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).
Comparison of the safety features of tyre rim designs, specifically contrasting Firestone and Goodyear types.
| Identifier | ExFiles\Box 42\4\ Scan153 | |
| Date | 25th June 1920 | |
| Contd. -3- June, 25th 1920. safer than any other make (they holding the basic patents) when the tyre is inflated, because as lognas there is any air in the tyre at all to press the detachable flange outwards, this flange securely locks the spring ring in place, whereas on the Goodyear and other types the ring is only held in by a wedgeing action and can theoretically be forced out by centrifugal force, especially if the tyre is half deflated and is pushed over in rounding a corner. I do not hear that this has ever happened with a Goodyear rim on the road, but am told that the racing men over here drill the rim of the Goosyear or lock ring of the Firestone and put split pins through, half a dozen or more on each wheel, as a safeguard against the loose pieces flying off. The further claim of the Firestone people in that the conditions of our test in England and do not exactly represent the conditions of practice, where the burst occurs at the high speed and the car is brought to a standstill in a few seconds thereafter. Here they claim that while air remains in the tyre, or even afterwards so long as the swerving is not too bad, the loose flange is held out over the lock ring which therefore cannot escape, whereas if the speed is high enough to overcome the inward spring of the Goodyear rim, this may push the tyre back by its wedging action and escape. Contd. | ||