Speedometer calibration for the 40/50 HP chassis, considering different wheel sizes and customer complaints.
| Identifier | ExFiles\Box 165\4\ img234 | |
| Date | 12th January 1934 | |
| WST Hs. {Lord Ernest Hives - Chair} BY {R.W. Bailey - Chief Engineer} /Cgh. {W Clough} 8/G. 12.1.34. 40/50 HP. CHASSIS - SPEEDOMETER. Before we introduced the contracted speedometer scale, the instruments were calibrated for 785 revs. per mile and the road wheels were 20" diameter. It was agreed by the Test and Experimental Departments that this calibration gave a high reading on the odometer. As a matter of fact certain customers found this out and complained. It was then agreed to introduce the contracted dial, and the correct calibration was 810 revs. per mile. When changing over to 19" wheels we altered the calibration figure in the direct proportion of 20/19" which gives a figure of 841. We therefore arranged for the instruments to be calibrated at 840 for 11/41 axle. From the above it will be noted that originally we increased the calibration figure by 35 revs. whereas you are now asking us to reduce the figure by 50 revs., which according to the above would make the instruments read faster than the original ones which were complained of. Before making any alteration we think that the matter should be further considered. BY {R.W. Bailey - Chief Engineer} /Cgh. {W Clough} | ||
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).