Audemars Piguet (AP) first unveiled the Royal Oak Double Balance Wheel Openworked in 2016, in full-sized 41 mm format. It’s a technically interesting take on the brand’s signature luxury-sports watch. While it is a time-only watch, the skeletonised movement sports a pair of mirrored, superimposed balance wheels and hairsprings.

Though already available in 37 mm with a sparkly “frosted” case or entirely gem-set, the 37 mm model wasn’t offered in the classic Royal Oak finish. Now the movement makes its debut in a compact 37 mm case in the traditional brushed-and-polished finish. It’s available in either pink or white gold with the open-worked movement colour-matched to the case metal.

Initial thoughts 

The Double Balance Wheel model is something of a halo model for the Royal Oak range. Though it is not complicated in the functional sense, it is equipped with an interesting feature that theoretically contributes to chronometry. Add to that the distinctive aesthetics of the skeletonised movement, and the result is a watch that is classical Royal Oak in design yet more sophisticated in technical terms.

The original 41 mm model, however, was fairly large, and the angular form of the Royal Oak accentuated the size. The original 37 mm models were extravagant and perhaps too over-the-top for everyday wear. The new pair is easily more wearable and should appeal to a wider audience.

The new models are each priced at US$98,100, which is comparable to the earlier versions with a frosted finish. Though it seems like a big number for a time-only watch, the price is relatively reasonable considering the skeleton movement, double balances, and the all-gold bracelet.

Classic Royal Oak

The new models are essentially more traditional takes on the Royal Oak Double Balance Wheel Openworked 37 mm. Replacing the frosted finish on earlier versions is the old-school matte brushed accented by polished bevels.

Both versions are identical in size at 37 mm in diameter and 10 mm thick. That’s 4 mm smaller than the full-sized model, and 0.1 mm thicker. The result is a watch that is proportionately thicker, giving it a slightly chunkier look.

The model is available in two guises: white gold with a rhodium-finish movement, or pink gold with a matching movement. Each has colour accents on the dial: the white gold model has a pale blue flange along with hour markers and hands in pink gold, while the pink gold model has a purple flange along with white gold hands and indices.

Cosmetic tweaks aside, the key feature of the watch is the cal. 3132 with double balance wheels. Secured by a full bridge visible between seven and nine o’clock, the twin balances boasts cumulatively greater inertia than a single balance, resulting in better stability over time. Moreover, each hairspring is superimposed but offset by 180 degrees, so the hairsprings “breathe” in opposite directions, which theoretically means they each cancel out the other’s positional errors.

The twin free-sprung balance wheels oscillate at 3 Hz, while the skeletonised rotor winds a single barrel that delivers a 45-hour power reserve. This is substantially than the 60 hours of the equivalent cal. 3120/3129 with only a single balance. That’s because the additional balance requires additional energy to oscillate, essentially twice the energy of a single balance, which trims the power reserve.

The skeletonisation is all about a monochromatic finish, clean lines, and geometric shapes

Key facts and price

Audemars Piguet Double Balance Wheel Openworked 37 mm
Ref. 15467BC.OO.1256BC.01 (white gold)
Ref. 15467OR.OO.1256OR.02 (pink gold)

Diameter: 37 mm
Height: 10 mm
Material: 18k white gold or pink gold
Crystal: Sapphire
Water-resistance: 50 m

Movement: Cal. 3132
Functions: Hours, minutes and centre seconds
Winding: Automatic
Frequency: 21,600 beats per hour (3 Hz)
Power reserve: 45 hours

Strap: Matching bracelet with folding clasp

Limited edition: No
Availability: At AP Houses and boutiques
Price: US$98,100

For more, visit Audemarspiguet.com.