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).
Shock absorber testing, comparing different settings and types.
| Identifier | ExFiles\Box 28\1\ Scan075 | |
| Date | 30th April 1926 | |
| Oy2-E-43026 -2- April 30th, 1926 The effectiveness of the delay-action valve is shown by our being able to use at the rear, a 100 lb. spring giving 315 lbs. on the strap, whereas with the two valve instrument we could only use a 40 lb. spring giving 126 lbs. on the strap. Front Installation. The use of shock absorber setting at the front giving a combined strap pull for the two instruments equal to nearly 5 times the weight of the axle was obviously wrong. Comparing with our friction shock absorber setting, we have on the Lovejoys 450 lbs. on down stroke only, on R.R. set for 5" tires, 35 lbs. on both strokes, on R.R. set for 6-3/4" tires, 80 lbs. on both strokes, 75 lbs. on the R.R. gives a definite stiffening effect on the riding. The following tests were made on 69-JC 1st. Fitted with R.R. shock absorbers with new leathers oiled only superficially (leathers soaked in oil will not give the load). Set at 80 lbs. Riding very good. Slight pitching in rear seat. 2nd. R.R. shock absorbers slacked off completely. Riding fair at moderate speeds. Bad pitching above 35 m.p.h. objectionably chiefly in rear seat. 3rd. Lovejoys substituted. 100 lb. springs. Bad pitching in rear seat all speeds. 4th. Lovejoys. 40 lbs springs. Good riding at all speeds. Pitching slight even in rear. (180 lbs. maximum load on strap.) 5th. Lovejoys. Springs packed out .093 with three 1/32 washers giving 25 lbs. on valve (112 lbs. on strap). Riding too free. Bad pitching at all speeds. 6th. Lovejoys. 2 washers removed, giving 35 lbs. on valve (157 lbs. on strap equivalent to 75 lbs. setting on R.R. friction type). Riding good all speeds. Pitching not objectionable in rear seat at any speed. This is the best riding we have ever had with front Lovejoys. It is too early yet to say whether it is equal to a standard job. | ||