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).
Technical comparison between the 'Pilot' and 'Superconfort' tyres, detailing differences in rim size, section, weight, and performance.
Identifier | ExFiles\Box 146\1\ scan0070 | |
Date | 2nd November 1937 guessed | |
- 3 - First, the "Pilot" takes a wide rim - I 3/I6" wider than the rim made to fit the "Superconfort" of corresponding size. This, combined with its section which, instead of being circular, is in the form of a capital "D", the straight line representing the well of the rim, must obviously do away with any tendancy to wobble. Secondly, the outer cover of the "Pilot" does not flex in the same way as that of the "Superconfort", but to arrive at this it was necessary to line it with a special type of canvas that would absolutely prevent the tyre from "flattening" on corners or on those over-cambered roads that are still all too common. The "Pilot" shows something between 35 and 40% more "drift resistance" than the "Superconfort", a fact that not only offers tremendous advantages that will be referred to later on, but opens up an entirely new vista of possibilities. But there is more to come. The "Pilot" tyre, although larger than the "Superconfort", is not only lighter but actually stronger, inasmuch as it always retains a normal working position whatever the strain imposed upon it. For instance, in the 150/40 size, a "Superconfort" complete with inner tube weighs about 23 lbs., while the "Pilot" weighs little more than I8 I/2 lbs., a gain of 4 I/2 lbs. all the more valuable in that they are gained on the periphery, thereby reducing gyroscopic effects and improving acceleration and braking. The "Pilot" is cut on the "Stop" principle, but a new manufacturing process has increased road-grip by 20% in the case of a new tyre, and by as much as 50% in the case of half- to completely worn out tyres, as experiments have proved. This means | ||