Letter to Dunlop Tire and Rubber Corporation discussing drop centre rim designs and international standards.
| Identifier | ExFiles\Box 158\1\ scan0061 | |
| Date | 21th February 1928 | |
| C O P Y Technical Director February 21st, 1928. Mr. J. {Mr Johnson W.M.} L. Collyer, Dunlop Tire and Rubber Corporation, Buffalo, U.S.A. Dear Mr. Collyer: I received your telegram No. 17 and cabled you today as per enclosed confirmation. I am also sending you under separate cover twelve blue prints of our D.L. 2202 E. {Mr Elliott - Chief Engineer} showing the current standard drop centre rim. These rims remain with us to the same sectional dimensions as standard flat base straight side rims - that is, they have the same flange height and contour, and the same internal width. The drop centre is provided within the limits of the standard flat base rim widths. These rims are substantially the same as those which we have been issuing with the most complete success since June 1924. The only differences that have been made have been in slight modifications of the depth of the drop centre. In regard to this feature, our object has been all through to provide drop centres no deeper than is necessary to enable the tyres to be easily handled in fixing and detaching. Any excess of depth of the drop centre not only involves extra cost in tubes, but also makes a cover more liable to leave the rim when running completely deflated. (In this respect we find that the drop centre rim used by Ford with its greater depth of drop centre and lower flange height, permits a liability for the tyre to leave the rim when deflated, which does not exist with our rims. This may not be regarded as important, and clearly the Ford Co. know what their experience has been on this point, but we do not like it.) We have never had any complaints about the difficulty of fitting or detaching our tyres on rims with wells of the depths shown on these prints. We are very glad to know from your telegram that these rims will be given serious consideration, and I sincerely hope that it will be found possible to get these sectional dimensions adopted as American standard. We are most anxious to see one International range of drop centre rims in use, and to secure that end, we would willingly do everything that is possible in the direction of accepting minor modifications if that would help to secure International agreement, but of course, we could not accept modifications which would interfere with the interchangeability of tyres on the millions of our rims which are already in use throughout the world. (Continued) | ||
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).