Testing of Floatex body mounting on the Wraith chassis to assess tyre noise and rear axle shake.
| Identifier | ExFiles\Box 7\5\ X 604 Body-page069 | |
| Date | 8th February 1937 | |
| SECRET 10/HP 604. Rm. {William Robotham - Chief Engineer} c. Sg. {Arthur F. Sidgreaves - MD} Hs. {Lord Ernest Hives - Chair} Rm {William Robotham - Chief Engineer} /Les. Rm {William Robotham - Chief Engineer} /PD. Dn. SV. E.2/HP.8.2.37. Floatex Body Mounting on Wraith Chassis. We should like to have a test made for tyre noise on the Wraith as soon as time permits, to test the effect of the Floatex mounting on this particular feature. The Floatex mounting has been so arranged that it can be altered to solid mounting without much trouble as the fitting has been bolted on below from the body brackets, and can be withdrawn and replaced by solid distance pieces. With regard to the question of rear axle shake, we should also like a test made while the car is in its present position, to observe the amount of lateral movement between the body and the rear end of the frame, as we did on Phantom III, holding a pencil solid with the coachwork and allowing it to mark the frame. We have not used the lateral stays for the Wraith as we were relying on the lateral rigidity of the Floatex elements, but this experiment should tell us how rigid the Floatex is sideways. We included in our original instructions for the Wraith chassis rubber between the rear axle and the springs, and rubber bushes for the front ends of the rear springs. This was with a view to doing everything possible to minimise tyre noise, and we presume this is how the first chassis is equipped at the moment. If the Floatex mounting is found to be an improvement in respect to tyre noise then we may be able to dispense with the rubber bush for the front end of the rear spring, which will be an economy in weight and cost, and at the same time reduce the lateral flexibility of the rear axle mounting. An improvement in respect to reduced axle shake and better steerability of the car might result. Personally I feel that the low position of the road springs relative to Please FILE Have noted and have copy. Rm {William Robotham - Chief Engineer} /D | ||
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).