Analysis of suspension 'dither' and bounce issues comparing different car bodies and springs.
| Identifier | ExFiles\Box 47\1\ Scan078 | |
| Date | 8th September 1921 | |
| - 4 - [STAMP: RECEIVED 8 SEP 1921] [Handwritten: aH] we have so far noted and which are possible in this action:- (1) Of the three cars tried in May, the two cars which 'dither' were fitted with Cockshoot bodies and overhung the rear of the chassis, whereas the other car which was alright in this respect was a Hooper type and did not overhang the rear of the chassis. (2) Comparatively, the rear springs of the 'dither' cars were weaker than the other and had a slower period of bounce. (3) The Buick car had a much higher period and was fitted with cantilever springs, the swivel pin being out of centre of the spring, which allowed the rear axle to go well to the rear of the car and the rear seats well forward. (4) Varying tyre pressures and varying friction of the shock absorbers did not cure the trouble. (5) The bodies which suffered from 'dithers' were non-boomers and the bodies themselves appeared to be rather flexible and non-rigid,whereas the car which did not suffer from 'dithers' was inclined to boom and felt a much more rigid body. When riding in 5-PK one had the feeling that one was riding on a fairly rigid mass supported on springs which were working satisfactorily and absorbed such jars as were conveyed to it through the shock absorbers. On the contrary on the other two cars, one has the feeling that one is riding on a flexible mass, which when struck with a blow sets up a shiver. This feature requires carefully testing out as it may be that the tendency for flexible mounting and non-booming bodies may be aggravating this trouble. (Sgd). Hm. {Capt. W. Hallam - Head Repairs} EP. {G. Eric Platford - Chief Quality Engineer} | ||
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).