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).
Report differentiating between 'sticking' and 'heavy' steering, discussing load, tyres, and steering ratios.
| Identifier | ExFiles\Box 154\3\ scan0032 | |
| Date | 1st August 1927 guessed | |
| contd :- -3- Effect of load on sticking. Another peculiarity that we have observed is that a worm and nut will either tighten up at almost any reasonable load or not tighten up at all i.e. with a good worm and nut properly lubricated we have run up to 3500 lbs. load and retained reversibility with no noticeable alteration in the value of k . With a bad sample we have had sticking under a load of 1200 lbs. Heavy steerings. We should like to differentiate between 'sticking' and 'heavy' steering. As the width of tyre tread and weight on the front of the car increase, and the tyre pressure decreases the steering becomes progressively heavier. With 30 lbs. tyre pressure and the best steering we can produce it requires a very abnormal effort to move the front wheels with a car absolutely stationary on a concrete road. This appears to be something that is done every day in the Sates, though quite exceptional over here. We believe that this was Mr. Fuller's complaint with the Derby steering and American tyres. The obvious solution appears to be a lower over-all steering ratio while retaining the same worm and nut. Our solex objection to a lower ratio is that it lessens manoueverability in traffic. OY. considered that it might spoil high speed control. Working with short pendulum levers we have not found this to be the case. Our present standard front tyres are 4 1/2" tread width and 40 lbs/sq.in. pressure. On the whole we do not find that this gives bad riding while it gives a better steering for shunting and high speed wobbles. Nevertheless, we ourselves contd :- | ||