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).
Specifications table for 20 HP steering conversions to achieve a lower over-all ratio.
| Identifier | ExFiles\Box 106\3\ scan0212 | |
| Date | 8th May 1928 guessed | |
| 20 H.P. STEERING CONVERSIONS TO GIVE LOWER OVER-ALL RATIO. TABLE DATA: ROW HEADERS: SERIES. LEAD PITCH DIA: Nº OF STARTS HELIX ANGLE ROCKING SHAFT PEND LEVER. SIDE STEERING LEVER LEVERAGE. TURNS OF WHEEL. LOCK ANGLES. SIDE STEERING TUBE DETAILS. COLUMN 1: 'PREVIOUS TO F.{Mr Friese}' .930 1.035 3 15°·57' 1.750 10.00 7.500 8.9/1 1.7 L 41° R 36½° F51865 UNEQUAL SPRINGS COLUMN 2: 'TO 150 IN J' .930 1.035 3 15°·57' 1.750 10.650 8.000 9/1 1.8 L 41. R.{Sir Henry Royce} 40 FSL.584 SPRING F51863 11.50 LBS/1" 1.50 TRAVEL COLUMN 3: 'CONVERSION COLS 1 & 2' .750 1.035 3 12°·59' 1.750 10.65 8.000 11/1 2.2 L.41 R.40 N.SCH 2308 SPRINGS F.54759 600 LBS/1" .400 TRAVEL COLUMN 4: 'FROM 151 IN J.{Mr Johnson W.M.}' .700 1.500 3 8°·27' 1.400 10.000 9.000 11.3/1 2.1 L 41 R.33 N.SCH 2308 SPRINGS F.54759 600 LBS/1" COLUMN 5: '"M"' .700 1.500 3 8°·27' 1.400 8.250 8.00 12.2/1 2.25 L 41. R.33 N.SCH. 2308 SPRINGS F.54789 750 LBS/1" COLUMN 6: 'CONVERSION COLS 4 & 5' .700 1.500 3 8°·27' 1.400 8.250 9.000 13.7/1 2.5 L.41. R.33 N.SCH 2308 PROBABLY F.54754 900 LBS/" | ||