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).
Steering tests conducted at Brooklands with different tyre types and pressures.
| Identifier | ExFiles\Box 45\2\ Scan267 | |
| Date | 4th June 1930 | |
| BROOKLANDS. STEERING TESTS. 4.6.30. Tests were carried out with Standard Dunlop silent tyres. U.S.A. 7 x 19 Royal, and 7 x 20 ¾" off set special. U.S.A. 7 x 19 at 40 lbs. pressure. Steering slightly more positive than with Dunlop silent tyres at high speed, but bad for joggles, (about same in intensity as Dunlop at 35 lbs.) At 35 lbs - Steering heavier and joggles worse. " 30 lbs. - Steering unsteady at wobbling point both at high and low speeds, very bad for joggles, impossible over rough road conditions. --- 7 x 20 ¾" off set special wheels. 40 lbs. - Steering has about the same degree of selectivity as U.S.A. very steady at speed and joggles compare about the same as standard 7 x 20 tyres at 35 lbs. At 35 lbs. - A slight improvement on tyres at 40 lbs. pressure, steady and positive, very selective (an excellent combination.) At 30 lbs. - Joggles slightly worse but not so bad as U.S.A. tyres at same pressure. Radiator steady at all speeds. --- | ||