I have no idea, as I said it really depends on the bike setup....And what gearing it has, and if it has had the speedo re calibrated, and if so how accurate that calibration is...
Every tooth makes a difference in what the speedo will read...Even your tire wear affects your speedos accuracy, as the diameter of the wheel makes a difference in the calculation of revolutions=speed
When it comes to things like this you really need a radar gun to get accurate IMO, even GPS isnt that accurate depending on what device your using...