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).
Choice between Dubonnet and wishbone suspension systems for future models.
| Identifier | ExFiles\Box 87\4\ scan0093 | |
| Date | 18th November 1935 | |
| X 46 To Sg.{Arthur F. Sidgreaves - MD} and Wor.{Arthur Wormald - General Works Manager} from E.{Mr Elliott - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} RHC.{R. H. Coverley - Production Engineer} Da.{Bernard Day - Chassis Design} E/Tsn. E.1/HP.18.11.35. re Suspension. We have this morning received the following telegram from Da{Bernard Day - Chassis Design}:- "Olley says Dubonnet inferior to wishbone on all points due to flexibility of anchorage and arms, and costlier" - Day. The above wire rather confirms our fears with regard to the Dubonnet type suspension. We have recently made a careful review of the suspension problems in connection with Wraith, and also future Bentleys, bearing in mind the desirability of arriving at a scheme which embodies as far as possible all our experience obtained in developing the Phantom 3, the simplest and most economical arrangement of parts, the retaining as far as possible of the same principles of operation, together with the maximum of technical advantages and suitability for the chassis layout. The answer we have found to this is the wishbone linkage with torsion bar suspension. This is similar to the scheme used on the Citroen and Chenard-Walcker without of course the front drive to the road wheels. The lower links to the front wheel yokes can be long or short as desired, and we have had experience with both types. This is rather a matter of what sort of steering layout works in better, and the general compromise decided for the steering effects. The longer link as we know maintains the track constant, can be arranged with a higher rolling centre, requires only one pivoted lever for the steering linkage but has more reaction on the steering. The short bottom link giving approximately parallel motion has the minimum of steering reaction, not such a high rolling centre, although the links can be sloped to favour this, track varies more, and steering | ||