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).
Back axle ratio for the Phantom, advocating for the 14 tooth axle.
| Identifier | ExFiles\Box 49\2\ Scan208 | |
| Date | 10th June 1926 | |
| To HS.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} Copy to -BJ. " -Wor.{Arthur Wormald - General Works Manager} " - BY.{R.W. Bailey - Chief Engineer} X4299 R8/M10.6.26. PHANTOM BACK AXLE RATIO X.8310 - X.8350. With reference to the Phantom back axle ratio, rather strangely the car I had in the south of France was fitted with smaller wheels - smaller tyres on 21" wheels - and they were just equivalent to one tooth off the 15 tooth axle. Also Mr. Nadin says that in America the driving is done by avoiding changing to the 3rd speed - i.e. most of the traffic work is done on the top gear, and no speeds beyond 60 MPH are used. HS.{Lord Ernest Hives - Chair} also thinks it is very rare for people to demand more than 60 MPH. Under the most recent impressions of comparing various cars I have come to the conclusion that we must be able to supply 14 tooth axles, especially for the heavy bodies. I have also learned that the 14 tooth axles were much more generally used than any other type on the Silver Ghost cars. We cannot therefore say that 14 tooth axles are too difficult to get quiet, and from my own personal experience I do not think our Phantom engine will prove too fussy at the necessary speeds that this back axle will demand. I think therefore we must go on with the 14 tooth axles and have then availablefor the American trade, and for heavy cars in our own English trade, because ubdoubtedly the acceleration, power of engine, and performance on top gear, are all definitely improvedd with this gear ratio overthe 15/52. R.{Sir Henry Royce} | ||