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).
The effect of tyre tread shape and wear on steering effort for 40/50 HP and 20 HP models.
| Identifier | ExFiles\Box 53\3\ Scan061 | |
| Date | 23th June 1927 | |
| t4365. To Hm.{Capt. W. Hallam - Head Repairs} from Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. to BY.{R.W. Bailey - Chief Engineer} c. to CWB. c. to EP.{G. Eric Platford - Chief Quality Engineer} Hs{Lord Ernest Hives - Chair}/Rml/LG23.6.27. 40/50 HP. AND 20 HP. STEERING. X. 8430 X. 5430 X. 4050 X. 4565 We recommend that the following note is circulated to all Depots:- Tyres otherwise of the same dimensions with flat treads in contact with the road promote heavier steering than tyres with somewhat oval section treads. We can definitely appreciate this in our steering tests and it has been brought home very forcibly to the American Co. owing to the fact that nearly all the 6.75" balloon tyres in America have a road contact width of 5 1/2". When the new type buttressed tread Dunlop tyre is well worn so that the pattern is almost obliterated, the width of tread in contact with the road is considerably increased compared with that of a new tyre. This makes the steering noticeably heavier for town work. We therefore recommend that in complaints of heavy steering the newest tyres available on the car should be fitted to the front wheels and the chauffeur advised of the bene-fit he is likely to get from such tyres. In this connection, of course, inflation pressure is of vital importance. HS{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||