From Chopard Manufacture’s ateliers emerges the L.U.C Grand Strike, a wholly in‑house creation that crowns the Maison’s long pursuit of chiming watchmaking. This exceptional timepiece combines grande sonnerie, petite sonnerie and a minute repeater fitted with proprietary sapphire crystal gongs, embodying decades of technical refinement initiated by Karl‑Friedrich Scheufele, Co‑President of Chopard.

After more than 11,000 hours of research and development, the L.U.C Grand Strike incorporates ten proprietary patents, five of which were developed specifically for this model, making it the most intricate watch ever produced by Chopard Manufacture. Its reliability and precision have been validated through exhaustive in‑house testing and by independent authorities including the Poinçon de Genève and the Contrôle Officiel Suisse des Chronomètres (COSC), earning it the distinction of being the most comprehensively certified grande sonnerie among contemporary high complications.

The watch marries classical proportions with contemporary restraint, featuring an open dial that showcases the 686‑component calibre L.U.C 08.03‑L. Housed in a compact 43 mm 18‑carat ethical white gold case, the piece directs attention to its movement and to two polished steel hammers at 10 o’clock that signal its chiming function. An ergonomically placed sliding selector beside the crown allows the wearer to choose between Grande Sonnerie, Petite Sonnerie and Silence modes. A 60‑second tourbillon occupies the lower dial, a visual testament to the movement’s COSC‑certified performance. The continuous rotation of the tourbillon together with the chiming mechanism creates a dynamic, immersive mechanical display.

A defining technical innovation is the patented sapphire crystal gong, machined as a single unit with the dial. This unprecedented use of sapphire crystal for the gongs gives the L.U.C Grand Strike its distinctive acoustic signature. Beyond this breakthrough, nine additional patents—covering safety systems, chiming cadence improvements and other functional advances—were applied in the watch’s development. Five of these patents are new and were conceived expressly for this model, underscoring Chopard’s ongoing commitment to inventive watchmaking.

The L.U.C Grand Strike is the culmination of nearly three decades of horological development at Chopard. It builds on almost 20 years of sonnerie know‑how and a decade of sapphire monobloc expertise. The project progressed from exploratory studies to technical plans and a working prototype, with more than 2,500 hours devoted to prototype refinement to achieve micro‑mechanical perfection. Its lineage is visible in earlier high complications from the Manufacture, from the traditional L.U.C All‑In‑One to the experimental multi‑patent L.U.C 8HF, and in milestone pieces such as the L.U.C Full Strike minute repeater, which first introduced sapphire gongs to striking watches.

The resonant qualities of sapphire crystal, scientifically known as monocrystalline aluminium oxide, have long been recognized, yet its fragility led most watchmakers to dismiss the idea of using it for gongs as impractical. Chopard Manufacture challenged that consensus, taking on the technical risks and ultimately succeeding where others had not, transforming a theoretical advantage into a practical, working solution. This breakthrough was first realized in the L.U.C Full Strike, a watch that turned an apparent impossibility into reality and was subsequently honoured with the Aiguille d’Or at the 2017 Grand Prix d’Horlogerie de Genève.

Chopard’s sonnerie story continues with the L.U.C Grand Strike, which elevates chiming complications to their highest expression by incorporating a grande sonnerie that automatically sounds hours and quarters as they pass. The mechanism can be switched to petite sonnerie, which limits hour strikes to the top of the hour and sounds only the quarters every 15 minutes, or set to silence so that chiming occurs only when the minute repeater is manually activated. Each time the chiming system is engaged—whether by the minute repeater or by the automatic grande or petite sonnerie—thirty‑four components spring into coordinated action. Guided by twenty‑two hand‑adjusted blade springs, these parts move from rest to readiness in just 0.03 seconds, a precisely timed sequence of levers, cams and racks that culminates in the hammers striking the gongs to produce a clear, articulate sound.

The movement that orchestrates these functions comprises 686 components and includes a 60‑second tourbillon topped by a small‑seconds display, a constant visual cue to the watch’s chronometric rigor. The L.U.C Grand Strike carries both the Poinçon de Genève and COSC certifications, reflecting its technical refinement and timing accuracy. Managing energy demands was a central engineering challenge. The manual‑winding L.U.C 08.03‑L separates power delivery between two mainspring barrels—one dedicated to timekeeping and the other to the chiming mechanisms—so that the sonnerie can operate reliably even under heavy load. When fully wound, the sonnerie barrel supplies roughly 12 hours of continuous operation in the energy‑intensive grande sonnerie mode. Remarkably, all of this mechanical complexity and acoustic innovation is contained within a case measuring just 43 mm in diameter and 14.08 mm in height, a compact achievement that balances intricate functionality with contemporary expectations for size and efficiency.

The 70‑hour main power reserve is remarkable for a watch of such mechanical complexity, particularly given its relatively high balance frequency. The L.U.C 08.03‑L runs at 4 Hz (28,800 vph)—a rate more commonly found in sports watches and unusually fast for a complication of this calibre. By refusing to compromise on performance and maintaining the same exacting standards expected of any contemporary wristwatch, the L.U.C Grand Strike preserves outstanding chronometric reliability.

That accuracy is reinforced by the time‑setting system, which includes a stop‑seconds function. Pulling the crown into the setting position halts the small seconds hand, enabling the wearer to set the time precisely to the second and fully exploit the movement’s timing potential as shown on the dial.

Beyond its precision and display, the L.U.C Grand Strike was engineered for longevity. From the prototype phase onward, Chopard’s in‑house testing subjects the sonnerie to 62,400 activations—half in each sonnerie mode—through an accelerated regimen that simulates five years of wear in just three months. During this period the minute repeater is also engaged repeatedly via the crown pusher—3,000 activations—to confirm the movement’s endurance. Across the entire testing cycle the sapphire crystal gongs are struck more than half a million times, a testament to the robustness of the L.U.C 08.03‑L calibre.

Although rooted in Chopard’s long watchmaking heritage, the Grand Strike’s essence is innovation. To refine its signature chime, Chopard collaborated with Geneva’s Haute Ecole du Paysage, d’Ingénierie et d’Architecture (HEPIA) to study the acoustic behaviour of its system, identifying three principal differences that distinguish sapphire crystal gongs from traditional steel ones.

First is the monobloc construction. Where conventional chiming watches mount polished steel gongs with a round cross‑section to the movement by screws—an arrangement that transmits vibrational energy indirectly and loses acoustic power through attachments, the movement and the case—Chopard machines the gongs and dial from a single piece of sapphire crystal. When struck, these gongs vibrate together with the dial, directing sound outward and avoiding energy loss through the movement or case, which yields a clearer, purer tone.

Second is the geometry of the gongs. Rather than the circular cross‑section of steel gongs, the sapphire gongs use an orthogonal (square) profile. This increases the contact area between hammer and gong and alters the way vibrational energy is transmitted. The right‑angled edges guide sound into distinct vibrational modes, producing a layered, textured chime that is both harmonious and richly nuanced. Third is the material itself. The monocrystalline structure of sapphire crystal produces a sound that is at once delicate and powerful—brilliant and resonant in a way steel cannot match. Its exceptional hardness (second only to diamond) prevents deformation, preserving tonal consistency over time; Chopard calls this signature timbre the Sound of Eternity.

The L.U.C Grand Strike’s notes are tuned to a C♯–F natural chord, an interval perceived as conveying stability and unity. To support and protect this exceptional acoustic performance, Chopard filed five new patents for the movement. Two focus on user safety, permitting the chiming mechanism to be engaged at any time without risk to the movement and enabling mode changes without disturbing the time display—features designed for intuitive everyday use.

The remaining three patents target performance. One introduces an energy‑efficient clutch that lowers the torque required to start the sonnerie, thereby extending the sonnerie barrel’s autonomy. Another prevents sonnerie activation when torque is insufficient, avoiding incomplete strikes. The final patent rethinks the striking hammers’ geometry to alter their moment of inertia, reducing the risk of damaging impacts to the sapphire gongs in the event of a shock. These protective measures were implemented without compromising the purity and quality of the chime.

Every element of the L.U.C Grand Strike has been conceived to showcase Chopard’s watchmaking mastery and refined aesthetic, marrying technical prowess with wearable elegance. Its proportions are deliberately comfortable, yet the watch is rich with discreet details that enhance the experience of wearing it. Rather than hiding its complexity, this chiming watch celebrates it. The absence of a conventional dial exposes the movement, inviting the wearer to admire the intricate mechanics that define Haute Horlogerie.

To balance the forward‑looking sapphire crystal chiming system, the movement’s plates and bridges are crafted from traditional German silver (maillechort). This historic alloy, prized for the warm patina it acquires over time and its sensitivity to the oils of the skin, demands exceptional care in finishing—an attribute connoisseurs will immediately appreciate. The casework is equally considered: satin brushing on the case middle reveals the soft glow of white gold, while the bassiné profile, subtly rounded toward the caseback, allows the watch to sit fluidly against the wrist. Solid gold hands and hour markers add a final note of refinement. Though visually similar to gold‑plated parts, their solid construction signals an uncompromising approach to material quality at Chopard Manufacture.

Karl‑Friedrich Scheufele sums up the philosophy behind the piece: Chopard builds watches that fuse innovation with tradition. The case was reshaped around the movement born of decades of expertise, and every effort was made to ensure the Grand Strike is a pleasure to wear—from hand‑finished surfaces that catch the light to the softly contoured case and interchangeable straps that adapt to personal taste. Collectors will recognise the careful proportions and finishes chosen to honour the heritage of chiming watches.

Music and watchmaking share a common spirit: both elevate, inspire and communicate the sublime through rules that are at once mathematical and elegant. Chiming watches, which unite these disciplines, are rightly regarded as the apex of horological craft. As Chopard’s sonnerie work enters its third decade, the L.U.C Grand Strike fulfils the promise first signalled by the L.U.C Strike One in 2006. Its chime is a rare achievement—ephemeral yet unforgettable, immediate and timeless.

Looking ahead to 2026, Chopard Manufacture will celebrate thirty years since establishing its in‑house movement workshops at Fleurier, a legacy that began with the 1996 debut of the calibre L.U.C 96.01‑L. Over three decades the ateliers have evolved into a full Manufacture, mastering every stage of production—from base calibres to complex movements, from meticulous hand finishing to chronometer certification, and from component machining to artisanal decorative techniques. This journey includes pioneering advances such as sapphire crystal gongs and a commitment to responsibly sourced materials. The L.U.C collection today stands as proof of what sustained vision, family stewardship and exacting standards can achieve in Swiss watchmaking.