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).
Wheel and tyre design, focusing on Michelin's innovations with lower pressure tyres and wheel construction.
| Identifier | ExFiles\Box 146\1\ scan0071 | |
| Date | 2nd November 1937 guessed | |
| - 4 - a great saving in the wear and tear on a car, as well as unequalled road-holding qualities and freedom from skid, not to mention the enhanced comfort due to lower tyre pressure. x x x Messrs. Michelin, however, wend a step further, and tackling the whole problem of the wheel, of which after all, the tyre is but a component, have improved it in the same proportions. The wheel as we now know it consists of a fairly thick rim and a plain, flat or convex disc, that is continually subjected to flexions; this, we feel in our bones, is not scientifically sound. Moreover a wheel with a rim of the classic type, wide enough to take a "Pilot" tyre, would of necessity mean sufficient weight to neutralise the gain of the lighter tyre. Messrs. Michelin, therefore, set methodically to work on the wheel problem. Why were rims made thick and therefore heavy? Because, while maintaining continuity with the hub, they had to stand up to high tyre pressure. A thinner rim should therefore be perfectly satisfactory with a lower pressure. The simplest thing, then, was to relieve the rim of some of the pressure-strain, and to ensure continuity with the hub by a method where each component part would carry its fair share of strain - which, when all is said and done, represents maximum efficiency. | ||