The New AP Royal Oak Selfwinding Perpetual Calendar Openworked

Perpetual calendars are, without a doubt, an integral part of Audemars Piguet’s history, and the Royal Oak has carried its strand very convincingly since 1984. With the introduction of the Royal Oak Selfwinding Perpetual Calendar Openworked powered by the new Calibre 7139, AP signals a clear generational shift. Released alongside a Code 11.59 counterpart, which is an exquisite, beautiful watch, this Royal Oak version is the one that feels most resolutely AP… Let’s be honest, given the choice, most of us would quite naturally go for a Royal Oak.

The Case and the Bracelet

At 41mm in diameter and just 9.5mm thick, the case impresses with its balance. This is a perpetual calendar that feels slimmer and somehow more wearable than earlier openworked Royal Oak QPs ref. 26585. The construction combines lightweight titanium with AP’s proprietary Bulk Metallic Glass (BMG), used for the bezel, caseback frame and bracelet studs, already seen in the 150^th Anniversary QP ref. 26585XT. The satin-brushed titanium contrasts with the mirror-polished BMG flashes of a liquid-like glow; the combination feels both precious and technical.

On the wrist, the watch wears flatter and more planted than expected, thanks to the integrated bracelet and its reduced thickness. The titanium bracelet with the BMG studs is light, fluid and exceptionally well finished, with alternating brushed and polished surfaces that echo the case. When worn, the watch feels substantial without being heavy, a “technical” piece, not a precious burden. The improved 50m water resistance strengthens the sense that this is a perpetual calendar designed to be worn, not handled with caution.

The openworked Dial

In theatre, experimental shows often walk a fine line between spectacle and confusion; the same happens with openworked/skeletonised perpetual calendars. Here, AP gets the balance essentially right. The sapphire dial exposes Calibre 7139 while retaining a surprisingly good level of legibility. There´s visually pleasant depth; the smoked-on-the-edge subdials for the calendar indications float above the movement without dissolving into it.

The layout follows a logical European order: day at 9 o’clock with an integrated 24-hour indicator, date at 12, month and leap year at 3, and the moon phase at 6. The week numbers are printed on the inclined inner flange, which is a clever use of space. In practice, apart from the hour and minutes, indicated by the pink gold Royal Oak hands filled with luminous material, the current week number is easiest to pick as it is white on a black flange and indicated by the centrally mounted hand. For the rest of the QP indications, the small pink gold hands do seem a bit mixed in, but a slight twist of the wrist makes the light hit their surfaces at the right angle, and there you have it: all are readable at a glance. This said, overall, the dial feels calmer, still complex, but not visually anxious.

The Calibre 7139

The new Audemars Piguet Royal Oak Selfwinding Perpetual Calendar Openworked is powered by Calibre 7139, the openworked evolution of last year’s Calibre 7138. Based on the ultra-thin automatic Calibre 7121 found in the classic Royal Oak Jumbo, it integrates all perpetual calendar functions into a single layer, drawing on AP’s RD#2 research and the RO Perpetual Calendar Ultra-Thin. The movement measures 4.1mm thick, beats at 28,800 vibrations/hour and offers a 55-hour power reserve.

From the user’s perspective, the coolest feature is the all-in-one crown system for all the functions. No recessed correctors, no tools, no anxiety, but studying instructions is highly advisable. There are four crown positions: to allow winding (normal), the middle position is for calendar adjustment, turning clockwise adjusts the date, while turning counter-clockwise adjusts the month and leap year. Full pull is for time setting, and correction of the day of the week and week number clockwise, and the moon phase counter-clockwise are made from the special correction position, reached by pushing the crown back one step from the full pull. 

Sounds complicated, but the reality is no stress. Also, the safeties are in place, and the no-correction zone is marked in red on the 24-hour indicator within the 9 o´clock subdial. This ease of setting fundamentally changes the experience, turning what is often a fragile ritual into something reassuringly simple, in the best possible way. Finishing is classic Audemars Piguet: hand-chamfered bridges with sharp internal angles, satin brushing, circular graining and polished accents. The openworked rotor, barrel bridge and balance bridge take on a pink gold tone, adding warm colour to the otherwise monochrome movement.

Availability and price

The Audemars Piguet Royal Oak Selfwinding Perpetual Calendar Openworked 26685XT is available exclusively through Audemars Piguet boutiques. The price is CHF 180,200 excluding taxes, and production will be highly limited. For more information, please visit AudemarsPiguet.com.