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).
Extract from a report on chassis No. 7-CA concerning its poor road-holding capabilities.
| Identifier | ExFiles\Box 183\M22\ img012 | |
| Date | 9th September 1916 | |
| R.R. 295 A (400 T). (S.C. &C. 19-2-16) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1346. 7CA & 49GB R14/W9916. September 9th 1916. EXTRACT FROM RE CHASSIS NO 7-CA. X.424 HOLDING THE ROAD. The springing of this car was most supple, and the rear springs very free from friction, owing to thick plates and much grease. On the smooth roads free from small undulations or pot holes in the road, the rear wheels held the road satisfactorily, but when the road surface had small undulations or pot holes and bumps, the car felt very dangerous if driven over 40 miles an hour. It appeared very much worse than 49-GB, but it might have been the peculiar condition of the road, or perhaps hardness of tyres. I have left this to the last as really being the most serious problem to attack. It is primarily caused by the weight of the wheels and back axle, viz., the unsprung weight compared with the sprung weight of the body and rear portion of the frame. It is evidently also dependent upon the ratings of the road springs and the damping friction between the frame and the axle. I telegraphed from Wisbech that another car should be fitted up similarly and every effort to be made to improve the ability of the car to hold the road. It will be remembered that this car has been fitted with larger wheels, which of course are heavy, and would rather increase the tendency for the wheels to leave the road. | ||