sentences:  This was later revised by the official time-keepers at the TT Grandstand to 99.97 mph.The 1957 Senior TT race was led by Bob McIntyre riding for Gilera and he beat the overall lap-record from a standing start in 22 minutes and 38.4 seconds at an average speed of 99.99 mph and was 0.6 seconds faster than the lap record set by Geoff Duke in the 1955 Senior TT Race.The main rival for winning the Senior TT race is John Surtees riding for MV Agusta who posts a time of 23 minutes and 17.4 seconds an average speed of 97.20 mph on the first lap.