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).
Several defects exhibited by the Bentley 111 chassis on the bump-rig.
| Identifier | ExFiles\Box 97\1\ scan0104 | |
| Date | 31th December 1937 | |
| BY.{R.W. Bailey - Chief Engineer} c. Rm.{William Robotham - Chief Engineer} c. Da{Bernard Day - Chassis Design}/BV. 200b DA.{Bernard Day - Chassis Design}2/G.31.12.37. 400 BENTLEY 111. CHASSIS. We understand that the Bentley 111 chassis now on the bump-rig has exhibited several defects :- (1). The frame continuously breaks up. (2). There is a continuous wheel flap. (3). The rubber bushes do not stand up for long, especially in the outer bearing of the upper wishbone. (4). These bearings also move endwise. (5). The chassis is difficult to keep on the drums. (5). We understand is common to all our chassis, but the Packard is free from this defect and is also free from (2). It was not run long enough to ascertain whether (1), (3) and (4) were any improvement on Bentley 111, but it is suggested that on Bentley (2) is influencing (1). In view of the marked difference in the behaviour of the two cars in respect to (2) and (5) we suggest that early information as to their relative characteristics in certain respects, is of importance. The relative flexibilities of the steerings around the pivots for instance, and the relative lateral flexibility of the chassis on the suspension might throw light on the wheel flap. The characteristic in this last respect of the complete car will no doubt be different from that of the chassis, even when loaded up to the equivalent weight, but the information would tend to shew when the difference lay. The other point on which we should like information, if possible, is the frequency of the wheel hop on both cars or alternatively the torsional rigidity about the centre line of the cars. As regards (3) it is suggested that bumping may be an unsuitable test for these bushes, as the cooling due to the cars motion is not present. (In the same way as it is necessary to pour water on the shock dampers when bumping). (4) We are told that the Inlox type bearing for the outer end of the upper triangle is very expensive. DA.{Bernard Day - Chassis Design} | ||