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).
Experiments to reduce tyre noise on a Phantom III.
| Identifier | ExFiles\Box 157\1\ scan0222 | |
| Date | 16th October 1935 | |
| X1332 Sg.{Arthur F. Sidgreaves - MD} and Wor.{Arthur Wormald - General Works Manager} from E.{Mr Elliott - Chief Engineer} E.4/HP.16.10.35. C. Ex. Hs.{Lord Ernest Hives - Chair} Dy.{F R Danby} Mx.{John H Maddocks - Chief Proving Officer} La.{L. A. Archer} Da.{Bernard Day - Chassis Design} re Tyre Noise on Phantom 3. During the past week-end, in conjunction with Mx.{John H Maddocks - Chief Proving Officer} and La.{L. A. Archer} we carried out a number of experiments on 65-EX in connection with tyre noise. We ran a car first of all with the brake drums on the rear axle entirely removed, with the object of testing what amplifying effect, if any, the drums have. The result was there was not the slightest difference. We, therefore, concluded that the same answer would have been obtained with the front drums removed. We next tried the effect of the anti-roll rod being 'on' and 'off', as this was an easy experiment to make, and here again there was no change. A set of the standard Dunlop wheels fitted with 90 type Dunlop tyres were damped as thoroughly as possible by packing felt around the spokes, and pulling up discs of compressed wood pulp material with screws on each side of the wheel. These were fitted and a run was made which produced a distinct improvement in reduction of noise. We repeated the test with the damping stripped down to get an immediate comparison and the difference was clearly apparent. The next experiment tried was Dunlop wheels fitted with Goodrich tyres, and this was definitely the best result obtained up to that time. A check run was now made on the Cadillac and it was clear that this car reached a higher standard for tyre noise than anything obtained on Phantom 3. A test was also made without the rear-most body feet connected to the rear-most part of the frame, but this produced no change. A set of hubs was now prepared to take the | ||