I flew to Geneva early this month for the exclusive preview of Chopard’s most complex timepiece to date: the L.U.C Grand Strike, unveiled globally on November 19. Introduced in 1997 and named after Chopard founder Louis-Ulysse Chopard, the L.U.C collection epitomises the highest standard of Swiss watchmaking. Each L.U.C timepiece is crafted at Chopard's Geneva and Fleurier manufactures. Marking the 30th anniversary of Chopard Manufacture, the unique chiming timepiece is a milestone of both technical and acoustic innovation. Developed entirely in-house over more than 11,000 hours of research, the watch unites three of horology’s most prestigious chiming complications: Grande Sonnerie, Petite Sonnerie, and Minute Repeater. The Grande Sonnerie chimes both hours and quarters, while the Petite Sonnerie only chimes the quarters. The minute repeater, on the other hand, chimes the hours, quarters, and minutes on demand. But what makes this watch exceptional is that all its chiming functions are powered by sapphire crystal gongs unique to Chopard.
Chopard Manufacture in Geneva |
A Landmark in Swiss Watchmaking
The L.U.C Grand Strike is powered by the in-house L.U.C 08.03-L calibre, a 686-component manual-winding movement that combines precise timekeeping with a 60-second tourbillon. The watch carries both the Poinçon de Genève (Geneva Seal), an independent institution that certifies the highest level of manufacturing and finishing of components, and the Contrôle Officiel Suisse des Chronomètres (COSC), which certifies the accuracy of movements. The L.U.C Grand Strike is one of the rare Grande Sonnerie watches to meet both chronometric and aesthetic standards of the highest order.
Encased in 18-carat ethical white gold, the 43mm watch remains remarkably wearable at just 14.08mm thick. An open-dial construction reveals the finely finished movement and a pair of polished hammers at 10 o’clock, offering a view into the chiming mechanism. A discreet slider on the case flank allows the wearer to choose between Grande Sonnerie (G), Petite Sonnerie (P), and Silence (S) modes.
A watchmaker works on a Grand Complication at the Chopard manufacture |
Sapphire Gongs and the Quest for Purity
The hallmark of the L.U.C Grand Strike lies in its acoustic system. Unlike traditional chiming watches that use steel gongs, Chopard’s timepiece features gongs machined from a single block of sapphire crystal, fused directly to the dial. This patented “monobloc” structure transmits sound directly through the watch crystal, eliminating energy loss and producing exceptionally clear tone.
The sapphire gongs have a square cross-section, allowing greater surface contact with the hammers and directing sound vibrations more efficiently. The result is a chime that is powerful, refined, and pure in pitch.
Working in collaboration with Geneva’s Haute École du Paysage, d’Ingénierie et d’Architecture (HEPIA), Chopard measured significant gains in clarity and amplitude compared with traditional metal gongs. Sapphire’s hardness—second only to diamond—ensures the gongs remain perfectly rigid and unaltered over time. Chopard fittingly refers to this acoustic signature as “The Sound of Eternity.”
Gemsetters tools at the Chopard manufacture |
Inside the Mechanical Symphony
34 components work in harmony to perform each chiming sequence, coordinated by 22 finely adjusted blade springs. In sonnerie mode, the watch chimes automatically; in minute repeater mode, the wearer activates the pusher to sound the hours, quarters, and minutes. In Grande Sonnerie mode, the watch strikes both hours and quarters as they pass; in Petite Sonnerie, it sounds the hours at the top of the hour and quarters every 15 minutes thereafter.
Two independent mainspring barrels drive the movement: one for timekeeping, another for the sonnerie. The chiming barrel provides 12 hours of power in Grande Sonnerie mode, while the main barrel offers a 70-hour power reserve. Remarkably, the watch’s escapement runs at 4 Hz (28,800 vibrations per hour), an unusually high frequency for such a complex timepiece, ensuring superior accuracy and stability.
The L.U.C Caliber 08.03-L powers the timepiece |
Innovation and Protection
To ensure reliability and ease of use, Chopard has incorporated 10 proprietary patents, 5 of which were developed specifically for this model. These include new safety systems that prevent the chime from activating with insufficient power and allow secure switching between modes. Performance-enhancing patents cover an energy-efficient clutch, a hammer design that reduces impact stress on the gongs, and a mechanism that guarantees full, uninterrupted chimes.
Every L.U.C Grand Strike undergoes a series of endurance tests at the Fleurier workshops. Over three months, each watch performs 62,400 sonnerie activations, during which the gongs are struck more than 500,000 times. The process ensures the watch’s precision and durability under real-life conditions.
Chopard L.U.C Grand Strike |
Two Decades of Chiming Expertise
The Grand Strike builds on nearly two decades of research into acoustic complications at Chopard. The brand’s first chiming watch, the L.U.C Strike One, debuted in 2006, followed by the L.U.C Full Strike in 2016—also the first minute repeater to employ sapphire crystal gongs. The Full Strike earned the industry’s highest accolade, the Aiguille d’Or at the 2017 Grand Prix d’Horlogerie de Genève (GPHG). The new Grande Sonnerie takes that technology further, combining automatic chiming capability with a tourbillon-regulated, COSC-certified movement.
Design, Craft, and Materials
Despite its mechanical complexity, the L.U.C Grand Strike maintains a balanced aesthetic. The open-dial design reveals the heart of the mechanism, with its bridges and plates crafted from German silver, an alloy known for its warm patina and the high level of finishing it demands. Its gold hands and hour markers complete the composition, while interchangeable straps allow for versatility.
An Intersection of Sound and Time
In Chopard’s universe, music and watchmaking are twin disciplines—both governed by precision, proportion, and emotional resonance. For collectors and connoisseurs, the L.U.C Grand Strike is not only a technical triumph, but also a poetic statement: that time, when it sings, can be beautiful beyond measure.
