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 to Dunlop Rubber Co. Ltd. concerning the testing of tyre treads to avoid high-speed wobbles on the 40/50 HP chassis.
| Identifier | ExFiles\Box 45\1\ Scan368 | |
| Date | 15th September 1926 | |
| X4050 c. to EY. Expl: Dept: Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}3/LG. 15th. Sept. 1926. 74565 - Paull Esq., The Dunlop Rubber Co. Ltd., Fort Dunlop, Erdington, Birmingham. Dear Sir, From a recent conversation which our Mr. Bailey had with Col. Matthews, it appears that some misapprehension has arisen with regard to our actual feeling towards the triple stud tread. So far, we have not tried a triple stud tyre experimentally which could under any circumstances be fitted to our 40/50 HP. chassis. We have never tried a high pressure straight-sided tyre, or a 6.75" balloon tyre with the triple stud tread. The 6" tyre which we have tried has been rejected owing to its very definite tendency to high speed wobble. From our experience with the 6.75" tyre with traction tread, we feel that it is very probable that this tyre will also be ruled out of court when it is equipped with a triple stud tread. We are therefore faced with the position that in all probability we shall not be able to adopt well base wheels and tyres on our 40/50 HP. car owing to the tendency of the triple stud tread to promote high speed wobbles. During our recent visit, we endeavoured to emphasize that high speed wobbles was a subject upon which there could be no question of compromise. Under the circumstances we would repeat our request that you will endeavour to conduct tests at the earliest possible moment to ascertain the relative effects of different tread designs upon the high speed wobbling propensities of various sizes of tyre, so that you will be able to assure us when submitting further treads for test that these will not increase our present difficulties with regard to 'shimmy'. Yours faithfully, | ||