Speedo and Odometer Calibration Chart by Darryl Patrak


Darryl posted this one the Yahoo EN500 forum and I thought it would go good here, as several have emailed asking the same question about how to calibrate, or at least compare "real" speed versus "indicated" speed! It is simple, IF you already know it, but... well if not, here it is. Thanks Darryl, once again!


CALIBRATE YOUR SPEEDOMETER in a mile or so using a straight flat road with mile markers, and a watch with a second counter. (be careful riding if you use a stopwatch!!

(Pay attention to the riding FIRST! - Paul)

Establish a steady speed. Carefully note the second counter as you pass a mile marker. HOLD SPEED AS STEADY AS YOU CAN!

Note the second counter as you pass the next mile marker.
Subtract to find the elapsed seconds to go one mile.


80 seconds = 40mph

72 seconds = 50mph

65 seconds = 55mph

64 seconds = 56mph

63 seconds = 57mph

62 seconds = 58mph

61 seconds = 59mph

60 seconds = 60mph

59 seconds = 61mph

58 seconds = 62mph

57 seconds = 63mph

56 seconds = 64mph

55 seconds = 65mph

50 seconds = 72mph

48 seconds = 75mph

45 seconds = 80mph

Or IN GENERAL, 3600 divided by seconds = mph

Baby took 46 seconds at indicated 83 for actual 78mph.
Redwing takes 48 seconds (75mph) at indicated 80.

CALIBRATE YOUR ODOMETER on a long stretch of highway with mile markers. The longer, the better. Pick a real easy mile marker number to remember. Stop at the marker. Reset your trip meter. Ride as far as you wish, and stop at a convenient mile marker. Subtract the first marker from the current (or the reverse, depends on which way you are going relative to mile markers.)