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).
Technical memorandum discussing potential modifications to steering, brakes, ground clearance, and wheel movement.
| Identifier | ExFiles\Box 100\1\ scan0094 | |
| Date | 25th February 1938 | |
| -3- Da{Bernard Day - Chassis Design}/Db.{Donald Bastow - Suspensions}4/N.25.2.38 Cont'd.{John DeLooze - Company Secretary} -------------------------- (6) Cont'd.{John DeLooze - Company Secretary} If the rim width were limited to 4.50", the correct width for the 6.50" section tyre of B.III, the lock angle of the outside wheel would become 29° for the 41° lock of the inside wheel. The increase of turning circle diameter then ranges from 1½ to 2½ ft. depending on the speed. Different steering levers for B.III and B.50 would enable the B.III to take full advantage of its narrower rim and this seems a reasonable solution. Retention of present out of centre point and present yoke piece implies front track of 56". Wider brake drums, the same width as the rear, accommodating 2½" wide shoes, can be easily accommodated with a pressed steel wheel. Their accommodation with a wire wheel implies spoking to one side of the rim only, as shown in PD.122. It is intended to send a print of this to Dunlop's for their comments. (7) Increased Ground Clearance. This is most easily achieved by the use of 17.00" rims instead of the 16.00" at present specified. Any other method implies alterations to the frame or to one or more of the major suspension pieces or both. Contrary to what was at first supposed the 17.00" rim does not help the steering ball joint foul with the rim and or tyre. (8) Increased wheel movement. If a foul between the cross steering tube and the opening in the torque arm on full lock and full rebound can be tolerated, then the total wheel movement can be increased to slightly over 7 inches (figures obtained from car 1.B.V. now in Experimental garage). A rough estimation of the resulting foul is approx. ½" in the conditions specified. Cont'd.{John DeLooze - Company Secretary} | ||