at Derby shews that shock dampers, at least of the solid friction type, increase this trouble, and if the suggestion I made of altering the centre of gravity has no effect, or Mr. Day's suggestion of altering the position of the masses, then one can only think an improvement can be made by - (a) One way only hydraulic shock dampers might not be harmful. (b) A certain amount of high rated frictionless springing such as can be obtained by an undamped helical spring in series with the ordinary spring. (c) Such shock dampers as we tried to fit to the 20HP. i.e. progressively increasing small movement with no damping, and larger movement with increased effect. (1) | ||