Tyre noise and tyre recommendations for the Phantom III and 20/25 HP models.
| Identifier | ExFiles\Box 157\1\ scan0294 | |
| Date | 8th April 1936 | |
| To R. {Sir Henry Royce} c. to SG. {Arthur F. Sidgreaves - MD} c. to Wor. {Arthur Wormald - General Works Manager} c. to By. {R.W. Bailey - Chief Engineer} c. to CX. {Major Len W. Cox - Advertising Manager} c. to Ex. c. to Roy. {Mr H. Royce - Buyer} X1332 Tyre Noise on the Ph.III & 20/25 HP. We recommend that the production Ph.III should be fitted with the original pattern 90 type Dunlop tyre, 7.00 x 18. Our tests in London proved conclusively that this tyre was more silent than the new Dunlop 90 type tyre with the increased buttresses on the edge of the tread. Dunlops are quite agreeable to us using this tyre, though we may not get quite so good a mileage as with their newer pattern. In order to avoid confusion, we have arranged that the Ph.III tyre shall be marked Dunlop Fort R '90', 7.00 x 18. With regard to the 20/25, Dunlops would like to see some of the 'Silent' treads that have been run on demonstration cars, together with a record of the mileage covered. These treads had 'chamfered' shoulders and were unlike any tyre that has previously been sold to the public. They are not willing to standardise these, but seem to be unable to give us an intermediate design though we have for some time been pressing the point and shall continue to do so. Hs {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer} | ||
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).