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).
Ratio of servo braking for front and rear brakes in relation to vehicle weight.
| Identifier | ExFiles\Box 5\3\ 03-page132 | |
| Date | 1st July 1934 | |
| contd :- -2- Incidentally in the instructions given in *Hsl/LG9.7.34. for testing the EAC.3. servo efficiency "it appears that the ratio of rod loads is expected "to come within the limits given on the diagram of "braking, which is in terms of servo torque". ------------ We should also like to point out that the proportion of servo braking which is sent to the front brakes will vary with the weight of the car, and will always become a greater proportion with the lighter car. For example, if we take the India distribution of braking as 25 direct braking, 25 to the rear and 25 to the front, that is, the ratio of front to back is 1 over 2, the ratio of the servo braking to the front and rear is 1 over 1. Taking a car of twice the weight, instead of 75 total units of braking being available, there are now 150., and keeping the distribution of braking the same, namely, front to rear as 1 over 2, then the total units to the rear are 100., the total units to the front are 50., and of the 100 to the rear 25 is direct braking, as on the lighter chassis. In this case it will be seen that the servo ratio front to back is 50/75. If this were carried still further, and a car of half the India weight were considered, the direct foot braking remaining 25., it would be seen that the whole of the servo must be sent to the front. DA.{Bernard Day - Chassis Design} MADE AT CROXLEY | ||