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).
Results of tyre trials on an Open Trials Car, focusing on noise and comfort.
| Identifier | ExFiles\Box 45\1\ Scan131 | |
| Date | 28th October 1920 | |
| COPY. PN{Mr Northey}25/DN/28.10.20. S/W. Hs.{Lord Ernest Hives - Chair} I have been running our Open Trials Car on the special Dunlop tyres with demountable rims, which you arranged I should try. I propose continuing to run on these tyres until Monday next, when the car goes into the Coachbuilders for certain work to be done. I have decided that the wheels shall then be taken off and that Dunlop Magnums be again fitted. My impression of the former tyres is that they are considerably more noisy than the Magnum, which are already much too noisy, and that the general comfort of the car has been much reduced by running these new tyres at 60 lbs. pressure. I have reduced the pressure to 45 lbs. per sq. inch, and the conditions are considerably improved, but the Dunlop Co. appears to have no information as to how far it is wise to go in reducing the air pressure, and I do not feel justified in carrying out experiments on one of our Trials cars of this nature. I hope that soon a form of tread will be devised and be available, which, whilst being effective will not cause most of our owners to think that our axles are unreasonably noisy. PN.{Mr Northey} | ||