there's no calculation that you can do to determine how off the speedo is. get a gps and find out. or better yet, just do the speed limit - you're pretty much guaranteed to never actually be speeding.tomkalina said:I'm running Z6's with about 2K on them, evenly worn ; 33 psi front, 36 psi rear.
Measure the elapsed time for a mile at 60 MPH (indicated).stranger said:"there's no calculation that you can do to determine how off the speedo is..."
this assumes that you need to operate a stopwatch while riding to get an accurate start/stop time and watch the speedo for the entire riding time. not the safest.nc_sv650 said:Measure the elapsed time for a mile at 60 MPH (indicated).
3600 (D/T) = R, where D equals 1 mile, time is your observed time in seconds and R is your actual speed in MPH.
(60-R)/60 = % speedo error.
indicated speed + (indicated speed * % speedo error) = actual speed
example: A mile in 63 sec is ~57 MPH, a 5% speedo error. 127 MPH (indicated) would then be ~120 MPH (actual).