The Audemars Piguet Royal Oak Jumbo Extra-Thin Openworked 16204ST (Live Pics & Price)

1972-2022. Yes, Audemars Piguet‘s most emblematic watch, and one of the most iconic watches of the entire industry, the Royal Oak, is celebrating its 50th anniversary – even though, looking at the watch, it doesn’t reveal its age. As you’ve come to expect, the brand will be using this jubilee as the occasion to revamp some of the models, introduce new in-house movements, launch special editions, etc. Well, we’re talking about an entire 50-year collection. Following the replacement of the Royal Oak Jumbo Extra-Thin, with the new 16202ST we presented here, the brand has also announced a new Extra-Thin Openworked. Following the tradition established for the 40th anniversary of this watch, it’s time to discover the new steel Audemars Piguet Royal Oak Jumbo Extra-Thin Openworked, a.k.a the 16204ST. 

Openworked & Royal Oak

The whole idea of an openworked movement on the Royal Oak is far from new. In fact, the Royal Oak collection has included more than 50 openworked models to this day, of course with various movements, styles, sizes, and materials. But we’re here to talk about the Jumbo Extra-Thin Openworked, a much rarer breed in the brand’s collection.

The whole concept of openworking or skeletonisation, the task of painstakingly and manually removing material from the movement’s plate and bridges to reveal some of the inner mechanics, is not new at AP. It used to be one of its areas of expertise between the 1930-1950s. This artistic craft resurfaced in the 1970s, specifically on the Calibre 2120 – that same movement that has equipped the Royal Oak Extra-Thin since its creation. Openworking only appeared in the Royal Oak collection in 1981 with a pendant version – ref. 5710BA – followed in 1986 with ref. 25636 equipped with the ultra-thin self-winding perpetual calendar Calibre 2120/2800.

The first Royal Oak Jumbo Extra-Thin Openworked was launched in 1992, within the 30th anniversary “Jubilee” collection. This reference 14811 was, however, a one-of-a-kind model auctioned for a foundation. Several Jumbo models equipped with extra-thin Calibre 2120 were introduced in very small series until the year 2000. In 2012, the brand returned to openworking the Royal Oak Jumbo Extra-Thin with the reference 15203PT, a 40-piece limited edition released in the frame of the 40th-anniversary celebrations. This model features a 39mm platinum case and is powered with calibre 5122. In 2014, a pink gold version (ref. 15204OR) was released. And just like the brand did for the 40-year collection, there’s a new RO Jumbo Openworked coming for the 50Y collection.

The Basics of the 16204

So, here it is, a new Royal Oak Jumbo Extra-Thin Openworked. But as we’re talking about the 50-year collection, you can easily imagine that Audemars Piguet hasn’t just re-issued the previous model with only a few minor updates. Indeed, the 16204ST is still firmly a Royal Oak Jumbo and, in this instance, it shares its case, dimensions and proportions with the classic closed-dial Jumbo 16202. But mechanically, that’s another story here too.

So let’s summarise all you need to know about this Royal Oak Jumbo Extra-Thin Openworked 16204ST before going into the details:

• Classic Jumbo case, 39mm x 8.1mm, just like the closed-dial 16202
• Same bracelet, same clasp, same bezel, same overall style
• It’s made of STEEL. Yes, contrary to the 40th-anniversary model, Audemars Piguet has decided to stay true to the original material and offers the Jumbo Extra-Thin Openworked in the most expected material. Note that there’s an 18k rose gold version too, under the reference 16204OR
• It’s not limited, even though it won’t be produced in high numbers
• It has a brand new self-winding, extra-thin movement, the Calibre 7124, which is based on the new-generation, in-house produced Calibre 7121 introduced in the closed-dial Jumbo 16202
• It is a no-date watch, and its movement is finished with extreme attention to detail

Let’s now look at the 16204 more closely.

The Royal Oak Jumbo Extra-Thin Openworked 16204ST

As you’ve seen with the basics above, the Royal Oak Jumbo Extra-Thin Openworked 16204ST we’re presenting to you here is basically an openworked, no-date version of the Royal Oak Jumbo Extra-Thin 16202. As such, there’s not a single difference regarding the habillage. The case, bezel, crown, caseback, bracelet and clasp are all identical. What changes has to do with the movement and, you’ve guessed it, the absence of a dial.

The case of the Audemars Piguet Royal Oak 16204 is thus the same as what’s used in the closed-dial 16202 introduced at the same time. And that means the same case as the previous generation Jumbo, the 15202. At 39mm in diameter, it stays true to the proportions used on the original 1972 Royal Oak reference 5402. The height of the case, being an extra-thin watch, is measured at 8.1mm, the same thickness as the previous generation Jumbo, and just a bit thicker than the original 1972 model – mostly explained by the use of a sapphire caseback. Water-resistance in this Openworked 16204ST is still rated at 50 metres.

The emblematic octagonal bezel, with its eight white gold screws, is intact and still relies on a large polished bevel on its periphery. The stainless steel case creates no surprises, with the classic design and combination of vertically-brushed surfaces and polished accents on the edges we’ve come to expect from a Royal Oak. Let’s be honest, regarding the habillage; we’re in familiar territories. It’s a deliberate choice from Audemars Piguet, which wanted to keep the spirit of the original Jumbo alive. Maybe there will be more daring versions in other ranges – automatic, chronographs, complications – but the Jumbo is a 50 years old icon that deserves some respect, and AP wanted to maintain the legacy. Like it or not…

While on a classic Royal Oak Jumbo Extra-Thin I would have now talked about the dial and described its petite tapisserie pattern, there’s no such thing here. The central part of the watch is entirely devoted to showcasing the movement. A few interesting points nevertheless. The movement is framed by a tone-on-tone rhodium-plated inner bezel, on which is printed a black minute track and applied facetted, short yet luminous hour markers. The hands are executed in the same vein and are actually bolder and more angular than the classic RO hands found on the closed-dial Jumbo. Most probably to accentuate the contrast with the movement. The same can be said about the choice to have the hands and markers done in 18k pink gold, even though, like for many fully openworked watches, legibility isn’t the main quality of the Jumbo Extra-Thin Openworked 16204ST.

Let’s now talk about the movement, the Calibre 7124. As Frank explained in his in-depth article on the new Jumbo 16202, the main evolution of the 50th-anniversary collection, at least for the Jumbo models, is to be seen inside the cases. After 50 years of using the JLC-based movement, known internally under the reference 2121, the Royal Oak Jumbo models finally get modern mechanics developed and produced in-house. And while the 16202 gets the self-winding Calibre 7121, the Openworked 16204 receives its skeletonised brother, the Calibre 7124.

Calibre 7121 and 7124 were developed in parallel, which means that the position and geometries of the different components equipping both movements result from the wish to make a harmonious and well-balanced openworked version. Both share the same mechanical architecture, with extra-thinness in mind, but also more reliability and comfort than the previous Calibre 2121. The 2.7mm Calibre 7124 – thinner than the one used in the closed-dial model, due to the removal of the date mechanism – thus boasts 57 hours of power reserve despite a higher frequency of 4Hz. It is equipped with a contemporary slim oscillating weight mounted on ball bearings, offering bidirectional winding. The balance wheel is fitted with inertia blocks.

What sets the Calibre 7124 apart from the 7121 is first the absence of a date, second – obviously – the openworking applied by AP’s watchmakers. The process is combining modern techniques, as the preliminary geometries of the mainplate and bridges are cut through CNC machining and electric discharge machining (EDM), with traditional decoration techniques. The parts are then entirely finished by watchmakers, revealing no fewer than 324 polished V angles – which, as you might know, can only be done by hand. The result is a technical and geometric movement with an almost spider-web effect that frames the main components, meaning the barrel and the balance wheel. The back reveals the same overall design intention and uses the mirror transversal bridges for the balance and the barrel. It features the “50 Years” oscillating weight that is reserved for the 2022 production only.

In addition to the stainless steel 16204ST version presented here, the Audemars Piguet Royal Oak Jumbo Extra-Thin Openworked will also be available in 18k pink gold, with a movement that is executed in slate grey for more contrast.

Availability & price

The Audemars Piguet Royal Oak Jumbo Extra-Thin Openworked in stainless steel (reference 16204ST.OO.1240ST.01) is presented as part of the permanent collection and isn’t limited. The price is EUR 86,800 for the steel version and the gold model will retail for EUR 113,300. For more details, please visit www.audemarspiguet.com.