This can prove somewhat difficult for non-watchmakers. The most reliable indicator is the amplitude of the balance wheel. However, this is basically only detectable using measuring equipment and is thus an important role played by the watchmaker. A reduction in amplitude is sometimes accompanied by a change in the movement's speed. The watch speed can start to vary, making it either too fast or too slow. This is a sure sign for non-watchmakers that something in the movement has changed.

It is not unusual for movements to keep reliable time for much more than five years. Personal wearing habits, environmental influences and many other factors each have an impact on the movement. We may advise against a premature service under certain conditions if it is deemed unnecessary. Our intention is to draw attention to the possibility of wear. A watch movement bears a basic similarity to a combustion engine: insufficient oil lubrication over an extended period can bear the risk of engine damage whose repair would cost disproportionately more than a small inspection and regular oil changes. The main concern is to prevent secondary damage.