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).
Comparing Goodyear straight-sided tyres with diamond stud clincher tyres regarding car handling.
| Identifier | ExFiles\Box 157\5\ scan0022 | |
| Date | 31th March 1921 | |
| W/S X 3926 To Cx.{Major Len W. Cox - Advertising Manager} from Hs.{Lord Ernest Hives - Chair} Hs{Lord Ernest Hives - Chair}5/LG31.3.21. X 3926 GOODYEAR STRAIGHT-SIDED TYRES. With reference to your Cx{Major Len W. Cox - Advertising Manager}8/WM24.3.21 attached. The tyres which were condemned by Derby were the Goodyear diamond stud clincher pattern. At that time we had not seen the Goodyear straight-sided tyres. We have since, however, tested the Goodyear straight-sided tyres and find that they are practically free from the faults which were in the clincher pattern. The reason for this is that the proportions of the diamond pads have been altered and they are not nearly as deep, and, therefore, not as flexible sideways. The effect we get with the clincher type diamond stud tyre is that the car wanders and is difficult to keep straight. It has been thought that this is due to the tyres with the deep diamond pads being very flexible sideways. It allows the frame to move in relation to the wheels. As the control sphere for the rear axle is fixed to the frame and moves with the frame, there is a tendency for this side flexibility to steer the car. As we have pointed out previously, however, the Goodyear straight-sided tyres do not produce this same effect. HS.{Lord Ernest Hives - Chair} | ||