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).
Comparison and proposal for standardizing Marles steering on the 20/25 model.
| Identifier | ExFiles\Box 28\3\ Scan118 | |
| Date | 20th February 1935 | |
| 74094 To E.{Mr Elliott - Chief Engineer} from Da.{Bernard Day - Chassis Design} c. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Da.{Bernard Day - Chassis Design}1/HP.20.2.35. Marles Steering on 20/25. I expect it is appreciated that the comparison of the R.R. and Marles on the 20/25 is not a fair one. The wheel turns from full lock to full lock in the RR. steering is 2.25 and in the case of the Marles is 3.1. If we were allowed to have 3.1 turns on the RR. steering there is very little doubt we could put up a performance not very different from Marles. In spite of this low gearing, joggles can be felt on a smooth road with the Marles steering, but I cannot say how this compares with the standard RR. The slow steering was the driver's only criticism. The wheel turns on Marles cannot be reduced without alteration causing delay, and the 3.1 ratio is only obtained at the expense of a 10.15 pendulum lever, which spoils the geometry, especially on rebound. I have not seen any reports on the Marles steering which ran 10,000 miles, but I presume no troubles were experienced. What we are proposing to standardise however is not the same as this. In order not to cause delay it is intended to use practically a standard Marles steering. This differs from that tested in the following particulars:- As tested:- Column was a 2" dia.tube approx .125 thick, with adaptor at bottom fitting the 1.750 dia. screwed plug in steering box . Now proposed for standard. Column will be a 1.750 tube all the way, thickness of which can be made what we like. The bottom is attached to the box by a flange fitting instead of the | ||