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).
Comparison table of steering conversions for 40/50 models to address complaints.
| Identifier | ExFiles\Box 17\3\ Scan250 | |
| Date | 1st May 1928 | |
| 40/50 CONVERSIONS FOR COMPLAINTS AIMING AT OVER-ALL RATIO OF 15/1. TABLE DATA: Column Headers: 1) SERIES: V, ORIGINAL CONVERSION, CONVERSION FOR STEERING COLS. 1 AND 2., 'B' 2, CONVERSION FOR 'B' 2 SERIES., 'F' 2, CONVERSION FOR 'F' 2 SERIES., 14 EX. E.A.C. 7 Row Data: LEAD: 1.125, .940, .825, .720, .720, .720, .720 PITCH DIA:: 1.400, 1.400, 1.400, 1.800, 1.800, 1.800, 1.800 HELIX ANGLE: 14°-20', 12°-4', 10° 36', 7° 15', 7° 15', 7° 15', 7° 15' Nº OF STARTS: 4, 4, 4, 3, 3, 3, 3 ANGLE OF CUTTER: 29°, 29°, 29°, 29°, 29°, 29°, 29° ROCKING LEVER: 2.300, 2.300, 2.300, 1.750, 1.750, 1.750, 1.500 PENDULUM LEVER: 9.500, 9.500, 9.500, 9.500, 11.000, 10.0, 7.500 SIDE STEERING LEVER: 8.000, 8.000, 8.000, 8.000, 9.225, 9.225, 9.500 LOCK ANGLES: L.H. 38° R.H. 32°, L.38° R.32°, L.38° R.32°, L.38° R.32°, L.38° R.32°, L.38° R.32°, L.38° R.32° LEVERAGE: 11/1, 13.6/1, 15/1, 13/1, 13/1, 14.3/1, 16.5/1 TURNS OF WHEEL: 2, 2.4, 2.65, 2.2, 2.250, 2.350, 3.000 Bottom Section (S.S. TUBE USED, SPRING RATING, MAXIMUM MOVEMENT, STRESS): - Column 'V': F.5007 F.4614 3,500 LBS/'' .250" TRAVEL - Column 'ORIGINAL CONVERSION': N.SCH. 2258 F.76787 F.76726 1500 LBS/1" .600 84,500 - Column 'CONVERSION FOR STEERING COLS. 1 AND 2.': THE VERY LOW RATIO MAY REQUIRE A SIDE STEERING TUBE END MODIFICATION TO PREVENT EXCESSIVE SPONGINESS. - Column ''B' 2': F.4614 3.500 LBS/'' .250" 84,500 - Column 'CONVERSION FOR 'B' 2 SERIES.': N.SCH. 2258 F.76787 1500 LBS/'' .600 84,500 - Column ''F' 2': N.SCH. 2258 F.76787 F.76726 1500 LBS/'' .600 84,500 - Column 'CONVERSION FOR 'F' 2 SERIES.': N.SCH. 2258 F.76787. F.76726 1500 LBS/1" .600 84,500. - Column '14 EX. E.A.C. 7': F.76108 F.76110 1400 LBS/1" .400 84,100 Vertical Note (Column 'CONVERSION FOR 'B' 2 SERIES.'): IN A NUMBER OF DISSATISFIED OWNERS NOT LARGE. SHORTER PENDULUM LEVERS CANNOT BE FITTED. IN EXCEPTIONAL CASES THEREFORE USE COL. 3 CONVERSION. | ||