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).
Gearbox development and car performance in relation to American market demands and competitor models.
| Identifier | ExFiles\Box 19\3\ Scan262 | |
| Date | 3rd April 1930 | |
| Secret. To Sg.{Arthur F. Sidgreaves - MD} from Oy. c. Srn. J.S. APR 1930 Received [STAMP] Oyl/DM.{D. Munro}3.4.30. Gearbox and Car Performance. --------------------------- In connection with various conversations I should like to point out that the two subjects - performance and the silent, easy-change gearboxes - are closely allied, because the new American gearboxes allow cars to have a combination of very high acceleration for city traffic with a high "cruising speed" for touring. Performance. ----------- Last autumn we gave as representative American figures - 10 - 25 m.p.h. in 6 secs. 10 - 50 m.p.h. in 15 secs. Although we do not have later figures, we think it may be assumed that the new cars like the Cadillac 16, or the Chrysler models with two silent speeds, can better these figures considerably Therefore, we think it is unimportant whether P.I, P.II or the 25 h.p. have the best acceleration, since we believe none of them yet have acceleration adequate to the American demand, and we fear that sales in the States will not be as good as they might be until we catch up with this demand. Gearbox. -------- We suggest that the gearbox is of the greatest interest to Rolls-Royce because the desired smoothness of operation cannot be maintained if axle ratios are lowered to obtain increased acceleration, and engine power cannot be increased indefinitely without roughness, so that the only alternative seems to be to retain a high axle ratio with two silent gears and "fool-proof" gear changing between the two. I gather that there is one "immediate" possibility which might be developed, perhaps not for the 200 order, but soon after - namely, the present box made silent by perfection of workmanship, and fitted with a free-wheel for easy-changing. cont'd.{John DeLooze - Company Secretary} | ||