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).
Letter discussing the complexities of steering design, comparing Marles Steering to others, and noting its performance.
| Identifier | ExFiles\Box 28\2\ Scan042 | |
| Date | 17th August 1932 | |
| Messrs. Rolls-Royce Ltd., Derby. Contd 2. 17.8.32. of load and springing have to be taken into consideration in chassis design, apart from steering, which nevertheless may militate against the factors providing for an ideal steering lay-out, and for these reasons a compromise may have to be resorted to by slightly reducing the efficiency of the steering gear itself. It is not possible to arrive at a compromise by calculation, because road reactions are so varied and complicated, and quite different performances are given on different roads, and also on the same roads by similar cars of different makes. For these reasons, we have various helix angles for each size and type of gear, enabling us after a few road experiments to satisfy any particular conditions. Referring again to your question in your letter of the 10th instant as to whether there is any large car comparable to your Phantom II fitted with Marles steering, we gave you a long list of fast-passenger vehicles which have standardised Marles, but there are few cars in this country comparable with the Rolls-Royce. It may, however, be of interest that Marles have been standardised on Austro-Daimler cars for some years, and it is also fitted in this country to Isotta Fraschini. The writer has personally tested the latter car at various speeds and can vouch for its performance on that model with regard to road re-action. It may also be of interest to note that Marles Steering has been for many years the only steering selected for the cars which have obtained the world's record for speed, up to 253 miles per hour, and we have many expressions of satisfaction from Sir Malcolm Campbell, Sir Henry Segrave, Parry Thomas and others as to the steering performance under those severe conditions. The distinctive features of the Marles Steering are its ease, smoothness, freedom from backlash, and above all its lasting qualities due to the purely rolling action of its hardened alloy-steel parts working in oil. The performance of the Marles-Weller is very similar with the addition that it can be made more resistant to road shocks where these are troublesome. We would suggest that for trial purposes we send you - 2 - | ||