Originally Posted by
CKspeed
Actually the 1606L will zero the trip distance, trip time and averages all at once if you hold down the top right button for about 10 seconds. This may not be the case for a different model Sigma though. Agree that the o-rings are not the greatest. I need to adjust them before every ride.
On mine it is the upper left button. You have to hold it down for several seconds but it will flash "All Reset" and then it will reset.