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 regarding Drop Centre Rim modifications and international standards.
| Identifier | ExFiles\Box 45\2\ Scan285 | |
| Date | 9th August 1930 guessed | |
| COPY. THE DUNLOP RUBBER CO.LTD., Our Ref: Technical Director. FORT DUNLOP, ERDINGTON. BIRMINGHAM. Messrs Rolls-Royce Ltd. DERBY. Attention of Maurice Olley Esq., Dear Mr Olley, I must apologise for the delay in replying to your letter of the 15th.inst., The fact is I have been daily expecting news from America which would enable me to write you quite definitely. This news has now come to hand, though at the moment only in cable form. The cable reads thus:- "Drop Centre proposal by Goodyear with Dunlop modification adopted as recommended practice". This is the result of a long series of consultations between ourselves, Goodyear, and other American manufacturers, with a view to adopting agreed dimensions for Drop Centre Rims, which could be officially adopted as International Standards. In this, our efforts have now been successful, and of the rim sizes which interest you there is the rim having an inside width of 4.00" and a ledge width of .810". This rim differs from the section shown in the Tire and Rim Association 1930 Year Book in the depth of the well employed. There has been no conflict of opinion as between ourselves and American Manufacturers on the desirability of increasing the ledge width over that we previously used. This has been rendered necessary by the heavier construction of tyres now so generally used, providing a more bulky bead which wants a wider seating width. This wider seating naturally affects the total width of the rim. It was largely on the question of well depth and flange height that we were not in agreement with American proposals, but on thus they have now accepted our recommendations. This means that just as soon as our new rims can be produced, the same rims will be available - both in this country and in America for your purpose. Continued. | ||