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).
Analysis of weights and dimensions for various 40/50 brake drum configurations and assemblies.
| Identifier | ExFiles\Box 120\1\ scan0053 | |
| Date | 8th November 1931 guessed | |
| 40/50 BRAKE DRUM COMPLETE WEIGHT. WEIGHT OF COMPLETE ASSEMBLY ON HUB SHELL. Lake and Elliott Solid Drums Complete. 52 lbs. 12 ozs. High Carbon Steel Complete. 53 lbs. 8 ozs. 40 Stiffer Standard Drum G.79012 complete 49 lbs. Ex. Standard Drum G.76123. Complete. 44 lbs. 6 ozs. 40/50 FRONT DRUMS COMPLETE. High Carbon Steel. 33 lbs. 12 ozs. Standard. G.78823. 27 lbs. 7 ozs. Total increase in car weight due to ribbed drums. Front 12 lbs. 10 ozs. Rear. 7 lbs. 8 ozs. 20 lbs. 2 ozs. FRONT DRUM ANALYSIS. ELIMINATING HUBSHELL Weight of end plate - 8 lbs. 10 ozs. R.R. C.I. solid drum - 10 lb. 8 ozs. Studs and nuts - 4 ozs. Width of wearing surface. Depth top of rib to wearing surface. Thickness of liner. Total weight Hispano 2.5" .800 .180 16 lbs. 9 ozs. R.R. 2.00" .750 19 lbs | ||