Swatch Sistem51 SUTB402

Timing Data

The accuracy of the Sistem51 is difficult to judge with the available data. Because the second hand does not hack, it is always out-of-step with the minute hand. It is therefore necessary to make a careful judgement of not just the second hand but also the minute hand.

This watch has shown quite variable accuracy, losing 12 seconds in one day and then six in another. It is always kept face-down (except when being timed), as I have read that this produces the best accuracy in this model. Early indications suggest that this watch may perform best when it is fully wound, as its day-to-day timings could be as good as -4 SPD, but if left to unwind over the weekend it could drop to -10 SPD.


I have tested this watch over a number of days with the 'Watch Check' app. on my Nexus. Dial down, the results so far have been as follows:

Day 1 +7.9 SPD

Day 2 +7.8 SPD

Day 3 +8.4 SPD (the watch had been allowed to wind down longer between Day 2 and Day 3, than it had been between Day 1 and Day 2)

Day 4 (no winding, no timing)

Day 5 +9.6 SPD

Day 6 +16.7 SPD - This was really surprising

I performed these timings at the same time as the timings of my other Sistem51, and that watch did not show such a big change