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).
Tyre and rim safety, comparing Goodyear and Firestone designs and the risk of components detaching.
| Identifier | ExFiles\Box 42\4\ Scan137 | |
| Date | 25th June 1920 | |
| To: Rolls-Royce Ltd. - 3 inflated, because as long as there is any air in the tire 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 wedging 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 Goodyear 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 is that the conditions of our test in England 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 tire, 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. It becomes a question whether some sort of locking device is not desirable, and we would be glad to hear whether | ||