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).
Query and response regarding the approved figure for road wheel revolutions per mile for 20/25 HP tyres.
| Identifier | ExFiles\Box 50\4\ Scan313 | |
| Date | 28th October 1929 | |
| X4308. Hs {Lord Ernest Hives - Chair} /AJL. from EFC. {E. Fowler Clarke - Electrical Engineer} EFC {E. Fowler Clarke - Electrical Engineer} 1/AD28.10.29. Can you give me please the latest approved figure for the road wheel revs per mile for the present standard 20 HP. or 20/25 HP. tyres? You will remember you gave me 608.7 for the Phantom II. Answer 660. for 6" x 19" Tyres EFC. {E. Fowler Clarke - Electrical Engineer} | ||