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).
Procedure for measuring suspension friction and calculating the front wheel slip angle.
| Identifier | ExFiles\Box 170\3\ img079 | |
| Date | 21th May 1936 guessed | |
| 4 The car is driven to the flat plate and the transit sighted on the mark on the center post. If the post is on the right of the car as shown the car is rolled over to the left as far as it will stick and the corresponding altitude reading on the transit is taken as zero for right hand turns. Similarly a zero reading is obtained for left hand turns. The difference between these indicates the friction of the suspension. The readings of the horizontal scale on the transit increased by an angle which is approximately d/R in radians, represents the angle of the center-line of the car relative to its true "Ackermann" position. This is roughly speaking the slip angle of the rear wheels, and is so regarded in our tests. The indicated mean steering angle plus the above center line angle minus the angle subtended by the wheelbase, approx. l/R in radians. or - (Front wheel angle) + (transit reading) - (l-d)/R is the slip angle of the front wheels. | ||