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).
Investigations into radiator shimmy, detailing experiments with frame stiffening, axle changes, and wheel sizes.
| Identifier | ExFiles\Box 14\8\ Scan210 | |
| Date | 29th January 1930 | |
| R.{Sir Henry Royce} FROM DA.{Bernard Day - Chassis Design} (held up.) X7380 DAL/M29.1.30. C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} C. to HS.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} E.{Mr Elliott - Chief Engineer} RADIATOR SHIMMY. X.457 X.7250 X.7380 The lines on which we are working on this problem are, stiffening the front end of the frame by a 4" tubular cross member temporarily fitted immediately behind the dumb irons. I have been to Derby twice but the experimental pieces were not quite ready. Should this additional stiffness prove beneficial it is intended to increase the flexibility of the engine mounting until a satisfactory degree of smoothness has been attained, still more stiffness being added to the frame if necessary. As a permanent fitting for early adoption it seems possible to put a cross in the frame between the radiator cross member and the tubular front cross member, which, if combined with the use of an apron, which is growing in popularity, would alter the front appearance of the car. We are preparing a design for this. Further stiffness in the future could be obtained by the deeper side channels proposed by Mr. Royce, and now partly schemed, but held up awaiting some confirmation that stiffness is what is required. The experiment is being made of changing the axle from Phantom 2. to Phantom 1. and also from one Phantom 2. to another. Also of altering the spring height by pads on the axle. In most of these cases the geometry of the steering is affected so as it seems to us, modifying the effect of the axle movements on the steering wheel. The tugging at the wheel which accompanies the radiator shimmy seems to be the worst part of it. It was demonstrated while I was in Derby that changing the wheels from 21" to 20" rims markedly improved a bad shimmker. There are many standard Phantom 2. cars which are perfectly dead as far as the radiator is concerned. DA.{Bernard Day - Chassis Design} | ||