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 spare springs for the 25-EX U.S.A. model and 20 HP front springs.
| Identifier | ExFiles\Box 106\1\ scan0204 | |
| Date | 27th October 1930 | |
| To Hs.{Lord Ernest Hives - Chair} From Rn.{Mr Robinson} X 5410 Rm.{William Robotham - Chief Engineer}1/MJ.27.10.30. SPARE SPRINGS FOR 25-EX. U.S.A. X. 7410. X. 5410. FRONTS 40/50. These springs give .250 positive camber at 1100 lbs. load and having 5.5" pos. camber, give an initial deflection of 5.25". These figures are with the two leaves/spring removed. REAR 40/50. 9.75" Pos. Camber. These springs give flat camber under 1270 lbs. which means that on 25-EX. they will give 4.6" buffer clearance with the car empty. Four passengers drop the car 1.250 making clearance 3.400" at which clearance the total rear spring deflection is 10.5" against the standard 8.25" i.e. 27½% greater. 20 HP. FRONT. Free camber 5.00". Loaded 1.00 To Buffer 1.950 Effective decrease in rating over Standard 77.67%. Standard deflection 2.250". Altered " 4.00". Rm.{William Robotham - Chief Engineer} | ||