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).
Tests comparing the relative merits of hydraulic and friction shock dampers for low-speed riding comfort.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan069 | |
| Date | 28th April 1926 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c.c. to EJ. RG.{Mr Rowledge} c.c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c.c. to EY. Wor.{Arthur Wormald - General Works Manager} c.c. to Na.{Mr Nadin} ORIGINAL. Hs{Lord Ernest Hives - Chair}/Rml/LG28.4.26. Handwritten: X4426 X8410 8235 SUSPENSION. We have carried out tests in confirmation of our report Hs{Lord Ernest Hives - Chair}/Rml/LG24.4.26. We find that the results previously given seem to represent the facts with regard to the relative merits of the hydraulic and friction shock dampers with regard to low speed riding comfort. We have been carrying out tests comparing these hydraulic dampers with Hartfords at the standard setting of 40 lbs. at high speeds. So far our impression is that graduated hydraulic damping on the rear would produce the best results. By this we mean that we feel we want much less than 60 lbs. damping at 20 - 30 m.p.h. on a main road, but much more than 60 lbs. damping when approaching maximum bump or maximum rebound. The Lovejoy shock damper does this in a minor degree being a two-stage operation. The Lancia is more pronounced, the hydraulic buffer on a big gun is completely graduated in action. We believe that we can give our present dampers a certain amount of free movement in the centre by means of a graduated longitudinal slot in the chamber giving a variable leak. We cannot, however, get the high poundage we require at the ends of the stroke as the design of the damper limits this to 85 lbs. at the end of the long lever on the rear. contd :- | ||