Audemars Piguet: Royal Oak Selfwinding Perpetual Calendar Openworked

A perfectly readable perpetual calendar, despite the skeleton format.

In early February, Audemars Piguet introduced a series of new products, including 3 perpetual calendars. The brand’s attention to “evenings” is understandable: Audemars Piguet has been producing models with the perpetual calendar option since 1984. In this review, we will tell you about the Royal Oak Selfwinding Perpetual Calendar Openworked Ref. 26685XT.OO.1320XT.01. The watch runs on a new caliber 7139, which is actually not entirely new, and uses the best practices of Audemars Piguet in creating models with a perpetual calendar.

The body of the novelty is surprisingly balanced. At 41 x 9.5 mm, the watch appears thinner than the earlier Royal Oak watches with an open dial. The case design combines titanium and Bulk Metallic Glass (BMG). The latter (metal glass) is used for the bezel, back cover and rivets of the bracelet. If titanium has a satin finish, then the metal glass parts have been mirror polished, which creates the effect of a “liquid” glow.

Due to the reduced thickness of the integrated bracelet, the watch sits steadily on the wrist. The base of the bracelet is titanium, and the finish alternates between matte and polished surfaces. The water resistance here has been improved to 50 meters, meaning that the watch can actually be worn, rather than stored in a safe, occasionally put on and protected from the slightest speck of dust.

Despite the skeleton format, which often creates visual confusion, the developers managed to achieve both a balanced image and a good readability of the dial. The dial is made of sapphire, which exposes the design of the mechanism, but … the counters of the calendar have darkened edges and seem to “hover” over the mechanism, without interfering with the bridges and gears in the overall picture.

The counters on the dial are positioned so that it is as convenient as possible to read the date. At the “9 o’clock” mark, there is an indicator of the days of the week with an integrated 24-hour indicator. You can see the date indicator at 12 o’clock. There is a leap year cycle indicator at the 3 o’clock mark. The lunar phase indicator is traditionally located at 6 o’clock.

The index of the ordinal number of the week in the year is printed on the inner bezel. The information is displayed using an additional central arrow and is easy to read due to the classic white-on-black contrast. The hour and minute hands are made of rose gold and filled with luminescent material. The hands on the counters are also made of rose gold.

The calibre 7139 installed in the watch is nothing more than a skeletonized version of the calibre 7138. Based on the ultra-thin calibre 7121, which is used in classic Royal Oak Jumbo models, this mechanism combines all the functions of the perpetual calendar into a single-layer design with a thickness of only 4.1 mm. The frequency of balance fluctuations in the mechanism is 28,800 pcs/hour, and the power reserve is 55 hours.

The most interesting option of this calendar is to control all the functions of the watch using the crown. The crown has four positions. In its standard form, it is used to wind up the mechanism. The middle position is used to adjust the calendar: a clockwise rotation adjusts the date, and a counterclockwise rotation adjusts the month and leap year.

The full extension of the crown is used to set the time, and the adjustment of the day of the week and the number of the week clockwise and the phases of the moon counterclockwise is made from a special adjustment position, which is achieved by pulling the crown one step back from full extension. The time zone in which calendar readings cannot be adjusted is marked in red on the 24-hour indicator.

This model is available exclusively in Audemars Piguet boutiques. The estimated cost of the watch (the issue is stated as limited) is CHF 180,200 excluding taxes.