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).
Experiments to improve steering and reduce 'jellying' by altering the front axle assembly, which yielded no improvements.
| Identifier | ExFiles\Box 14\8\ Scan221 | |
| Date | 19th February 1930 guessed | |
| -6- to that of a close coupled saloon like 1-WJ. It will be appreciated that this question is somewhat complicated and involved and we are still working on it. Altering the Front Axle Assembly. We were unable to confirm the test that Da.{Bernard Day - Chassis Design} quoted of 20" wheels with 7" tyres being better than 21" wheels. We can find little possibility of improvement over the range of wheels and tyres that would be acceptable. We find, however, that if we increase the out of centre point of the wheels by .5", thereby increasing the track 1.00" we improve the steering somewhat and the "jellying" slightly. The following experiments were carried out giving no improvement :- (1) Various pivot leans tried from 4º to 2.5º. (2) Various side steering tube modifications. (3) Various alterations to steering geometry by altered steering arms, ball ends, etc. (4) Full range of tyres and wheels from 7" on 21" rims to 7" on 20" rims. (5) Radiator 30% lighter than standard with 1/3 moment of inertia of standard. (6) Two cwts. disposed centrally in front of the radiator, having little or no movement of inertia about the chassis centri line. (7) Various amounts of cross steering tube friction. (8) Engine feet tightened up to get the maximum rigidity out of the present design. (9) Torque arm control allowing free spring movement. (10) Chassis held rigidly in a horizontal plane by cables from the front dumb irons to the walls of the test house. This explodes Jeussaud de Lavan theory that a car with no differential in the back axle will not wobble as the front will be restrained from moving sideways. | ||