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).
Specification tables for low rating springs for 40/50 and 20 HP models.
| Identifier | WestWitteringFiles\W\May1931-August1931\ Scan006 | |
| Date | 12th May 1931 guessed | |
| PARTICULARS OF LOW RATING SPRINGS. | | Length. | Width. | Top Leaf Thickness. | Initial Deflection. | Max. Bump Deflection. | |-------------|---------|--------|---------------------|---------------------|-----------------------| | 40/50 Front | 45.0" | 2.00" | .257" | 4.5" | 6.250" | | 40/50 Rear | 66" | 2.5" | .265" | 10.25" | 14.1" | | 20 H.P. Front| 38" | 1.75" | .222 | 4.0" | 6.5" | | 20 H.P. Rear | 56.0" | 2.25" | .264" | 6.4" | 10.0" | | | Free Camber. | Loaded Camber. | Buffer Clnce. | |-------------|--------------|----------------|---------------| | 40/50 Front | 4.5" Pos. | Flat. | 1.750" | | 40/50 Rear | 10.25" | Flat. | 3.850" | | 20 H.P. Front| 4.5" | .5" Pos. | 2.45" | | 20 H.P. Rear | 5.9" | .5" Neg. | 3.625" | | ||