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).
Effects of low pressure tyres and tyre wear on the steering of the 40/50 HP model.
| Identifier | ExFiles\Box 39\2\ Scan191 | |
| Date | 29th October 1926 | |
| To BY.{R.W. Bailey - Chief Engineer} from Hs.{Lord Ernest Hives - Chair}/Ru. X3538 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}6/LG29.10.26. LOW PRESSURE TYRES ON 40/50 HP. X4565 X4430 With the adoption of low pressure tyres, the steering susceptibility to small defects in these items has become more and more pronounced. The most important factor in connection with low pressure tyres on the front axle of the 40/50 HP. is the inflation pressure. This should be 40 lbs/sq.in. If the pressure falls much below this, the steering may be spoilt at high speeds and will certainly become heavy for traffic work, while the resultant increase in comfort will not be very noticeable to the passengers in the rear seats. Should the steering, at any time, show any undesirable features at high speeds, the first point to be investigated should be the tyres. Covers that have been on the rear, especially if subjected to a large amount of braking, should not be used on the front. The reason for this is that if the tyre has a flat on it due to the wheel being locked at some time, it is useless to fit it on the front axle and expect it to function satisfactorily, even if correctly balanced because the tread irregularity will transmit a periodic force to the steering worm gear which will prove very objectionable at high speeds. The same reasoning applies to tyre wear. If due to particularly bad road surfaces a tyre tread has worn very quickly, its surface may become somewhat irregular. contd :- | ||