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).
Test results for 5.50/18 India Speed Special tyres under specific load and speed conditions.
| Identifier | ExFiles\Box 29\4\ Scan202 | |
| Date | 4th July 1934 | |
| 4th July, 1934. TESTS ON 5.50/18 INDIA SPEED SPECIAL. Load - 9 cwts. Run at 63 m.p.h. for 30 minutes. Room Temperature - 80º F.{Mr Friese} Starting Pressure. Final Pressure. Increase in Pressure. % Increase. Final Temp. of Tread. 20 lbs. 30 lbs. 10 lbs. 50%. 172º F.{Mr Friese} 22 " 31 " 9 " 41%. 169º F.{Mr Friese} 25 " 34 " 9 " 36%. 165º F.{Mr Friese} 28 " 36 " 8 " 28.5%. 158º F.{Mr Friese} 30 " 38 " 8 " 26.5%. 158º F.{Mr Friese} 32 " 40 " 8 " 25%. 158º F.{Mr Friese} 35 " 44 " 9 " 25.7%. 152º F.{Mr Friese} =====oOo===== | ||