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).
Vehicle performance, axle ratios, and the advent of free-wheeling and automatic transmissions.
| Identifier | ExFiles\Box 19\4\ Scan320 | |
| Date | 25th May 1931 guessed | |
| - 5 - Secondly - On the old Silver Ghost we started in first with a 16/52 axle ratio and when we changed it down to 15/52 and later to 14/52, this same question was raised. In this case we got an improved maximum speed by reducing the axle ratio, with the result that 14/52 became standard here and in England. We had a rather amusing incident returning from our trip last week. Just after leaving Hartford for Springfield we were passed by a new Chevrolet. Caswell who was driving went after it and was not able to overtake it till we hit a piece of straight concrete (at this time the speed was around 75 m.p.h.), but the little beggar passed us again within a mile and do what he might, Caswell could not overtake him again. This model Chevrolet sells for about $550.00. On all the PII's we have tried yet we have noticed an axle whine between 25 and 30 m.p.h. which was if anything more noticeable in the finished car than in the chassis. Is this a characteristic of the job and present in each one? In getting ready to fit these with bodies a considerable number of small points have come up from time to time. These we have referred to Derby and I am glad to say in every case have been handled very satisfactorily. Please consider the above notes entirely personal. My object in writing this is to put before you as clearly and as soon as possible the various views over here that we may be ready for developments as they arise. With regard to developments, by far the biggest item this year is the advent of Free Wheeling which has been developed until it is an undoubted success. See Mr. Porter Chase's remarks as reported by Caswell. This is to such an extent that in every modern automobile something is looked for either in the easy gear change or on the lines of a free wheel. We believe this is only the beginning of a real attack on the transmission mechanism of the automobile. We have already had referred to us three different types of automatic transmissions where the whole of the operating gear is controlled from the accelerator pedal. One of these I sent you some descriptive data on a short time ago. I have another one now which is a hydraulic gear and in my opinion not so good as the electro gear. Still a third one of which I have not yet the particulars, has been worked out by General Electric Company under the direction of the late Mr. Steinmetz who, I understand, laid out personally the electrical part. I will send you along details of this when I get it. The general public now are beginning to take an interest in these automatic gears and quite frequently one runs across newspaper articles describing them. We must bear in mind that the conventional gear shift by which gears are slid in and out of mesh by hand operation is about as unmechanical a feature as can be found in any piece of mechanism, and however much it is dolled up and so called "improved" it still has the one drawback that it is making gears perform a duty they were never meant to do, | ||