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).
Modified methods for calculating the springing on 40/50 HP chassis concerning rear seats, passenger numbers, and luggage weight.
| Identifier | ExFiles\Box 67a\1\ scan0244 | |
| Date | 6th September 1926 | |
| 48410 9-9/26 H/De Whar. C. HS.{Lord Ernest Hives - Chair} BY19/H.{Arthur M. Hanbury - Head Complaints} 6.9.26. ---------------- RE SPRINGING OF 40/50 HP. CHASSIS IN RELATION TO R AR SEATS. ---------------------------------------------------------------- Referring to FS{F. Steele}4/JP. 31.8.26. some six months ago, or slightly more, we modified our method of dealing with the estimated body weights and passenger weights for the phantom chassis. Prior to that date we were accepting the figures given by the coachbuilders for their passengers and luggage, but as a result of a certain percentage of complaints in regard to springing, the matter was investigated, and it was found by Sales that the coachbuilders did not find out from the customer the number of passengers he was carrying, but merely quoted the capacity of the body for seats. Under the old scheme, it was possible to spring a chassis for seven passenger, and 2 cwt. of luggage. Under the new scheme we never spring for more than four passengers and 1 cwt. of luggage. I do not wish the foregoing to be understood as meaning that we made no allowance but merely sprung for full loads. As a matter of fact after taking the full weight on the rear springs, body, passengers and luggage, we only used 70% of this figure as the basis for our springs. This should, and did, give quite a generous allowance, but in view of the demand for still lighter springing, we modified our methods as follows:- a/- If a range of weights was given to represent body, namely, 10 to 12 cwt, we invariably use the lower figure. b/- We never spring for more than four passengers, whatever the seating capacity of the car may be, and in a great many cases do not spring for more than three. c/- We only include 1 cwt. luggage. d/- We still take only 70% of the load arrived at as above, on the rear springs, as the basis for our spring calculation. There is one other point, however, we increase the strength of the springs for Continental work by 5%. | ||