Calibre 2121
Circa 1985. Technical guide for watchmaker repairers. Audemars Piguet Archives.
1970. Audemars Piguet Showcase at the Basel Fair Since the 1950s, Audemars Piguet has been recognised as one of the main experts in ultra-thin watches. In 1970, this status was confirmed by the launch of Calibre 2121, the thinnest in its category, which came to equip the Royal Oak two years later. Audemars Piguet Archives.
1970. Decoration table for Calibres 2120 and 2121 (VC 1120/1121). Copy of the LeCoultre Cie Plan 24131a for Audemars Piguet. Audemars Piguet Archives.
1967–2011. Calibres 2120 and 2121, caseback side. Extra-thin selfwinding calibres. Diameter of 28 mm (12½ lignes). The aesthetic on the caseback side is similar for Calibre 2120 (between 1967 and 2006) and Calibre 2121 (between 1970 and circa 2011). Movement 127053 produced in 1970. Audemars Piguet Heritage, inv. 365.
1971. Calibre 2121, dial side. Thinnest selfwinding calibre with central rotor and date indication of its time (3.05 mm). Rotor supported by ruby rollers oscillating on a circular rail. Diameter of 28 mm (12½ lignes). 247 parts, 19,800 vph. Derived from Calibre 2120 (1967). Movement 127053. Audemars Piguet Heritage.
1967–2021. Regulating organs that equipped Calibres 2120 and 2121. Main balance-wheel and balance-coq aesthetic and technical evolutions. Top: since 1967; Middle: since circa 1980; Bottom: since circa 1991.
2011. Detailed description of Calibre 2121. Audemars Piguet 2011 General Catalogue. Audemars Piguet Archives.
2007–2019. Calibres 2120 and 2121, caseback side. This openworked oscillating weight is documented in the Audemars Piguet catalogues between 2007 and 2012 for Calibre 2121 and between 2011 and 2019 for Calibre 2120. It was also probably used before and after these dates.
2012–2021. Calibre 2121, caseback side. Crafted for Model 15202 for the Royal Oak's 40th anniversary, this oscillating weight is documented in the Audemars Piguet catalogues until 2021. Retired at the end of 2021, Calibre 2121 has been replaced by Calibre 7121.
Mechanism
Selfwinding
Functions
Hours, minutes, date
Diameter
28 mm (12½ lignes)
Thickness
3.05 mm
Frequency
19,800 vph (2.8 Hz)
Power Reserve
40 hours
Jewels
36
Dates
1970 – 2021
Components
247
Movement Blank
LeCoultre & Cie, then Audemars Piguet (as of circa. 2002)
Created in 1970, Calibre 2121 is a derivative of Calibre 2120 (1967), also powering an aperture-type date display. This additional function raised its thickness to 3.05 mm, making it the world's thinnest mechanical selfwinding movement with a central rotor and date.
The history of Calibres 2120 and 2121 is available here.
Calibre 2121 was introduced in October 1970 in Model 5381. It was fitted in numerous ultra-thin selfwinding watches before being chosen in 1972 for the first Royal Oak, Model 5402. From that date onwards and until its replacement in 2022 by the 7121 (Model 16202), Calibre 2121 was one of the essential attributes of the Royal Oak "Jumbo" watches.
For a long time, Calibre 2121 blanks were produced in Le Sentier by LeCoultre & Cie (renamed Jaeger-LeCoultre in 1979). From the start of the 21st century, it was produced by the Audemars Piguet workshops in Le Brassus.
During its first quarter-century of existence, nearly 20,000 Calibre 2121 watches were produced and used in numerous references across several collections. Since the dawn of the 21st century, with a few exceptions, the calibre has been reserved for the Royal Oak “Jumbo”. Production between 2000 and 2021 exceeded 12,000 units. In 2012, an openworked 2121SQ variation was created for a model celebrating the 40th anniversary of this ultra-thin collection. In 2022, the movement was replaced by Calibre 7121.
Created in 1970, Calibre 2121 is a derivative of Calibre 2120 (1967), also powering an aperture-type date display. This additional function raised its thickness to 3.05 mm, making it the world's thinnest mechanical selfwinding movement with a central rotor and date.
The history of Calibres 2120 and 2121 is available here.
Calibre 2121 was introduced in October 1970 in Model 5381. It was fitted in numerous ultra-thin selfwinding watches before being chosen in 1972 for the first Royal Oak, Model 5402. From that date onwards and until its replacement in 2022 by the 7121 (Model 16202), Calibre 2121 was one of the essential attributes of the Royal Oak "Jumbo" watches.
For a long time, Calibre 2121 blanks were produced in Le Sentier by LeCoultre & Cie (renamed Jaeger-LeCoultre in 1979). From the start of the 21st century, it was produced by the Audemars Piguet workshops in Le Brassus.
During its first quarter-century of existence, nearly 20,000 Calibre 2121 watches were produced and used in numerous references across several collections. Since the dawn of the 21st century, with a few exceptions, the calibre has been reserved for the Royal Oak “Jumbo”. Production between 2000 and 2021 exceeded 12,000 units. In 2012, an openworked 2121SQ variation was created for a model celebrating the 40th anniversary of this ultra-thin collection. In 2022, the movement was replaced by Calibre 7121.
