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).
The testing of Dunlop high-pressure tyres, discussing mileage, pressures, and effects on steering for the Phantom and 20 HP models.
| Identifier | ExFiles\Box 29\1\ Scan151 | |
| Date | 31th October 1925 | |
| R.R. 493A (50 H) (D.D. 31. 12-6-25) J.H.D. EXPERIMENTAL REPORT. Expl. No. 4457 REFis/Rm{William Robotham - Chief Engineer}2/LG31.10.25. To BJ. From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to FN. c. to CWB. TYRES. X3538 With reference to BJ2/H30.10.25 attaching copy of R4/M25.10.25. We have, up to the present, only run the new Dunlop well base wheels and wired on high pressure tyres 1,600 miles in England. They have given no trouble but this mileage on English roads does not constitute a test. They are being run during the next 10,000 miles test in France. At the moment we do not know of any other makers standard high pressure tyres which can be fitted to these wheels. With reference to the tyre pressures suggested by R.{Sir Henry Royce} From the point of view of high speed wobbles, we do not want to go below 45 lbs/sq.in. on the front axle of the Phantom. The main question on the 20 HP. is road shocks on the steering wheel. The attached copy of a report from France on a Phantom, indicates the effect which inflation pressure has on the steering. We can see no objection to the recommended pressures on the rear wheels. Hs{Lord Ernest Hives - Chair}/W.A.Robotham. | ||