trailtech gps. want to see pics of it? then go here.....[/quote]

FYI, that's not a GPS. A GPS is a device that uses a satellite to track your progress and is typically very very accurate for measuring speed. What you have is a Trailtech Speedo (I have one as well) and is only as accurate as your calculatoin for wheel circumference. And if you ride on pavement frequently, that would indicate that your tires wear faster than normal, and therefore are getting smaller so without changing the circumference programmed into your trailtech you would actually seem to be going faster than you really are. A smaller circle rotating the same number of times appears to be rolling faster.