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).
Nominal and actual sizes of Dunlop and Michelin tyres for the 40/50 HP chassis.
| Identifier | ExFiles\Box 81\1\ scan0166 | |
| Date | 29th December 1921 | |
| X990 W/S. C. C. Hs.{Lord Ernest Hives - Chair} C. FD.{Frank Dodd - Bodies} 40/50. HP. CHASSIS. RE SIZES OF TYRES. ------------------- Referring to your memo Sg{Arthur F. Sidgreaves - MD}4/YG. 26.11.21. we have now received from the Dunlop Company the nominal and actual sizes of tyres they supply to us, which are as follows:- BEADED EDGE TYRES. CANVAS CORD. Dia. Width. Dia. Width. 895 x 135 33.4" 4.92" 34.9" 5.44" 895 x 150 34.7" 5.55" 36.6" 6.07" STRAIGHT SIDE TYRES. CORD. 32 x 4½" 33.5" 5" 33 x 5" 35" 5.65" MICHELIN CABLE TYRE SIZES are:- BEADED EDGE TYRES. 895 x 135 34¾ diameter. 895 x 150 36" " From the foregoing it will be seen that the 895 x 150 Dunlop Cord Tyre is larger than anything we have hitherto fitted, and as the large tyres take away all the advantages we get by reducing the Rear Axle Ratio, we should not recommend any tyre larger than the following:- | ||