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).
Fitting Michelin wheels to the 20 HP chassis, detailing required axle modifications.
| Identifier | ExFiles\Box 49\1\ Scan071 | |
| Date | 3rd May 1919 | |
| Extract from E1/G3.5.19. X.3482 X.3493./ RE 20 H.P. AND NEW 50 H.P. CHASSIS. (6) MICHELIN WHEELS ON 20 HP. CHASSIS. On consideration of the 20 HP. back and front axle designs, it was thought that the small model Michelin wheels could be used, if only the bore were enlarged from 85mm. to about 95 mm. without any further alteration. This necessitates some alteration to the rear axle however. An alternative design of back axle is to be drawn in which a smaller size of outer ball bearing is to be shewn in the hub; this latter being obtained by a reduction in the axle driving shaft, where it passes through the axle tube on its way to the driving serrations, which are outside of the axle tube. It was thought that an immediate decision regarding these Michelin wheels was not possible, and that the designs for both twin and single wheels must be fully worked out for the 20 HP. which will be done in due course. | ||