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).
Customer complaints of 'clonks' on 6½ & 8-litre Bentley wheels and the technical specifications of the hubs used.
| Identifier | ExFiles\Box 159\7\ scan0188 | |
| Date | 1st March 1938 | |
| 261? K {Mr Kilner} /W. Rm {William Robotham - Chief Engineer} /Gry. {Shadwell Grylls} Pk/KC/DPB/1.3.38. 6½ & 8-litre BENTLEY. Thanks for your Rm {William Robotham - Chief Engineer} /Gry. {Shadwell Grylls} 4/AP.25.2.39. We received comparatively few complaints from customers of "clonks" on torque reversals primarily due to the fact that the "eared" type wheel lock rings were brutally tightened up with a 4lb copper alloy hammer. These complaints were invariably cured by removing the wheels, greasing the splines and hub tapers and re-tightening the eared lock nuts and if this operation was carried out as a standard routine job at 2,500 - 3,000 miles, the cure remained permanent under ordinary conditions. We had one exceptional case; a hard driver of an 8-litre, who always suffered from "clonk" until Messrs Rudge (Mr.E.E.Aylward) produced a set of special lock rings which had been modified by fitting a phospher bronze cone into the lock ring for its bearing on to the outer taper of the wheel shell. This method proved to be effective. Apart from this case, it could not be said that "wheel clonks" worried us very much. For your information, I give below the types of hubs used, together with the principal conditions under which they were used:- 6½-LITRE. No. of hub used - No.62. Spline O.D. 3.25". Root of Spline " 3.125" Weight of complete Saloon. 44cwt 3qrs. Max.B.H.P. at 3,500.r.p.m. 140 - 180. Rear axle Ratio 4.16 & 3.84. Type size. 33" x 6.75" & 7" x 21". 8-LITRE. No. of hub used - No.80. Spline O.D. 4". Root of spline " 3.875" Weight of complete Saloon. 51cwt. Max B.H.P. at 3,500.r.p.m. 180 - 220. Rear axle Ratio 3.53 & 3.84. Tyre Size. 7" x 21". Other troubles with Rudge wheels can be summed up as | ||