Modifications for the Wraith II Independent Front Suspension to resolve issues found on the first car.
| Identifier | ExFiles\Box 9\5\ 05-page023 | |
| Date | 8th February 1937 | |
| SECRET To BY. {R.W. Bailey - Chief Engineer} Copy to Mr. Rm. {William Robotham - Chief Engineer} RMc. H.S. E {Mr Elliott - Chief Engineer} /Lid. {A. J. Lidsey} Rm {William Robotham - Chief Engineer} /Les. Handwritten: WS, 1044, 646 Wraith II Independent Front Suspension. --------------------------------------- We give below a series of modifications which are required to the Wraith II independent front suspension to clear up little difficulties which have been experienced in erecting the first car:- 1) Rivets attaching Water Excluder. It is reported that one of the rivets for attaching the water excluder to the front brakes causes a foul with the top triangle bearing boss on full lock. To overcome this difficulty we suggest that the rivets be moved round 12º against the direction of rotation of the wheel. This riveting is shown on N.Sch.4813. 2) External Pull-off Spring - Front Brake. The external pull-off spring to the front brakes is shown on N.Sch.4898, and its attachment to the brake lever is by means of a piece of bent stout wire such as we have used previously. It has been thought by the Expl. Dept. that the wire is not strong enough but we have shown by calculation that at the very most the stress cannot exceed 2700 lbs per square inch. It is suggested that the wire should be cadmium plated and a very free fit in the lever boss. Will you kindly instruct this to be done. 3) Brake Shoe Clearances. It is reported that on the first car the aluminium brake shoe and lining foul the dovetail pieces for locating the lining into the brake drum. The correct brake drum is shown on N.Sch.4851 and here we show the clearance between the shoe and the dovetail lining fixing, of 1/16". A similar clearance is shown between the shoe and the outer carrier plate. Apparently this clearance is inadequate to take care of the variations resulting from the limits, and we suggest that the width of the shoe be reduced from 1.750" to 1.625", so increasing the clearance to 1/8" each side. Will you kindly instruct this. Contd: | ||
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).