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).
Letter to G.W. Hancock discussing clutch pedal pressure, gear noise, and other issues on a 25 HP car.
| Identifier | ExFiles\Box 5a\3\ 03-page106 | |
| Date | 6th November 1931 | |
| G.W.Hancock from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Hotel de France, Chateauroux, Indre, France. X5840 Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}1/AEH 6.11.31. X5840 25 HP. CLUTCH. We have been very concerned about the increase in pedal pressure on 18-GIV with the stronger clutch springs which were fitted before the car left for France. The average pressure required to start the 40/50 clutch moving is 34 lbs. The figure you give us for the 25 HP. as 53 lbs. The 40/50 finishes at about 47 lbs, 18-GIV at 66 lbs. In London traffic we consider that such a pedal pressure would be intolerable for a lady. For this reason we have been going over the spring loads and the results show that we ought not to require clutch springs any stronger than those that were fitted to 19-GIV on its last 10,000 mile test. If we fit these clutch springs we have proportionally the same load to take the drive as on the 40/50 which never gave us any trouble. You will appreciate yourself that 19-GIV clutch probably slipped mainly because it was oily. We have therefore sent out to you a set of clutch springs to G.54132 which we should like you to use during the remainder of the 10,000 mile test or until you are troubled with clutch slip. The actual increase in torque on the car you are running is very little compared with 19-GIV and we shall therefore be very surprised if you do get clutch slip. We note that you have begun mileage. We think that it is rather misleading to say that none of the gears are good enough for production, because we think you will agree that the 3rd. speed on your car under load is quieter than what the Works are turning out on production at present, and it is only the side shaft gear noise which is below our present quality. We note your remarks re springing and shall be glad to have the exact front buffer clearance so that we can compare the results with those on 19-GIV. 18-GIV is, of course, a heavier car than 19-GIV. We are concerned about the engine gear rattles and are doing all we can to eliminate them at this end. | ||