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).
The performance and limitations of a Dunlop Jack for Balloon Tyres.
| Identifier | ExFiles\Box 48\1\ Scan010 | |
| Date | 1st December 1924 | |
| +4124. Dec. 1924. DUNLOP JACK FOR BALLOON TYRES. X.4B65 X.4124 Lowest position of Jack - HEIGHT. At present. Previously. 5 11/16" 6 3/16" 1st. stage of Jack. 9 9/16" 10 7/16" 2nd. stage " " 11 5/8" 13 1/8" ------------------- Front (axle) Height from floor. Rear (spring clips). height from floor Taking wheel off - 11 5/8" Taking wheel off - 11 5/8" inflated. Can just inflated. manage to get wheel on and off with full One bare rim 6" limit of jack (11 5/8") Both bare rims. 5 5/8" but not O.K. ------------------- As above the maximum lift is not enough to allow of taking an inflated tyre off the front - the smallest compass of the jack on the other hand is too high to allow of a bare rim to be taken off the rear (one bare rim already being on the opposite wheel) by 5/16". | ||