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 gear ratios and advocating for the use of hypoid gears.
| Identifier | ExFiles\Box 102\4\ scan0072 | |
| Date | 28th May 1931 | |
| X5350 HS.{Lord Ernest Hives - Chair}FROM R.{Sir Henry Royce} R4/M28.5.31. C. to SG.{Arthur F. Sidgreaves - MD} NOR. C. to DA.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} BACK AXLE RATIO. X.7350. X.5350. Referring to HS{Lord Ernest Hives - Chair}7/MJ 20531., I have been slightly mistaken as I imagined the 40/50, had a 12/41 back axle as standard for 26.3 MPH. I think therefore if we had 12/41 and 13/41 available for the easy change and the 100 MPH. demonstartion car, it may be as high as we wish to go. Naturally I should much prefer that these were hypoid. With reference to the 25HP. my memory of 11 teeth was quite correct. In this case it looks as though again we ought to have available 12 teeth and 13 teeth. These too should be hypoid. We do not think that 14/41 or 14/50 will be needed until we have proved the others are too low. Actually we hope the peak HP. will be at higher revs. than at present. If these gears are made hypoid they will be more valuable - i.e. will only need doing once. R.{Sir Henry Royce} | ||