Not too sure on the 50-100 mph thing. 60-130 mph is a standard and it's not just for fun. Many standards abroad are 100 - 200 km/h which is .....erhhh 60 - 130 mph
When doing 50-100 mph the times are too much dependant on gear ratios and even more when FFS is used or not. It doesn't really compare to HP figures....
But oh well...... crack on