The Bell & Ross BR-X3 Tourbillon Micro-Rotor isn’t built for quick time checks, it’s built to expose every mechanical secret. Crafted in transparent sapphire and engineered around a flying tourbillon and micro-rotor, this limited 25-piece creation turns high-watchmaking into a visible architecture. It reimagines Bell & Ross not as cockpit instrument makers, but as sculptors of mechanical space.
A case built to disappear
You can see right through it. Bell & Ross built the 40mm case with steel and sapphire crystals on the front and back, held together by four screws. This construction method allows the case and movement to work together rather than existing separately. Sapphire is notoriously difficult to machine due to its hardness, but here it serves a specific purpose: revealing the BR-CAL.389 movement inside.
The case is only 9 mm thick. This is remarkably slim for a watch that houses both a flying tourbillon and a micro-rotor automatic winding system. The sapphire components have an anti-reflective coating that maximizes visibility of the internal mechanical components.
A design language born from geometry
Creative director Bruno Belamich drew inspiration from two unlikely sources: Piet Mondrian’s geometric abstraction provided the orthogonal lines and spatial divisions. Charlotte Perriand’s architectural work contributed the refined functionality. Together, these influences create a strict grid pattern that structures the entire movement.
The skeletonized architecture follows this grid pattern precisely. Horizontal and vertical lines divide the mechanical space into precise sections. Twenty-six rubies punctuate the composition with their red glow. The time display is in a small, offset position at 2 o’clock and features only hours and minutes on a smoked sapphire subdial.
An in-house movement with lofty ambitions
The BR-CAL.389 caliber combines two significant complications. A flying tourbillon sits at the 5:30 position, rotating once per minute to counteract the effects of gravity on the balance spring. Abraham-Louis Breguet invented this mechanism at the turn of the 19th century, and it remains one of the most respected achievements in horology.
The micro-rotor provides automatic winding while maintaining the watch’s slim profile. Traditional rotors sit above the movement and add thickness. This miniaturized oscillating weight, however, sits within the movement plane. Despite the spatial constraints, the configuration delivers 58 hours of power reserve.
However, micro-rotors present inherent challenges. They generate less rotational inertia than full rotors, so they’re less efficient at winding the mainspring. They are also more susceptible to external shocks that can disrupt rotation. However, the BR-CAL.389 overcomes these limitations through careful engineering.
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Finishing that serves function
The movement receives traditional haute horlogerie treatment. The bridges have brushed finishes with linear reflections. The edges have polished bevels that precisely define contours. The rhodium-plated hands stand out against the skeletonized backdrop.
Bell & Ross has eliminated excess decoration. The grid structure provides visual organization without additional ornamentation. The fumé sapphire dial section is small and unobtrusive. The gray alligator strap is attached with a folding steel buckle that has alternating polished and satin finishes.
Exclusivity through technical mastery
Only 25 will be made. The watch has the reference number BRX3M-TRB-ST/SCR and is water resistant up to 50 meters. This piece represents Bell & Ross’s third level of sophistication, following their iconic square instruments and skeleton models.
Bell & Ross built its reputation on legibility, functionality, and precision derived from cockpit instrumentation. The BR 01, launched in 2005, featured the signature circle-within-a-square design. This new piece moves beyond those professional codes toward pure mechanical exhibition.
A watch for collectors of ideas, not just objects
You’re getting a watch that prioritizes movement visibility over practical timekeeping. Thanks to its transparent case construction, you can observe the tourbillon’s rotation and the micro-rotor’s motion throughout the day. The strict geometric layout will appeal to those who appreciate horology and design theory.
Despite the complex mechanics inside, the 40mm dimensions keep it wearable. The 9mm thickness easily slides under most shirt cuffs. The weight remains reasonable thanks to sapphire components that replace solid metal.
When mechanics become the message
Bell & Ross positions this watch as haute horlogerie rather than a professional tool. The time display is intentionally minimized. Reading the hours and minutes requires looking at the offset subdial rather than the center of the watch. The movement becomes the focal point.
The price reflects the limited production and complexity involved. Creating sapphire cases with this level of transparency requires specialized equipment and expertise. The dual-complication, in-house movement adds significant value. This timepiece is targeted towards collectors who prioritize mechanical achievement over everyday practicality.
This watch is part of Bell & Ross’s expanding range of products, which extends beyond aviation instruments. Bell & Ross now operates in over 80 countries through 600 retailers and 25 boutiques. Bell & Ross maintains partnerships with La Patrouille de France and the Rafale Solo Display, thereby keeping their aeronautical roots visible.