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).
Performance data sheet comparing 33 inch solid tyres with standard S.S. tyres.
| Identifier | ExFiles\Box 53\2\ Scan298 | |
| Date | 30th November 1926 | |
| X4565 30.11.26 X4565 RL1050 33" Solid Tyres. Tach) Revs. | R.P.M. | Lbs. | Equiv: HP. | Gear. 126 | 1500 | 142 | 64.2 | Top 1460 | 1750 | 134 | 70.0 | " 1680 | closed 2000 | 120 | 72.0 | " | open 2000 | | | " 1260 | 2250 | 159 | 71.5 | 3rd. 1400 | 2500 | 135 | 67.5 | " 1560 | 2750 | 97 | 54.0 | " Solid tyres about 3 road wheel HP. better than standard. 33 X 5" S.S. Pressure 45 lbs/sq.in. 1240 | 1500 | 140 | 62.1 | Top. 1440 | 1750 | 129 | 66.5 | " 1680 | closed 2000 | 115 | 69.0 | " | open 2000 | | | " 120 | 2250 | 160 | 69.5 | 3rd. 1400 | 2500 | 133 | 66.5 | " 1540 | 2750 | 100 | 55 | " contd :- | ||