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).
Effect of different tyre and wheel sizes on a 20 HP car.
| Identifier | ExFiles\Box 159\1\ scan0159 | |
| Date | 6th May 1927 guessed | |
| contd :- -2- small wheels are to be used on the Continent. The effective rolling diameter of the high pressure tyres previously used on the 20 HP. car (32 X 4½) was 31.4". The rolling dia. of the 5¼" tyre which caused the swan neck to be bent and the tank drain plug to be damaged on the recent run to Le CanadelHenry Royce's French residence was 30.7". We hope to have a set of wheels and tyres on test with 19" rims in about three weeks time. Hs{Lord Ernest Hives - Chair}/W.A.Robotham. | ||