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 on internal spring friction and rear spring ratings.
| Identifier | WestWitteringFiles\S\September1928-October1928\ Scan033 | |
| Date | 6th September 1928 guessed | |
| contd :- -4- (d) That the weaker front springs make a marked difference to the riding with tyres at standard pressures. (e) That this difference is somewhat less marked with reduced tyre pressures and front shock absorbers disconnected. INTERNAL SPRING FRICTION. We removed the original rear springs and measured their internal friction. We replaced them by springs of similar poundage, freshly greased and cadmium plated, which we had previously tried for internal friction. We attach curves of the relative internal friction. of We the two pairs of springs. Our results shewed an advantage for the freshly greased springs but not so great as we anticipated. We know, however, that the Repair Dept. get springs which have been in service five years or so, the internal friction of which must be very great as they can scarcely rock the car with the shock absorbers disconnected. We are waiting the opportunity to test a pair of such springs off a customers car. We are making out a separate report on internal spring friction and shall repeat our road test on rear spring internal friction and also make some comparative tests on front spring friction. REAR SPRING RATING. We fitted 1600 lbs. rear springs cadmium plated and freshly greased and compared them with the 2000 lbs. cadmium plated springs. The former gave 4" buffer clearance, the latter 2.5" buffer clearance. We compared these springs in the same conditions as tests 5, 6 and 7. The difference with hard tyres and shock absorbers was appreciable but no more than that produced contd:- | ||