Brake pedal feel, leverage ratios, and clearance issues on the Phantom II.
| Identifier | ExFiles\Box 12\5\ 05-page140 | |
| Date | 30th October 1929 | |
| Hs {Lord Ernest Hives - Chair} /From Da. {Bernard Day - Chassis Design} c. to By. {R.W. Bailey - Chief Engineer} EP. {G. Eric Platford - Chief Quality Engineer} x7420 Da. {Bernard Day - Chassis Design} 1/30.10.29. X.7420 X.7350 PHANTOM 11 BRAKES. With reference to EP {G. Eric Platford - Chief Quality Engineer} 5/24.10.29., the phenomenon of the pedal coming down on to the boards had we thought been improved, first by putting the centre of the levers on the axle in the centre of the rear spring leaf, and secondly by reducing the amount of direct braking. As it stands now there does not appear to be any reason for it being more spongy than Phantom. The shafts are as stiff, or stiffer, and because of the greater ratio on the back axle the torque on all the shafts until the back axle is reached has been reduced. As regards the excessive clearance asked for, namely, 1.5" at the end of the axle lever, this is difficult to understand. It will naturally be more than Phantom because the leverage on the axle is more, but only in the ratio of 16 to 14. Any pumping that there is does not tend, from our setting out., to pull on the brakes, and therefore, should not be the cause of the required clearance. Furthermore, the effect of the pumping is reduced by the increased axle leverage. If a finer adjustment is required we think we can provide this, but we should like some more information as to the cause of this big clearance before doing anything. Da. {Bernard Day - Chassis Design} | ||
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).