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).
Brake performance issues on the Phantom II, specifically pedal feel, sponginess, and clearances.
| Identifier | WestWitteringFiles\T\March1929-December1929\ Scan232 | |
| Date | 30th October 1929 | |
| HS.{Lord Ernest Hives - Chair} FROM DA.{Bernard Day - Chassis Design} Copy to BY [struck through] EF. DA{Bernard Day - Chassis Design}1/M30.10.29. x74~0 x7350 [STAMP] ORIGINAL PHANTOM 11. BRAKES. With reference to EP{G. Eric Platford - Chief Quality Engineer}5/H241029., 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 rearspring 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} [Signature] | ||