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).
Graph showing the increase in tyre radius with speed, alongside a discussion on the issue of tyre noise.
| Identifier | ExFiles\Box 158\1\ scan0019 | |
| Date | 14th January 1927 guessed | |
| contd :- -10- GRAPH: INCREASE IN RADIUS - INCHES SPEED - M.P.H. UPPER PLOT: INCREASE IN EFFECTIVE RADIUS OF 33 x 6.75 DUNLOP CORD BALLOON TYRE LOAD ON TYRE -1120 LBS. INFLATION PRESSURE 30 LBS/SQ IN. LOWER PLOT: 33 x 5 TYRE INFLATED TO 70 LBS SQ IN. CARRYING 1320 LBS LOAD (b) The question of noise. On a large car, tyre noise is a serious proposition. It is an unfortunate fact that if a tyre tread has good non-skid properties it will almost inevitably be noisy. Thus plain ribbed tyres are almost silent, traction tread inter-mediate, and triple stud produce quite an objectionable volume of sound. The main drawback to the triple stud is that the note it produces is singularly like that of a noisy rear axle. Balloon tyres usually have a lower note than the corresponding high pressure tyres but are very much more audible; it is advisable that contd :- | ||