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).
Weight distribution and steering effects of mounting spare wheels at the rear of cars, referencing a specific case for H.R.H. The Prince of Wales.
| Identifier | ExFiles\Box 13\5\ Spare05-page075 | |
| Date | 26th November 1939 | |
| HS.{Lord Ernest Hives - Chair} FROM DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} X7600 DA{Bernard Day - Chassis Design}/EV{Ivan Evernden - coachwork}4/M26.11.39. Copy to SG.{Arthur F. Sidgreaves - MD} R.{Sir Henry Royce} re. WEIGHT AT BACK OF CARS. X.7600 X.7840. X.4521. As you are aware, H.R.H. The Prince of Wales is carrying two spare wheels aft of the rear cross tube when touring on the continent: one only will be carried when in England, the other being left in the Garage. We persuaded him to do this rather then let him have the original design of two spare wheels permanently carried at the side, because we believed we were carrying out Mr. Royce's instructions to get all the weight at the back that we could. We note that in your reply to our query you see no objection to this, but hope that it will not happen too often. This is not frightfully convincing and has left an element of doubt in several quarters. Since the Prince of Wales has had this fitted we are taking it for granted that there will be at least one duplicate order. We would be glad if you could give us some experimental data as to the effect on the steering which the placing of the two wheels aft of the rear cross tube would have. About 1% of our output will have, and is suitable for, the dual wheel carrier as on 18-EX. A similar body to 18-EX, but with a division and one auxiliary seat facing sideways, is a far more saleable proposition. In order to get a trunk at the back we need to move the spare wheels aft of the rear cross tube. We would point out that it would not be advisable to carry out your tests on 18-EX, because to compensate for the removal of the two spare wheels a distance of 8" to the rear, the body at the centre is increased in weight by at least 2 cwts., being the addition of a dropping division and auxiliary seats. We have examined this theoretically and are inclined to think that the two cancel each other out. From the point of view of riding comfort you have already demonstrated that the further back behind the rear axle the weight is carried, the more effective it is, and the more like the 20HP. Phantom 2. becomes. DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} | ||