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).
Analysis of wheel wobble and caster angles, comparing a design with a Master Chevrolet.
| Identifier | ExFiles\Box 170\3\ img042 | |
| Date | 14th July 1933 guessed | |
| -12- A careful check on the drums with the wheels first running backwards with negative caster and then running forward with positive caster, shows no appreciable difference in the production of wobble at various caster angles, whether the weight is behind the kingpin or ahead of the kingpin. The real argument against the pusher is that it requires more caster angle for a given 'road feel'. This is referred to later, and is leading to a redesign of our unit to bring the centre of gravity in line with the kingpin. The difference is that the Master Chevrolet has a "zero caster" condition on a high speed turn with 2° negative caster, or ¼ inch negative offset, whereas the TT job reaches the zero caster condition at 1-1/2° positive caster of 3/8 inch positive offset. 4. A fourth possible source of precession torque may come from the right hand camber of the wheels from A to C and the left hand camber from C to E.{Mr Elliott - Chief Engineer} This torque is also such as to straighten the wheels and is maximum about st B and D.{John DeLooze - Company Secretary} Probably this does not amount to much with ordinary caster offsets and with such small camber angles as we observe, the centre of camber side thrust is close to the kingpin line thus :- | ||