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).
Comparative analysis of various shock absorber and spring types for different car models.
| Identifier | ExFiles\Box 28\1\ Scan035 | |
| Date | 24th September 1924 guessed | |
| -3- (7) Contd. For rough touring generally, we use 40 lb. springs without packing in 1st. stage. In extreme cases we fit 80Lb. springs in the rear on covered cars. For open touring cars, i.e. Roadster, 5 Passenger Phaeton, and 7 passenger Touring:- 1st. stage 40 Lbs. 2nd. stage 80 Lbs. As compared with other types, we have experience of the various "wrap-up" types, Gabriel, Star (now made by American Bosch) and Watson Stabilator. These collect mud, creak and stiffen the riding to an extent which makes it very much more like a Packard or Locomobile than a Rolls-Royce. The best is probably the Watson, the chief defect of which is creaking and grunting. The American built Houdaille we have tried and consider very much more fierce in its action, especially over potholes, than is good for either passengers or car. Also has 2 ball joints just where they are inaccessible and collect mud. The Hartford lever type with ball joint arm we broke up in very short time by a little rough riding, and consider too adjustable and stiffens riding of car. The Hartford scissors type we have not tried, but it rattles on the Marmon. We have now used the Lovejoys for a year and beyond pulling out of a few straps where the cramping nut had loosed up for lack of a lock washer, have not had an unsatisfactory one or any service work. In service and production we have now used about 400 pairs of Lovejoy shock absorbers. One interesting point is that due to the construction of with large valves the shock absorbers do not stiffen up noticeably in cold weather as happens with the orifice type. The oil used has a setting point of I believe about 10 above zero, but no trouble has occurred at temperatures considerably lower than this. I imagine that what happens is that the oil gets very thick if it tends to put the shock absorbers out of commission rather than stiffen it up. | ||