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).
Modifications to rear wheel carriers to accommodate larger 7-inch section tyres and the resulting impact on coachwork.
| Identifier | WestWitteringFiles\T\March1929-December1929\ Scan306 | |
| Date | 10th December 1929 | |
| [STAMP] ORIGINAL 7 [Handwritten] x 7830 x 7600 BY.{R.W. Bailey - Chief Engineer} FROM DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} (BY.{R.W. Bailey - Chief Engineer} is struck through) DA{Bernard Day - Chassis Design}/EV{Ivan Evernden - coachwork}4/M10.12.29. C. to -SC- (SC is struck through) HS.{Lord Ernest Hives - Chair} P. 2. REAR WHEEL CARRIERS. While we retain the 21" rims it would appear as though we must raise the rear wheel in order to permit of India, and Goodyear, or Dunlop, tyres of 7" section being fitted to all cars we produce, as soon as possible. Even should 7" section tyres not be ordered at first they will certainly be fitted subsequently in many cases. In order to cater for this, and for spare wheel covers, we agree to raise the centre from 7.250 to 8.750 above the level top of the frame. Since this may affect the coachwork of maximum bodies we think that the coachbuilders should be given ample notice of the change. What happens about the increased width of section? Ought we not to move the wheel forward to cater for 7" section, or is there enough room already. From our reading of the drawings it does not appear to be so. We are testing, and hope to standardise, the Dunlop Reinforced Silent Tread of 7" on a 20" rim, in which case we can cater for the corresponding India and Goodyear covers by dropping the centre of the wheel down to 7.750 above the centreline of the chassis frame. This is shewn on N. scheme 2993. - the experimental Pullmanlimousine. We would be glad if Derby would set out the carrier as indicated on this drawing, and also the dual carrier. [STAMP] RECEIVED ... 11 DEC 1929 DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} | ||