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 discussing comparative tyre tests and recommended pressures for a Bentley chassis.
| Identifier | ExFiles\Box 157\1\ scan0211 | |
| Date | 8th July 1935 | |
| DUNLOP RUBBER CO.,LTD. TELEGRAPHIC ADDRESS: "DUNLOPS, PHONE, BIRMINGHAM" TELEPHONE: ERDINGTON 2121 (P.B.X) EXTENSION No. 395. YOUR REF: OUR REF: HEP/LW.123. FORT DUNLOP ERDINGTON BIRMINGHAM Messrs. Rolls Royce Limited, DERBY. For the attention of W.A.Robotham, Esq. 8th July, 1935. Dear Sirs, Confirming the writer's call on the 5th inst., we understand that after certain comparative tests with standard 18" equipment on the Bentley chassis, as against 16" E.L.P., the latter tyres were found to be more "lively" in performance, and we feel that this is probably due to the fact that to obtain an improvement in ride the pressures in the E.L.P tyres - which we believe were 6.50-16 - would have to be considerably lower than your standard figures. We have on record 5.50-18 pressures as 30-lbs. rear, 35-lbs. front and we believe that whilst the rear pressure is called for by the fully laden weight on this axle, the figure of 35-lbs. for the front is recommended bearing in mind certain desirable features on the steering. To obtain an improvement in ride with the 6.50-16 equipment, therefore, pressures should be respectively 27-lbs and 24-lbs front and rear, but with these comparatively low pressures on a fast car on our English roads, an apparent lack of stability may be experienced. We very much appreciate your intention of writing us on this matter informing us of the details of tests which you carried out, so that we may have a further opportunity of considering the position. Yours faithfully, FOR THE DUNLOP RUBBER CO.,LIMITED. H.G.Price (Signature) Manager - Car Manfrs. Division. [Handwritten Note] H.{Arthur M. Hanbury - Head Complaints} Wyman What were the India Cushion tyres like at these pressures. | ||