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).
Preliminary steering and damper setting tests for the 12-EX car.
| Identifier | ExFiles\Box 17\3\ Scan064 | |
| Date | 1st September 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} X7430 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}1/LG1.9.26. 74565 (crossed out) 7457 12-EX CAR - STEERING TESTS. Below are preliminary tests received from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} in France on the steering of 12-EX car:- We have endeavoured today to find the best damper setting. The rear were 100 lbs. and 18 lbs., the 18 lbs. being due to too large an air vent as previously mentioned. We find 80 lbs. down and 60 lbs. up give excellent control on bad roads. Too much downward gives a nasty kick in the small of the back over big bumps. We have put the front to 55 and 75 lbs. but the greater upward loading seems to give harsher riding, though it is better for overcoming wobbles. In our opinion, we shall not do much better than our present 35 - 75 on the front for all round conditions. We believe, as far as our tests have gone, that the side steering tube to F.75379 with 75 lbs. set-up is a definite improvement with regard to wobbles. With no front dampers, and the worst pair of 6" tyres, the car can be driven at all speeds without a wobble building up, although certainly there are signs that the car would like to shimmy: this is with friction - Front axle jacked up 4.5 lbs. to start - 2 lbs. afterwards. " " " on iron plate 15 " " " - 12 " " that is, the steering is really very light. With 6.75" Dunlops or 6.2" Michelins, this steering is undoubtedly preferable to that of Summers Phantom (standard .720 steering). It should be contd :- | ||