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 discussing the adoption of the 21' rim as the standard diameter for low pressure tyres and production statistics.
| Identifier | ExFiles\Box 45\1\ Scan348 | |
| Date | 5th November 1925 | |
| Y4050 Telegraphic Address. "DUNLOPS, BIRMINGHAM." Telephone No. BIRMINGHAM CENTRAL 4108. PRIVATE BRANCH EXCHANGE, 25 LINES BY APPOINTMENT Registered Offices. DUNLOP HOUSE, 1, ALBANY ST.{Capt. P. R. Strong} LONDON, N.W.1. DUNLOP RUBBER CO LTD Founders of the Pneumatic Tyre Industry FORT DUNLOP, ERDINGTON, BIRMINGHAM. STATION: CASTLE BROMWICH. (MID. RY.) GOODS: TO DUNLOP SIDINGS, CASTLE BROMWICH. CAR ROUTE: TYBURN ROAD FROM STEELHOUSE LANE, TO FORT DUNLOP WORKS, CAR 63. WHEN REPLYING PLEASE QUOTE ON BOTH LETTER & ENVELOPE Development Supt. ALL COMMUNICATIONS TO BE ADDRESSED TO THE FIRM Messrs. Rolls Royce Ltd. DERBY. 5th Nov. 1925. For the attention of Mr. W.A. Robotham. Dear Sirs: We are in receipt of yours of the 31st ult. and in reply would say that the 21" diameter rim is now by far the most important diameter for low pressure tyres - in fact, we have adopted the 21" rim as the standard diameter for all cars on well base rims, other than light cars, for which the rim diameter is 19". You may be interested to know that the last return of rim production by the Tire and Rim Association of America gives the following percentages. 20" rims ........ 27.2% 21" " ........ 72.3% 22" " ........ 0.5% From which you will see that the preponderating importance of this diameter. With regard to the production of tyres to fit our well base rims - We would say that the Michelin Co. show several sizes of tyres in their present lists and we believe they are producing others. We have, however, arranged for the production of all sizes of tyres to fit our well base rims at our Factories in France and Germany, and both Goodyear and Goodrich Cos. are producing similar tyres. Many other British and American manufacturers are also engaged in producing such tyres and we think you need be under no anxiety as to the obtaining of replacements. We shall, of course, be only too glad to render you any assistance in this matter in any specific cases on hearing from you. For THE DUNLOP RUBBER CO LTD. W.H. Paull | ||