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 detailing the dimensions and weights of various tyres at recommended pressure.
| Identifier | ExFiles\Box 29\4\ Scan248 | |
| Date | 12th December 1934 | |
| 12th December, 1934. Dimensions taken at maximum recommended load for section and corresponding recommended pressure as shown in our inflation tables. Rim. Tyre & Tube Weight. X Section Inflated. Eff. Rad. O.D. Inflated. Rolling Radius. 6.00/18 3.25/18 29.1 lbs. 6.32" 14.35" 30.76" 14.64" Super Special. 4.34 " 5.50/19 3.25/19 27.5 lbs. 6.07" 14.65" 31.36" 14.94" Super Special. 4.04 " 6.00/19 3.62/19 30.44 lbs. 6.51" 14.92" 32.00" 15.22" Super Special. 4.53 " 6.00/20 3.62/20 31.86 lbs. 6.51" 15.42" 33.00" 15.73" Super Special. 4.71 " 5.50/18 3.25/18 26.52 lbs. 6.09" 14.12" 30.28" 14.40" Speed Special. 3.88 " =====oOo===== | ||