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).
Comparison document outlining the weight differences between straight-sided and beaded edge wheels for the Goshawk model.
| Identifier | ExFiles\Box 106\4\ scan0015 | |
| Date | 2nd February 1922 | |
| E.{Mr Elliott - Chief Engineer} from Hs.{Lord Ernest Hives - Chair} c. to BJ. c. to Roy.{Sir Henry Royce} X3599 X3601 Hs{Lord Ernest Hives - Chair}1/LG24. 2. 22. GOSHAWK - STRAIGHT-SIDED AND BEADED WHEELS. We do not consider the comparison between a 32 X 4½ straight-sided rim compared with a 820 X 120 beaded rim, shows the true difference between straight-sided and beaded edge rims. If we make a comparison of our 40/50 wheels, in which case the diameters of the rims and tyres are very similar, the difference in weight between a 33 X 5 straight-sided wheel complete with tyre and tube compared with the latest 895 X 135 Magnum cord, is 5½ lbs. This weight is made up as follows:- Straight-sided. Wheel 43.0 lbs. Cover 36.0 " Tube 7.0 " Security bolts Band 1.0 " 87.0 " Beaded edge. 38.0 lbs. 35.25 " 7.0 " 1.25 " 81.5 " = difference 5.5 lbs. The 820 X 120 size of rim will most probably be obsolete in a short time. It would appear unwise for us to start off with this size. Hs.{Lord Ernest Hives - Chair} | ||