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).
Safety implications and reputational risk of wheel wobble caused by larger, lower-pressure tyres at high speeds.
| Identifier | ExFiles\Box 29\1\ Scan243 | |
| Date | 2nd September 1926 | |
| To Hs.{Lord Ernest Hives - Chair} from BJ. (COPY) c. to R.{Sir Henry Royce} c. to Wor.{Arthur Wormald - General Works Manager} c. to EV.{Ivan Evernden - coachwork} c. to PN.{Mr Northey} c. to CWB. LARGE SECTION TYRES. I think we are all in accord that the sooner we can adopt a larger tyre and lower pressure than we are using now it should be done, provided it will not cause any risk to the safety of the customer. Some few customers tell us that they really only want a closed car for luxury purposes, but from experience we have learned that this statement can practically never be depended on, as sooner or later, either the customer is in a hurry or the car is being used by his friends, and it is run at high speeds - probably well over 60 miles an hour. Therefore, unless we fitted a governor which would prevent the car ever travelling at over 60 miles an hour it would never be safe to supply such a car that was at all unsafe over 60 miles an hour. Again, our cars may be sold by the customer at any moment to another person who may delight in speed. I think we must all accept the view that so long as we supply cars that are capable of going at over 60 miles an hour and we know that a dangerous wheel wobble may arise within the range of its speed, we must never supply such a car. We can never afford to supply cars which we know that under certain conditions may cause serious accidents and death, and ruin to our reputation. Since the introduction of front wheel brakes, the reports have increased throughout motoring circles as to the danger of wheel wobbles on Rolls-Royce cars and the present position is serious. Anything which may cure those rumours is very desirable; anything which may increase those rumours is extremely serious. Judging by the test made on 12-EX, wheel wobbles have occurred intermittently with these large size tyres, and so far we have not run a car with these tyres for a long distance which has been entirely free from wobbles. Until we have done so it would appear to be unsafe for us to deliver them to customers. We have arranged for PN.{Mr Northey} to test a closed Phantom in France, starting next week, fitted with lightened axle and our present standard tyres, in order to ascertain what will be a customer's opinion of the standard chassis which we are now making at Derby. It is, of course, essential that we should obtain this information as quickly as possible. Contd. | ||