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).
Advantages and performance characteristics of 'Super-cushion' tires.
| Identifier | ExFiles\Box 53\2\ Scan028 | |
| Date | 4th August 1923 guessed | |
| Oy2-N-8425 -2- between wheel housings of 1" (44" to 45"), decrease in radius in corner of wheel housing from 5" to 3", and increase in width of tire well in front mudguard from 6" to 7 3/4". These "Super-cushion" tires show unmistakably the following advantages: (1) Great improvement in road traction Ruts, slippery streets, car tracks and snow do not cause skidding or swerving. Chains are unnecessary in the worst weather of the winter, even though three-foot drifts were encountered. (2) Great improvement in braking By pressing with full force on the brake pedal on this car it is possible to throw the passengers off the seats without causing the rear axle to jump (no rear shock absorbers fitted). We cannot see that front wheel brakes can pull up a car with safety to the occupants any quicker than this. (3) Practical elimination of "chunking" and other transmission noises by eliminating all violent vertical movements of the rear axle. (4) Increased mileage 10,000 miles on Rolls-Royce - still shows full tread markings 4,000 " " " - with no recognizable wear (5) Improved riding qualities, especially marked on very rough broken road surfaces, where the roughness of the surface is not transmitted to the occupants. (6) General softening of the small car and body vibrations. (7) Decreased necessity of inflation On my own car after being inflated to 30 lbs. in the middle of February, it has only been necessary to use a few strokes of the handpump on two of the tires within the last two weeks. Tires have run 4000 miles. (8) Increased ease of hand inflation if necessary, because of low pressure. (9) Decreased wear and development of slack in spring shackles. With 33x5's, these require adjustment every 5000 miles. With 32x6's, they are in good condition after 10,000. (10) The evidence so far points to decreased heating in fast touring, apparently due to greater radiating surface or less power loss in deflecting fabric. This is borne out by the remarkable mileage obtained. It is known that Lincoln, Packard, General Motors (including Cadillac, Buick, and the smaller cars), Marmon, and others, are announcing the super-cushion tires for their standard models as soon as adequate supplies are placed on the market. | ||