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).
Safe loads for various tyre sizes according to the Dunlop chart.
| Identifier | ExFiles\Box 157\2\ scan0339 | |
| Date | 30th December 1938 | |
| 1332 To LA.{L. A. Archer} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}1/MH.{M. Huckerby}30.12.38. TYRE SIZES. Re your enquiry about the safe loads of various tyres, according to the Dunlop chart these are:- Wr. and 'M' 6.50 x 17 Load per wheel 15 cwt. P.III 7.00 x 18 " " " 17 cwt. (18 cwt, 5" rim) B.V. 6.50 x 16 " " " 11 1/4 cwt. B.II. 5.50 x 18 " " " 11 cwt. These are greatly in excess of what is recommended in America. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} | ||