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).
Modifications to the lean of steering pivots to improve vehicle stability and address low speed wobble.
| Identifier | ExFiles\Box 2\B002_X168\ 00000001-page250 | |
| Date | 12th November 1915 | |
| To H.{Arthur M. Hanbury - Head Complaints} from HH. Copy to J.{Mr Johnson W.M.} " " RP. " " By.{R.W. Bailey - Chief Engineer} " " SA. Wor{Arthur Wormald - General Works Manager}/HH/L121115. November 12th. 1915. Re lean of Steering Pivots. We are making some packing pieces which will give 2° backward lean on the pivots. One pair of these packings will be sent to Mr Royce. With these fitted the pivots will have more backward lean than they have ever had. It used to be 1°, then it was increased to 1° - 30 mins., and the last alteration made it 0°-30 mins. I agree that leaning the pivots back this amount prevents any possibility of them tucking [handwritten: digging] in and it also makes it more stable at high speeds. I see no reason why we should give any more lean than the cars used to have, i.e. 1° - 50 mins. We are prepared to admit that as regards high speed 2° is better than 1° - 50 mins. in fact if high speed only is considered the pivots can be leaned back any amount. When running the car on Brooklands the pivots were leaned back 4 or 5 degrees, it was impossible to keep the car steady until this was done. Whatever we do we should not try and shut our eyes to the low speed wobbles, they are a complaint that we have got to overcome. I consider that a bad low speed wobble is the most alarming thing that could happen to a car. Low speed wobbles are never manifest on a new car, they develop as the | ||