The LargeChange property sets the change in value that one click of the mouse outside of the slider makes. Let's say that the position of your thumb is at the beginning of the RadTrackBar (at position 0), the value of this property is 5 and you click on tick number 14. The thumb will reposition itself to tick number 5, following the step determined by the LargeChange property. However, if the LargeChange has value 0, the thumb will move to position 14. It is necessary to be added another property to control the step when changing the value when using the left/right buttons, e.g. SmallChange.