What is the difference between Sellita caliber SW200 and SW200-1?
On August 4, 2013 Sellita published a document about the evolution of the caliber SW200 automatic mechanism. According to watch movement manufacturer, the goal for the change is to:
Minimize wear and tear of the wheels in the automatic chain changing the tooth profile.
According to the document, the changes to the -1 variation include making modifications to the following components of the movement:
Axis of reduction wheel (1481)
Axis and wheel of ratchet wheel driving wheel (1482)
Ratchet wheel (415)
According to the documentation, other than the three components pictured above, all other parts of the caliber SW200 are interchangeable with the SW200-1. When performing maintenance or repair, these three components should be changed together to maintain functionality of the gear chain.
The gears on the original SW200 are following normal standards, however, Sellita found that each individual tooth has “slim geometry” and have been known to get damaged due to strong shocks to the watch. The new gear design provides power transmission equal to the SW200, but they strengthened the tooth geometry to reduce the risk of damage from strong shock.
The change from SW200 to SW200-1:
The change of version is part of our ongoing improvement strategy to optimize the performance of our calibers. -Sellita
Have you you noticed any differences with the SW200 and SW200-1 in everyday use? Please comment below.