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).
Minutes of a conference to agree on the design geometry for the 'Myth' rear suspension system.
| Identifier | ExFiles\Box 161a\1\ scan0118 | |
| Date | 2nd October 1940 | |
| 1287 +373 COPY. To Rm.{William Robotham - Chief Engineer} c. to Rm{William Robotham - Chief Engineer}/WJH. Rm{William Robotham - Chief Engineer}/EAG. Rm{William Robotham - Chief Engineer}/GB. Ev{Ivan Evernden - coachwork}/DB.{Donald Bastow - Suspensions} Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} Ev.{Ivan Evernden - coachwork}10/JH.2.10.40. Minutes of Conference held at Park Leys Oct. 2nd, 1940. Subject - Myth Rear Suspension. Present Rm{William Robotham - Chief Engineer}/GB. Ev{Ivan Evernden - coachwork}/DB.{Donald Bastow - Suspensions} Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} & Ev.{Ivan Evernden - coachwork} The purpose of the meeting was to arrive at an agreement between the parties concerned on the design of the geometry of the rear suspension. A compromise in the matter of the following features was reached - a.{Mr Adams} Degree of understeer. b. Amount of prop. shaft pumping. c. Wheel size. d.{John DeLooze - Company Secretary} Rear spring shackle and its effect on spring rating with deflection. e.{Mr Elliott - Chief Engineer} Ground clearance. The following points were agreed to:- 1. The car should be drawn for 16 in. rims and 5 in. section tyres as standard (not 5.5 section as previously used). 2. The height of level top of frame at even keel shall remain at 13.350 ins. with the smaller tyres. 3. The car will be drawn at even keel which is .750 before full load position at the rear axle. 4. The front eye of the rear spring will be 4.000 ins. below the level top of the frame, and the rear eye .500 ins. above. Both rolled eyes shall be offset. 5. The inner diameter of the eye shall be .875 ins. 6. The top leaf thickness is .280 ins. 7. The distance between the axle centre line and the centre line of the top leaf shall remain at 2.312 ins. as drawn by Rm{William Robotham - Chief Engineer}/GB. 8. A spring so determined gives the following:- a.{Mr Adams} .550 ins. prop. shaft pumping on max. bump. b. 4.7% understeer under full load. c. Zero understeer with 2 up in front seat, assuming .875 in. deflection for the removal of the rear two passengers. R/W (G11 GZ) (11310 31-11-39) B'S 4321L | ||