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).
Specifications for varying spring stiffness and buffers on cars for different countries.
| Identifier | ExFiles\Box 54\3\ Scan150 | |
| Date | 3rd October 1924 | |
| - 3 - BY1/H.{Arthur M. Hanbury - Head Complaints} 3.10.24. For normal cars generally, that is, cars in this Country and Abroad was a spring 20% stiffer than the old standard, on the assumption that normally, cars for England would, generally speaking, do a fair amount of Continental work under modern conditions. The outline of how to earmark where the 12½% stiffer is to be fitted, and the 20%, given above, is to make R's attitude as plain as possible in actual quantities. In order to round the whole question of springing up, whilst the memo deals essential with front springs, it is necessary to make the following comments with reference to rear springs. For Continental Cars, the rear springs would, generally speaking, be 5% stiffer than standard. This will apply to all Countries except the following:- Spain. Portugal. Italy. Austria. Poland. Australia. New Zealand. For these Countries, rear springs 20% stiffer than standard will be fitted, and in order to keep the height of the chassis right, it should be noted that Mr.Booth has ordered springs stiffer in proportion to the requirements outlined here. Our present policy in regard to spring buffers is that these will be fitted of different depths for the varying stiffness of springs, that is, the 12½% spring will have one buffer, the 20% schemed above will have another buffer, and for the 20% stiffer rear springs for the special Countries a special buffer will also be fitted. The clearance between the buffer and the springs will continue to be in accordance with our previous practice so as to keep the stress in the springs to a certain limit. R.{Sir Henry Royce} has made suggestions to decrease the clearance between the buffer and the spring, but this is not being agreed to until it has Contd. | ||