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).
High-speed steering wobbles, potential causes like tyre imbalance, and comparisons between the New Phantom and Silver Ghost models.
| Identifier | ExFiles\Box 28\4\ Scan259 | |
| Date | 1st August 1925 | |
| To CJ PN{Mr Northey} Hs.{Lord Ernest Hives - Chair} } FROM R.{Sir Henry Royce} 457 R1/M/1.8.25. RE. STEERING. X.8430 X.457 X.4565 PN{Mr Northey}'s memo. received this morning is very alarming. I do not think however it can be quite as bad as it appears, otherwise we should have had very serious accidents in running the cars in France. I am asking Hs.{Lord Ernest Hives - Chair} to come here on Thursday especially about this subject and the effect of the vacuum feed on the slow running. Regarding the high speed steering wobbles we have done nothing in the design of the New PhantomCodename for PHANTOM I compared with the Silver Ghost that should have made any difference, and neither is there sufficient difference between the Silver Ghost before front wheel brakes, the present Silver Ghost, and the New PhantomCodename for PHANTOM I to make any material difference to the steering. It is possible that our steering is too free, and requires more damping. This I will enquire into, but we are anxiously awaiting a report from Hs.{Lord Ernest Hives - Chair} on the combinations we have lately suggested - that is - the damped pendulum lever, the slower steering, and the more irreversible steering. We have so far found no reason why our cars are worse than others. In many ways they are the same as the more recently adopted practice of the makers who should know most about high speed steering, such as Sunbeam, Delage etc. As I before reported there may be some slight differences in proportions, speed of steering, etc., but there is certainly no difference in the principles of the mechanism, and we have given a range of proportions which will enable Derby to find the best compromise. We have for some time been awaiting the results of the various devices. You will remember at first it was heavy steering, then it was road shocks, now it is high speed wobbles. For a long time past I have suggested and recommended slower steering, and our schemes go further than the best practice we know of, and it is possible we may have to look in some other direction for a cure to meet the immediate situation. Regarding tyres we believe that Hs.{Lord Ernest Hives - Chair} has reported that Dunlops are making their inner tubes in a way to get the max. out of balance - that is - they are not putting the joint and the extra thickness of rubber opposite the valve, but are putting the extra weight of rubber and the valve close together on one side of the wheel. PN.{Mr Northey} will perhaps tell us whether the car complained of had the wheels tested for balance. If both wheels are out of balance they can at times neutralise one another, and at other times add to each other to produce a contd :- | ||