I have a drive roll that needs to turn 500Ftm min.. It now turns at 420Ft.min.
The drive shaft FPM is 61
The drive shaft RPM is 120
The drive sprocket has 24 tooth
The driven shaft FPM is 120
The driven shaft RPM is 245
The driven sprocket is a 10 tooth
:confused:

It is 28 to 10 tooth.. quit second guessing yourself