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).
Various tyre specifications and their impact on vehicle gearing and hill-climbing performance.
| Identifier | ExFiles\Box 81\1\ scan0167 | |
| Date | 19th July 1917 | |
| - 2 - DUNLOP CANVAS & CORD TYRES. BEADED EDGE TYRES. CANVAS CORD. dia. width. dia. width. 895 x 135 33.4 4.92 895 x 150 34.7 5.55 34.9 5.44 STRAIGHT SIDE TYRES. CORD. 32 x 4½" 33.5 5.0 33 x 5" 35 5.65 MICHELIN CABLE TYRES. 895 x 135 33¾ diameter. GOODYEAR. 895 x 150 34¾ diameter. We have discussed this matter with the Experimental Dept. and Test Dept. and they agree with our recommendations. The point we wish to emphasize is that we have gone to a great deal of trouble in reducing the rear axle gear, in order to get better acceleration, and although we have previously recommended 895 x 135 Tyres for the front and 895 x 150 for the rear, now the 895 x 150 Cord tyre has come on the market, and this is approximately ½" larger in diameter than the 895 x 150 Canvas tyre, we strongly recommend that customers should be informed that by fitting either 895 x 150 Dunlop Cord or 895 x 150 Michelin Cable Tyres, they considerably increase the gear of the axle and decrease correspondingly its hill-climbing capacity. Will you kindly give this matter your careful consideration and let us have your views as soon as possible. BY.{R.W. Bailey - Chief Engineer} | ||