Unfortunately, the quality control test demonstrated that a day of standard motion is not enough to fully wind the watch. This is important because it means that any issues with power reserve are a result of insufficient winding. In fact, I fully wound the stand-alone movement and observed that it ran for 125 hours before coming to a stop so we know that the watch is capable of storing enough energy and operates with sufficient efficiency to deliver the full 5-day power reserve with a little left in the tank. When manually winding this watch it takes more than 100 turns of the crown to fully wind it up, where most watches would be fully wound with about 40 turns of the crown.

Before addressing this I think it is important to note that it takes a lot to fully wind a double barrel (5-day power reserve) watch. This 7-day test brought to light one of the first complaints I have heard from individuals who have purchased this watch and that is that they don’t seem to get the full 5-day power reserve as advertised by Oris. Fig 4 – Arrow indicating how to let down the power Servicing these watches should be straight forward for any watchmaker. This watch requires both and is marked with an arrow indicating you must loosen the screw and another pointing to the button to release the spring tension. Most watches require you to either turn a screw or depress a button. Also, the double release for the winding stem (a feature exceedingly rare in watchmaking) is also well marked. The click is clearly labeled with an arrow.

For example, with two barrels it can be more difficult than normal to figure out how to release the power stored by the mainsprings before servicing the watch. Anything that is out of the ordinary is clearly marked to aid the watchmaker in his service. The watch comes apart and goes together easily.

Often brands don’t think about what will happen when the watch needs to be serviced, but in this case, it is apparent that the needs of the watchmaker were considered. From the watchmaker’s perspective, it even looks like they designed the caliber 400 with after-sales service in mind.

Oris aquis date calibre 400 39mm