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 S.A.E. standards for balloon tires and rims for passenger cars.
| Identifier | ExFiles\Box 17\7\ Scan054 | |
| Date | 4th December 1929 | |
| Revision approved by the Tire and Rim Division Dec. 4, 1929, for submission to Standards Committee meeting on Jan. 20, 1930 BALLOON TIRES AND RIMS for Passenger-Cars S.A.E. Standard | Rim Diam. | 4.75 | 5.00 | 5.25 | 5.50 | 6.00 | 6.50 | 7.00 | |---|---|---|---|---|---|---|---| | 18 | | | 5.25-18 | 5.50-18 | 6.00-18 | 6.50-18 | 7.00-18 | | 19 | 4.75-19 | 5.00-19 | 5.25-19 | 5.50-19 | 6.00-19 | 6.50-19 | 7.00-19 | | 20 | | | | | 6.00-20 | 6.50-20 | 7.00-20 | | 21 | | | | | | | | Flat base | Recommended Rim Section Width, In. | 2.75 | 4"(2.69) | 4"(2.69) | 4"(2.69) | 4½" (3.12) | 4½" (3.12) | 5" (3.75) | | Max. Tire Width on Rim Used | 5.05 | 5.15 | 5.35 | 5.60 | 5.95 | 6.40 | 6.90 | Drop Center | Recommended Rim Section Width, In. | 3.00 | | | | | | 4.00 | | Max. Tire Width on Rim Used | 5.20 | | | | | | 6.90 | | ||