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).
Comparison diagram of a 'Present' tyre and rim design versus a 'Pilot' tyre and rim design.
| Identifier | ExFiles\Box 146\1\ scan0072 | |
| Date | 2nd November 1937 guessed | |
| 1. Present tyre. 2. Thick rim. 3. Plain or open rim. 4. "Pilot" tyre with very wide base. 5. Thin and very wide rim. 6. Crosswork of thin blades forming spokes. | ||