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).
Pros and cons of using freewheels on cars.
| Identifier | ExFiles\Box 6\2\ 02-page026 | |
| Date | 1st December 1927 | |
| X.523 BJ. From R.{Sir Henry Royce} c. to Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} c. to CMB. DA.{Bernard Day - Chassis Design} SQ. c. to PN.{Mr Northey} C. 32/H.12.27. FREEWHEELS ON CARS. These seem to be attracting considerable attention. Personally, I think they are a mistake. They are by no means a novelty, and have been used on and off for many years. Our own application has been a more moderate one, namely, the use of a freewheel on the side shaft of the gearbox. It was thought by most of us to be an advantage but it had the dis-advantage that the engine could not be used as a brake downhill on the gears. This disadvantage however hardly counts now that brakes are so wonderfully improved, and no-one thinks - with our cars - of getting on their gears to descend a hill. I do however like to use the engine to help lifting up instead of the brake, and to assist braking downhill, on the direct drive. So that we feel inclined to again try the freewheel in the gearbox to assist in changing the gears. Regarding the use of the freewheel in the transmission this has been supplemented by an extra lever to cancel the freewheel. As we have said above we do not think this system is altogether an advantage, but it may be of considerable advantage to the 4-cyl. people, owing to their over-running vibrations being very bad. It would have some advantage to us as it would reduce the tendency of firing in the exhaust, but the disadvantages are so considerable that unless I am mistaken we should prefer to be without it, and especially we think that under certain circumstances time will be lost, and irritation caused, by the engine having to pick up speed to mate with a rather fast moving car. We do not therefore propose to make any attempt to go the whole hog until we hear more about it. Really of course we have our hands quite full of improvements which are more to our own ideas, though less startling. R.{Sir Henry Royce} | ||