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).
Dunlop tyres for the 40/50 and 20 HP models, including recommended tyre pressures and shock damper adjustments.
| Identifier | ExFiles\Box 39\2\ Scan176 | |
| Date | 27th October 1925 | |
| COPY. To C.J. from H.{Arthur M. Hanbury - Head Complaints} Copies to B.J. PN.{Mr Northey} R4/M27.10.25. Re TYRES. I understand that the Dunlop Co. are making us an especially good tyre for the 40/50, with a light pattern of wheel which also has waterproof rims. If these prove as good as they appear we should recommend them for all we are worth, so as to avoid customers fitting a heavier wheel or tyre, which is sure to be less satisfactory. As regards the tyres for the 20 HP. the semi-balloon ones which I have, appear to be particularly suitable for this model, which, owing to its smaller dimensions, cannot ride quite as well on a rough road. It is necessary to have the shock dampers of both our models rather more tightly set than in the past; it is imperative that the tyres shall be run at a lower pressure, and it seems as though for ordinary purposes 40 lbs. per sq. in. is about right for a light-weight 40/50, and 30 lbs. per sq.in. for the 20 HP. with 5¼" tyres. H.{Arthur M. Hanbury - Head Complaints} [Stamp: RECEIVED] | ||