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).
Front wheel brakes, detailing axle twist under load and the resulting movement.
| Identifier | WestWitteringFiles\K\October1923\ Scan70 | |
| Date | 12th July 1923 | |
| R.R. 493A (40 H) (SL 12 12-7-23). J.H.D. EXPERIMENTAL REPORT. ORIGINAL Expl. No. 9940 REF: Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}/L/620.10.23. To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to CJ. c. to Da.{Bernard Day - Chassis Design} c. to HY.{Tom Haldenby - Plant Engineer} c. to Rs.{Sir Henry Royce's Secretary} S E C R E T. FRONT WHEEL BRAKES. We have ascertained that as the load is applied at the brake pedal, and in consequence the axle twists about its point of connection with the spring, the brakes tend to pull on. The bigger the pressure at the brake pedal the more the axle twists until the point is reached where the wheels are skidding. We have measured the actual movement of the compensator body when a given load is applied to the brake pedals and the car is pulled foward until the brake linings slide in the drums. We did this by attaching a long lever to the equaliser body so that the movement was very greatly magnified. Equivalent load on brake pedal. | Angular movement of equaliser body, this is angular movement of lever on the equaliser connected to the brake pedal by brake ropes, tending to put brakes on. --- | --- 94 lbs. | 2° 76 lbs. | 1.9° 57 lbs. | 1.6° 38 lbs. | 1.3° Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||