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).
Report comparing the riding comfort of 'Fort M.A.2' and 'Fort '90'' tyres using blindfold and accelerometer tests.
| Identifier | ExFiles\Box 157\1\ scan0175 | |
| Date | 7th February 1935 | |
| 7.2.35. RIDING COMFORT. FORT M.A.2 V.{VIENNA} FORT '90'. Two Tests have been carried out in 6.00/19 Size. 1. Blindfold Test. For this, the driver and four observers made two identical journeys in complete ignorance of the type of tyre with which the car was equipped. These were called Set 1 and Set 2 until statements had been made in secret. The inflation pressure was 36 lbs./sq.inch in each case. The statements disclosed the following:- Driver - No difference between Set 1 and Set 2; although window rattles were more pronounced with Set 2. All four - Set 2 slightly more comfortable than Set 1. Observers. (Separate comments made in writing). Set 1 = M.A.2 Pattern. Set 2 = '90' Pattern. 2. Accelerometer Test. Cambridge accelerometer carried on the floor of the car. Two tests on each of the two sets of tyres in each direction of the road. One stretch of road (about 30 yds.) used for North Easterly, and adjoining stretch used for South Westerly runs. The attached records from the instrument show the '90' pattern to be a little more comfortable in the S.W. run and very little difference between the sets in the N.E. trip. The general inference is that there is very little difference; but that the '90' pattern is certainly not inferior to the M.A.2. | ||