Audemars Piguet Royal Oak Double Balance Wheel Openworked 41mm

Audemars Piguet powerfully demonstrates the theory that “two is better than one” in the Royal Oak Double Balance Wheel Openworked, a coveted collector’s model with two balance wheels for increased chronometric precision and viewing pleasure. Following the recently released 37mm tone-on-tone gold version, AP proposes a trilogy of 41mm models in steel, black ceramic and 18k yellow gold cases paired with contrasting tones for the openworked architecture of calibre 3132.

Introduced in 2016, the Royal Oak Double Balance Wheel Openworked ref. 15407 (explained by former AP CEO F.H. Bennahmias) was an updated version of the already very admired and sought-after calibre 3120, revealed in all its splendour inside the skeletonised Openworked Selfwinding ref. 15305. Still skeletonised, the 2016 model was given a dynamic boost with its double balance wheel escapement. Providing twice the viewing pleasure front and back, the double balance calibre 3120 was essentially developed to increase the chronometric performance and stability.

AP is not the first brand to explore the double balance setup but took a different route and positioned the two balance wheels and two hairsprings on the same axis, connected via a central balance staff. Not only is the weight distributed evenly to reduce friction, and there is more mass, but AP’s patented mechanism is also easier to access. Since each balance is fitted with eight inertia blocks (a total of 16), the watch can be precision-tuned.

The 41mm case with a lean height of 9.9mm exhibits the Royal Oak’s iconic traits with the signature octagonal bezel with eight screws and the integrated bracelet. Decorated with vertical satin-brushed finishings and brightly polished bevels, the geometry of the Royal Oak is unmistakable. However, when it comes to the ceramic model, the finishings take five times longer to execute than its metal counterparts.

While black ceramic, gold and steel are not novel case materials for the 41mm RO Double Balance Wheel Openworked, the contrast between the case and the movement is striking. The steel and black ceramic versions, with their pink gold-toned openworked displays, are particularly captivating. Heightening the contrast further, the black ceramic and steel models feature rose gold screws to match the colour of the movement. The yellow gold model emphasises the multiple components of calibre 3120 with an anthracite movement.

The art of openworking has been an AP speciality since the 1930s. By removing as much material as possible from the mainplate and bridges, light floods the movement from the front and back. Using CNC machining, the elaborately shaped bridges are cut and then decorated with traditional finishings, including polished bevels, straight-grained surfaces and V-angles that can only be executed by hand.

In addition to the balance wheels visible on the dial and caseback, the gear train and mainspring are easy to spot. To assist legibility, which is always an issue with skeletonised watches, the hour and minute hands have a thin luminescent insert, as do the applied hour indices on the flange. Although the 3Hz frequency of the balance wheels consumes a lot of power, the calibre 3132 still delivers a respectable autonomy of 45 hours.