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).
Letter from Dunlop Rubber Co Ltd. regarding big section tyres and offering a demonstration of low-pressure tyres to Mr. Royce.
| Identifier | ExFiles\Box 53\2\ Scan037 | |
| Date | 21th August 1923 guessed | |
| 2. away from them, and of course gets a much wider base rim which positively prevents rolling excepting at unduly low pressures. Personally I think it would be a mistake for you not to adopt the big Section tyre, namely 8" instead of 5" as there is a very considerable difference between the vertical displacement of such a tyre as compared with the 6" or 7" tyre. The fact, however, that we are working on a tyre of one constant bead base diameter of 20" makes it quite feasible & practical to over-size when required according to the weight of load of body carried by any particular chassis. The advantages to be gained by the use of Low Pressure Tyres can only really be demonstrated by taking the same car and changing the sets of tyres from normal to low pressure type. If Mr Royce would care to see an example on a small car as my 12 H.P. Rover, I could make arrangements to come down and demonstrate this. It will not be long now until we are able to get a set of wheels to suit your 20 H.P. car and we already have the first sample tyres made. Yours faithfully, FOR THE DUNLOP RUBBER CO LTD., [Signature] Experimental Engineer. | ||