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).
Rating test results for engine foot rubbers supplied by Dunlops.
| Identifier | ExFiles\Box 14\5\ Scan043 | |
| Date | 3rd January 1929 | |
| 3.1.29. F.78114 ENGINE FOOT RUBBERS ) RATING TEST. Supplied by Dunlops 2.1.29. DEFLECTION INS. Load lbs. | 1Z | 2Z | 3Z | 4Z | 5Z | 6Z. 0 100 | .036 | .035 | .036 | .038 | .036 | .039 200 | .062 | .060 | .061 | .065 | .060 | .065 300 | .086 | .085 | .084 | .088 | .083 | .087 400 | .105 | .104 | .103 | .107 | .102 | .106 500 | .119 | .120 | .118 | .122 | .118 | .122 600 | .132 | .135 | .132 | .136 | .131 | .135 700 | .137 | .137 | .144 | .147 | .143 | .146 800 | .158 | .159 | .155 | .159 | .155 | .159 900 | .170 | .170 | .167 | .170 | .166 | .170 There is a variation in free length of .008" and the shortest rubber is .038 over drg.size. Variation in deflection at 900 lbs. load .004". | ||