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).
Straight-sided cord tyres, including a decision to use them on the 'Goshawk' experimental cars and test results on performance.
| Identifier | Morton\M1.1\ img038 | |
| Date | 22th June 1921 | |
| From R.{Sir Henry Royce} Rolls-Royce of America, Inc. (For the attention of...) X4050 X3056 ORIGINAL RECEIVED JUN 24 RE STRAIGHT SIDED CORD TYRES. I am very pleased to see from Mr. Hives report that the straight sided cord tyres are likely to be universal. * We think we ought to start up the "Goshawk" with this type,* and therefore the wheels and tyres for the experimental cars should be ordered of this pattern. It is agreed that the springing must be well damped with this class of tyre, but if it should lessen the cost of running cars it is a decided advantage. As far as my own tests are concerned, I have obtained very comfortable and economical running with the tyre pressure about that suggested by Mr. Hives. At the same time I obtained very good petrol consumption, namely, about 18 miles per gallon on our 40/50 H.P., just natural conditions and fairly high speed driving over 50/100 mile journeys. In case of light bodies where the back wheels carry so much less weight, this matter of tyre pressure in the back wheels becomes increasingly important, especially on certain roads, bumpy, or pot-holey. R.{Sir Henry Royce} | ||