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).
Noise measurement tests for 'Speed Special' tyres at different speeds and inflation pressures.
Identifier | ExFiles\Box 30\5\ Scan141 | |
Date | 23th October 1935 guessed | |
MEASUREMENT OF NOISE PRODUCED BY 5.50/18 SPEED SPECIAL. FIGURES ARE IN DECIBELS (UNITS OF NOISE) Test at 30 lbs. inflation pressure with 10 cwts. load. Speed Miles per hour. Old Speed Special. 1st Mould Change. 2nd Mould Change. 15 67 66 65 20 71 69 68 25 73 70 70 30 75 74 73 35 76 75 74 45 78 76 77 50 78 78 78 Test at 25 lbs. inflation pressure with 10 cwt. load. Speed Miles per hour. Old Speed Special. 1st Mould Change. 2nd Mould Change. General Noise in room No tyre running. 15 68 66 66 60 20 72 69 68 64 25 73 71 70 66 30 75 74 74 68 35 76 76 74 72 45 78 77 76 74 50 78 78 78 74 ====Ooo==== | ||