Audemars Piguet has spent this year celebrating the 150th anniversary of the brand with some pretty special timepieces honoring the past, while previewing an exciting vision of the future. Nowhere is this more apparent that in the highly anticipated RD#5 revealed this morning, a watch that celebrates the origins of the Royal Oak, while showcasing a new approach to the automatic chronograph in rather dramatic fashion. This is the final installment of the “RD” series, and it is officially called the Royal Oak “Jumbo” Extra-Thin Selfwinding Flying Tourbillon Chronograph featuring the caliber 8100, and while all those complications in the name may sound relatively straightforward, there’s a lot going under the surface courtesy of Renaud & Papi (APRP) that’s worth nerding out over.
Audemars Piguet launched their Research and Development (RD) series in 2015 with the Royal Oak Concept Supersonnerie prototype that took aim at creating a new chiming technology set within a 44mm titanium case. In the years since, we’ve seen all manner of technical innovation come from the project, as you might expect, and 10 years later, the final iteration is returning to the RD#3 in a sense, which was the first “Jumbo” Royal Oak to receive a self-winding flying tourbillon. With the RD#5, that concept is dialed up to 11 with the addition of a truly groundbreaking chronograph. Oh, and the original Jumbo dimensions of 39mm by 8.1mm in thickness remain unchanged, even if rendered in titanium and precious bulk metallic glass (BMG).
When the original Royal Oak ref 5402 was released in 1972, its 39mm diameter was seen as quite large for the era, and quickly earned the “Jumbo” nickname. Over 50 years later and the term has stuck, now signifying reference of the same lineage so to speak. In the current Royal Oak collection, that distinction falls to the ref. 16202, which gets the same 39mm frame, though at 8.1mm in thickness it’s ever so slightly thicker than the original, though still quite slim, all things considered. This watch is also differentiated by the “AP” placement at the bottom of the dial, and the tighter Petite Tapisserie dial pattern. Both details serve as a nod to the original.
This particular strain of Royal Oak is prized for its world class ergonomics thanks to the svelte dimensions and tapering integrated bracelet designed by Gerald Genta, and executed with the help of Gay Frères. It is truly a watch that needs to be worn to be fully appreciated. With this RD#5, it was important that this ergonomic quality of the watch remain uncompromised. To achieve this, Audemars Piguet were forced to re-think their structural approach to the chronograph, much in the same way they did with the perpetual calendar built for the ultra-thin, 6.3mm thick RD#2. The result is the caliber 8100.
In a standard mechanical chronograph, the reset mechanism uses a hammer and heart shaped cam to move the timing seconds hand back into position when timing is stopped. When flyback functionality is added, a clutch is disengaged while another lever simultaneously resets the timing hand. These levers and cams take up quite a bit of space, and this is why, on average, watches equipped with a mechanical chronograph are quite thick, much to the chagrin of the enthusiast community. With the caliber 8100, Audemars Piguet did away with this system entirely, instead relying on a rack system that has been flattened to a single layer.
This rack system brings a few benefits to the table. First, it can operate in a very low profile, allowing for a more compressed movement overall. Second, the manner in which they’ve been designed is optimized for efficiency. When the chronograph is actuated, a column wheel engages a vertical clutch which links the timing mechanism with the going train, and the timing hand jumps to life along with the rack system attached to it. The racks gather energy from the rotation of the chronograph timing hand, and use it to instantaneously jump the minute counter, and in turn, the hour counter. Three racks operate on the pivot of each timing wheel, connected via levers though each on their own pivot point. A special bridge containing the jewels for these pivots also holds the system in place on its own plane. The racks resemble a string marionette in action.
There’s something of a hub and spoke design connecting each of the timing elements, and this hub helps to manage the stop and reset mechanism when the stop/reset button is pressed. This disengaged the clutch from the chronograph wheel, and shifts brakes in place on each of the pawls set against the seconds, minutes, and hour wheels. With these lifted, the hands of each can return to their starting positions, and if this is done while the chronograph is running, the whole thing immediately restarts.
One of the talking points from Audemars Piguet when designing this system was the tactility of the actuation. The buttons themselves sit nearly flush against the case, almost like a button you’d find on the side of the phone in your pocket, and that’s no coincidence. The inspiration for the tactile feel of the press of these buttons is taken from exactly these types of buttons on the side of your phone. When considering typical chronograph buttons: “Their travel – that is the distance they must be pressed – is often 1 mm or more and requires a force of around 1.5 kilograms,” explains Giulio Papi, Director of Watchmaking Design. “Our aim was to reduce these values to enhance the client experience, drawing inspiration from smartphone buttons which typically have a travel of 0.3 mm and require 300 grams of force.”
The whole chronograph system that’s been devised for the caliber 8100 here is nothing short of remarkable, and it’s one of those things that almost makes too much sense in hindsight, that you wonder how it hasn’t been done like this before. I’d love to see a similar system put in place in more regular production chronograph references from the brand, because there’s more to this RD#5 than just the trick chronograph works.
You may not have noticed at a glance, but this is an automatic movement, with a peripherally mounted oscillating weight framing the drama taking place at the center. With a movement this thin, automatic winding feels like a necessity, however it does boast an impressive 72 hour reserve beating at 3Hz. But that’s not all. As stated, this watch picks up where the RD#3 left off, and that means it also includes a flying tourbillon, which is visible through a large aperture at six o’clock on the dial side.
If I’m being completely honest, I don’t think that the RD#5 needed the flying tourbillon, as it kind of steals some of the thunder from the chronograph system on display. But that doesn’t make it any less impressive. This is a showpiece at the end of the day that serves as a technological tour de force, and in that regard, it doesn’t hold back. That’s not even the final trick up this watch’s sleeve.
Winding and setting of the watch happens through the crown at three o’clock, as you’d expect, but this one isn’t the pull out variety. Instead, there is a button nested within the crown that can be pressed to change the crown’s function. When left alone, the crown winds the mainspring, and when pressed, the crown shifts to setting the time. This isn’t the first time we’ve seen this feature, but it never really gets old.
Stepping back, the RD#5 Royal Oak “Jumbo” Extra-Thin Selfwinding Flying Tourbillon Chronograph is a fitting endcap to the RD series of watches. It combines many of the details we’ve seen separately throughout the project, and serves as a final testament to the brand’s technical knowhow and ambitions. It also recognizes what makes the “Jumbo” Royal Oak so special in the first place, and goes to great lengths to preserve those features. The scripted Audemars Piguet signature at the top of the dial brings both of these worlds together, while capping off an eventful 150 years of operation.
The RD#5 is limited to 150 pieces planned for production, each with a retail price of CHF 260,000. Audemars Piguet