There are 2 cogwheels which should be renewed to solve problems with the Odometer:- 15 teeth cogwheel (Skandix 1062110)- 25 teeth (Skandix 1021067) or 26 teeth (Skandix 1062109) at the Speedo.Both versions may occur: The 25 teeth cogwheel is the most common in Europa the 26 teeth cogwheel is the most common in North America