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).
Table of specifications for drive and cone seats on R.W. detachable wheels, separated by years 1912 and 1913.
| Identifier | ExFiles\Box 159\7\ scan0016 | |
| Date | 11th September 1912 guessed | |
| PARTICULARS OF DRIVE & CONE SEATS ON R W DETACHABLE WHEELS Type. | Maximum Angular Movement | Effective Driving Area. | Effective Driving Area X Mean Radius. | Area of Cone Seat (Hub & Shell) | Area of Cone Seat (Spoke Ring & Locknuts) | Area of Seating of Threads. Units: | Degrees. | Max. Sq CM | Min. Sq CM | Max. Sq CM x CM | Min. Sq CM x CM | Max. Sq CM | Min. Sq CM | Max. Sq CM | Min. Sq CM | Max. Sq CM | Min. Sq CM 1913. 42. | .362 | 35.3 | 28.4 | 107 | 87 | 35.2 | 34.1 | 22.1 | 20.2 | 19.1 | 15.2 52. | .302 | 41.4 | 33.4 | 148 | 119 | 40.5 | 39.2 | 25.0 | 22.9 | 22.6 | 18. 62. | .264 | 61.1 | 50.0 | 248 | 203 | 45.3 | 43.9 | 27.7 | 25.4 | 25.8 | 20.6 72. | .238 | 75.2 | 61.8 | 340 | 280 | 50. | 48.4 | 30.3 | 27.7 | 28.9 | 23.1 80. | .216 | 86.3 | 71.1 | 433 | 356 | 54.8 | 53.1 | 33. | 30.2 | 32. | 25.7 90. | .196 | 102.8 | 85.0 | 566 | 467 | 59.7 | 57.8 | 35.7 | 32.6 | 35.4 | 28.2 100. | .178 | 117.7 | 97.6 | 715 | 592 | 65.3 | 63.2 | 38.8 | 35.5 | 39.1 | 31.3 120 | .160 | 138.3 | 114.7 | 940 | 779 | 72.6 | 70.3 | 42.8 | 39.2 | 44. | 35.1 1912. 11. | .300 | 24.5 | 19.2 | 74.7 | 58.6 | 27.9 | 26.7 | 6.7 | 6.2 | 8.7 | 7.3 12. | .256 | 25.95 | 20.2 | 92.9 | 72.5 | 31.6 | 30.3 | 6.7 | 6.2 | 8.7 | 7.3 8. | .225 | 32.6 | 24.7 | 132.9 | 100.7 | 40. | 37.8 | 11.4 | 10.9 | 15.6 | 13.1 6. | .168 | 7.5 | 6.7 | 37.8 | 33.8 | 32.9 | 31.1 | 21.8 | 21.2 | 23.9 | 20. 9. | .157 | 42.5 | 31.7 | 248.5 | 185.4 | 61.2 | 58.6 | 21.8 | 21.2 | 23.9 | 20. 5. | .132 | 7.4 | 6.6 | 47.5 | 42.9 | 40.5 | 38.3 | 27.9 | 26.9 | 31.2 | 26.1 | ||