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).
Analysis of historical wheel and hub assembly issues, comparing different component designs.
| Identifier | ExFiles\Box 159\7\ scan0189 | |
| Date | 1st March 1938 guessed | |
| - 2 - follows:- (1) Loose spokes which reached a peak around March 1930, and which trouble was ultimately eliminated by using heavier gauge spokes. (2) Split wheel shells; few in number (3) around November 1930. This was overcome by thickening up the wheel shells. (3) Two piece wheel shells, which if the shell split caused a wheel to collapse. This two piece method of construction was abandoned in so far as B.M.Ltd.were concerned around November 1930. Finally, (a) We are touch and go with our present Bentley in so far as "wheel clonks" are concerned, unless the hub caps are kept very tight. (b) The liberal use of grease seemed to be helpful on the old type cars. (c) Have you compared the 8-litre hub shell and lock ring characteristics with those that you are using? This hub gives little or no trouble, with the exception of the one case mentioned above. A comparison of this type hub with the 3 1/2-litre type shews that it is slightly larger in spline outer diameter, but the lock ring is thicker in section on the taper that makes contact with the outer wheel taper. If you examine the 3 3/4 or 4 1/2-litre wheel lock ring, you will find that the outer flange tapers off towards the wheel edge of the taper, becoming thinner in section in consequence, whereas the Bentley is parallel and considerably thicker. Is this the solution in that the wedging action of the combined lock ring that you are using is, owing to its reduced thickness, less effective? I attach sketches shewing:- (1) The thickness of the standard lock ring at that point. (2) The manner in which Messrs.Rudge modified a set of lock rings with the phospher bronze insert for the one case of clonk for which we could not effect a cure. (3) A section of the 3 1/2-litre lock ring. | ||