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).
Advantages of smaller wheels and comparing wheel sizes for the 18-EX and 20 HP models.
| Identifier | ExFiles\Box 17\7\ Scan024 | |
| Date | 2nd February 1929 | |
| Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to SG.{Arthur F. Sidgreaves - MD} DA.{Bernard Day - Chassis Design} c. to E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} 47810 R7/M23. 2. 29. SS.{S. Smith} WHEELS. X. 7810 X. 5810 X. 3725 18-EX. There is a definite advantage in lower appearance and lower gear. 20 HP. YOU will remember the struggle I had with the Dunlops said the smaller wheels would so reduce the life. Our 20 HP. wheels were much too large when compared with the 40/50. R.{Sir Henry Royce} | ||