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).
Suggested gear ratios for the Bensport gearbox.
| Identifier | ExFiles\Box 86\4\ scan0040 | |
| Date | 25th January 1933 | |
| HS.{Lord Ernest Hives - Chair} } FROM HDY.{William Hardy} BY.{R.W. Bailey - Chief Engineer} } X 228. C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} HDY{William Hardy}1/M25.1.33. BENSPORT GEAR RATIOS. If the gearbox ratios recently sent for the 20/25 box on the Bensport are considered to be what is wanted, we suggest that similar ratios should be obtained on the Bensport box by making the constant mesh gears 31/40 instead of 30/41. The ratios then become .8, .55, and .35. The larger pinion will pass through the bearing housing without any special dimensions. The first speed of .35 with a 4.1/1 axle, 110 BMEP., and 36 cwt. weight of car (four persons in car) should enable the car to climb a 1 in 3 gradient without reduction of speed, but possibly not restart on such a gradient. As we cannot easily reduce the 1st. speed ratio on the Bensport box without also reducing the 3rd speed, we think that an early opportunity should be taken of determining whether the .35 ratio is low enough for competition work of the freak hill variety, such as on the recent London - Exeter trial. HDY.{William Hardy} | ||