Audemars Piguet celebrates its 150th year with a chronograph that abandons conventions the brand followed for decades. The Royal Oak Jumbo Chronograph RD#5, issued in 150 examples at CHF 260,000, squeezes a flying tourbillon and flyback chronograph into the familiar Jumbo shell—39mm across and 8.1mm thick—while re-engineering how fingers meet the pushers.
The advance sits in the feel of the buttons. Normal chronographs rely on heart-shaped cams demanding strong thumb pressure to drag hands back to zero. The pushers feel stiff because cam geometry and spring tension fight the finger. AP swaps the hearts for a rack-and-pinion train that stores energy while the stopwatch runs, then dumps it the instant the wearer presses reset. The new pushers need only one-tenth to one-twenty-fifth the former force and give a clean click like a phone key instead of mushy resistance.
The system also changes how the counters behave. At each minute’s end the pinion teeth disengage, the rack snaps back to zero and the motion flips the minute counter forward one step. The same stored energy nudges the hour counter gradually. One final piece releases every rack at once when the user resets hours, minutes and seconds together.
Calibre 8100 adds a clutch mixing virtues of horizontal and vertical types. Oblique-toothed wheels rise to meet each other vertically, drive engages instantly without sliding friction, yet the whole unit stays flat enough for the 8.1mm case. A peripheral rotor circles the chronograph works, trimming thickness and leaving the entire mechanism in view.
The outer shell pairs grade 5 titanium with bulk metallic glass, an amorphous alloy that is both hard and elastic. AP first used a palladium-rich BMG blend in 2021; it resists scratches and corrosion and shines like platinum while weighing less. The Bleu Nuit dial keeps the petite tapisserie squares of every Royal Oak and the three chronograph subdials sit slightly above center so the face looks balanced.
Five years of work and one patent produced the RD#5. As with earlier RD projects, the mechanisms inside this watch will reappear in later Audemars Piguet production models.
