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).
The performance of Dunlop Cord well base wheels and tyres on an 8-EX car.
| Identifier | ExFiles\Box 42\1\ Scan028 | |
| Date | 25th January 1926 guessed | |
| not sent out 8-EX CAR. REPORT ON WELL BASE WHEELS AND TYRES. X3809 X8940a Dunlop Cord 6" for 21" rims. These tyres were fitted to 8-EX chassis with limousine body. The total weight of car during the tests was 2 tons. 19 cwts. Tyre pressures - Rear 50 lbs/sq.in. - Front 40 lbs/sq.in. Weight of front axle 1 ton. 7 cwts. 1 qr. " " rear " 1 " 12 " 0 " The tyres were run from Derby to France and the latter part of tests in France, and returning to Derby. We consider the tyres are an improvement on the present standard 33 X 5" straight side cord, for holding the road. They are much better in this respect in their non-skidding qualities. We do not consider there is much improvement in the riding of the car with these tyres fitted. They make the steering heavier and are inclined to drag on corners. We consider they are very noisy both at slow and high speeds. The pattern of the tread is square i.e., three rows. The tread on the front tyres wears uneven - the rear portion of the inner and outer squares of tread has worn considerably more than the leading edge. The wearing qualities of the tyres we should consider fair. The worst feature is that the tread of the tyres quickly wears away on the rear wheels leaving a flat surface with approximately 1/4" of rubber left. They were in this condition after 3,367 miles. contd :- | ||