/fa/ - Fashion

>>13832201
Tuning fork watches use an index wheel system to advance the geartrain. The index wheel teeth are very (very) small and the index wheel is an easily damaged part of the watch. When the wheel is being ratcheted forward by the tuning fork and finger pawls, it works pretty well. But imagine if you tried to turn the index wheel backwards. The fingers wouldn't ratchet, and you end up shearing off the teeth. This is how index wheels, the most commonly damaged (and completely irreparable) parts of a tuning fork watch, are damaged.

When you set a watch, the minute and hour hands turn independently of the second hand because of the tension in the cannon pinion. It slips against the rest of the geartrain. But if the tension is not absolutely perfectly adjusted, this will put some tension on the rest of the geartrain. In traditional mechanical watches this can cause back hacking, or even cause the second hand to run in reverse. This doesn't cause any damage - it's just turning the escape wheel backwards, and that wheel can easily take it. But in a tuning fork watch, it turns the index wheel backwards, which causes the aforementioned damage.

Don't do it. It's a pain - especially on day/date models with no quickset - but it's not worth it.