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 W.A. Robotham discussing peculiar tyre wear, a proposed new tread design, and arrangements for testing.
| Identifier | ExFiles\Box 29\4\ Scan149 | |
| Date | 23th November 1933 | |
| 2. W.A. Robotham Esq. the inner shoulder ribs have worn more rapidly than the centre rib. We are sending you one rear tyre and one front tyre so that you can judge for yourself the peculiar wear on the front tyre and consider the possibility of it being due to some mechanical action such as front axle whip. Our experts are inclined to the opinion that this peculiar wear on the front tyres might account, to some extent, for the alleged front wheel skidding at low speeds; they consider that this wear might be obviated by narrowing the centre rib slightly and making one or two alterations in the centre of the tread design, which alterations would not be noticeable to anyone except an expert. They are arranging immediately to have a mould cut embodying these alterations, which should be ready in five to six days' time. Subject to your approval, we propose sending you a set of these new tyres to Derby, also a set to Mr. Hancock in France. Would you like us also to offer Mr. W.O. Bentley a set for trial in London? There is one other point I should like to mention and that is that at the present moment there are a number of cars of different makes (a greater number than the number of Bentleys at present on the road) using tyres of the "Speed Special" tread design in various sizes and we have not received any complaints of skidding from any of them. Here are three reports from people who can be relied upon to give an unbiased opinion:- 18 H.P. Lanchester - very good nonskid on a showery day in London. 4 1/4 litre Bentley - excellent nonskid. 40/50 H.P. Rolls-Royce - excellent silence and nonskid - did 30 miles in 38 minutes on a wet road of varying surfaces without a suspicion of a skid. I do not for a moment wish you to infer from this that we think it is the fault of the Bentley, but we do think that owing to the Bentleys wonderful performance and braking and its comparative lightness of chassis which, together with the fact that it is somewhat under tyred, results in there being rather less than normal road adhesion, and it is for this reason we are so anxious for tests to be made actually on the Bentley itself, especially as careful enquiries to/ | ||