Armin Strom Dual Time GMT Resonance Rose Gold

Independent Biel/Bienne-based watchmaker Armin Strom has introduced a new iteration within its Dual Time GMT Resonance collection, presenting the reference RG25.DT.75 in an 18-karat rose gold case. This release marks the first instance of the brand applying this specific precious metal alloy to the 39-millimeter case profile of the Dual Time GMT Resonance line, shifting from the traditional stainless steel or white metal variations previously utilized to house this caliber. The fundamental objective of this collection remains the practical application of physical resonance to stabilize chronometric performance across two independent time zones. By integrating two separate regulating organs connected via a patented clutch spring, the mechanism forces the balance wheels to oscillate in antiphase, actively correcting rate variations caused by positional changes or kinetic shocks. Traditional GMT or dual-time complications typically utilize a single regulating organ and a secondary gear train to display an offset hour, which inherently links the accuracy of both time zones to a single balance wheel. In contrast, the Armin Strom configuration operates effectively as two parallel movements housed within a single chassis, offering true independence for the respective time displays. This structural configuration is a highly specific engineering solution designed to maximize rate stability in a wearable wrist instrument. The new rose gold iteration maintains the exact mechanical architecture of its predecessors while altering the material composition of the external housing, resulting in a distinct visual contrast against the dark, textured dial components.

The Case and Dial

The exterior housing of the Dual Time GMT Resonance is machined from 18-karat rose gold, featuring a diameter of 39.00 millimeters, a case height of 9.05 millimeters, and a lug-to-lug measurement of 44.50 millimeters. This compact profile represents a deliberate sizing strategy by the manufacturer, ensuring the dual-escapement mechanism remains wearable despite the lateral space required by the twin balance wheels and dual gear trains. The transition to 18-karat rose gold from standard base metals introduces a higher specific gravity, which marginally alters the mass distribution of the watch on the wrist while providing a high-polish finish that standard Grade 2 titanium or untreated steel cannot achieve with the same luster. Examining the case geometry reveals a distinct interplay of surface treatments, with a vertically brushed finish applied to the lateral flanks of the case band and the integrated lug sides. In direct contrast, the stepped bezel, the fluted crown positioned at 4 o'clock, and the superior surfaces of the lugs are finished with a high polish, creating clear visual boundaries between the structural elements. The case is fitted with highly scratch-resistant sapphire crystals on both the front and rear apertures, utilizing synthetic corundum that registers a 9 on the Mohs hardness scale. These crystals are treated with specialized anti-reflective coatings to minimize glare and optimize the legibility of the complex dial architecture under direct light sources. The structural integrity of the case construction is tested to a water resistance rating of 5 ATM, making it suitable for standard daily wear but specifically not engineered for submersion or marine environments.

Beneath the primary sapphire crystal, the dial layout is symmetrically structured to isolate the two independent time indications while exposing the complex resonance mechanics situated in the upper hemisphere. The primary dial base is executed in a black gold-colored grenage finish, a traditional frosting technique that involves applying a specialized abrasive paste to the metal surface to create a finely grained, matte texture that disperses light rather than reflecting it. This grenage surface provides a high-contrast backdrop for the twin time-telling sub-dials, which are framed by black azurage chapter rings featuring fine concentric circular engraving that catches ambient light in distinct radial patterns. Applied rose gold-colored indexes, which are faceted and polished to match the rose gold-colored polished hands, indicate the hours and minutes for each respective time zone. Unlike standard GMT complications where the minutes are fixed across all time zones, the dual-movement architecture of this caliber allows the wearer to independently set the minute hands, a critical functional advantage for tracking regions offset by 15 or 30 minutes. Each sub-dial also incorporates a dedicated day/night indicator at the 6 o'clock position, utilizing polished and blackened steel discs engraved with distinct sun and moon motifs to prevent the wearer from confusing AM and PM hours when reading the secondary time zone. The visual hierarchy of the dial is strictly functional, drawing the eye first to the high-polish rose gold hands for time reading, and subsequently to the kinetic motion of the exposed resonance clutch dominating the space between 10 o'clock and 2 o'clock.

The Movement

The operational core of this timepiece is the manufacture Caliber ARF22, a manual-winding mechanical movement designed, developed, and assembled entirely in-house at Armin Strom's Biel/Bienne facility. The architecture of the ARF22 is defined by its dual, independent regulating systems, which are physically connected by the brand's patented resonance clutch spring, a highly specialized component visible directly on the dial side of the watch. This flexible steel spring attaches to the stud carriers of both balance wheels, effectively transmitting the microscopic vibrational energy from one oscillator to the other. Through the physical principle of resonance, first documented in horology by Christiaan Huygens in the 17th century, these coupled oscillators naturally synchronize into antiphase, meaning as one balance wheel swings left, the other swings right. This synchronized state creates an averaging effect on the overall rate; if a kinetic shock causes one balance wheel to accelerate, the opposing balance wheel instantly absorbs the anomaly and pulls the system back into a stable, unified frequency. Operating at a frequency of 3.5 Hz, or 25,200 vibrations per hour, this system provides superior rate stability compared to a single traditional escapement, while the dual gear trains allow for the aforementioned independent setting of the two time zones. The integration of this suspension spring negates the need for traditional aerodynamic or acoustic resonance designs, providing a direct physical link that forces synchronization far more rapidly than passive systems.

The Caliber ARF22 is constructed from 231 individual components, including 40 jewels, and measures 34.15 millimeters in width by 4.92 millimeters in thickness, requiring precise spatial management to fit within the 39-millimeter case chassis. The movement stores its energy in dual mainspring barrels, which are manually wound via the single crown, delivering a guaranteed power reserve of 42 hours when fully wound to maximum tension. The finishing techniques applied to the ARF22 adhere strictly to traditional haute horlogerie standards, requiring hundreds of hours of manual labor at the bench. On the dial side, the structural bridges securing the dual balance wheels feature prominent anglage, with hand-polished bevels catching the light against the brushed top surfaces and black-polished steel components of the clutch system. This black polishing, or speculaire finishing, involves rubbing the steel components on a zinc plate loaded with diamantine paste until the surface becomes perfectly flat, reflecting light uniformly in one direction and appearing completely black from all other angles. Reversing the watch reveals the main movement plates, which are decorated with wide, precisely applied Côtes de Genève stripes running parallel across the horizontal axis of the baseplate. Furthermore, underlying baseplate sections visible beneath the gear train exhibit tight circular graining, or perlage. Crucially, Armin Strom employs a dual-assembly methodology for the ARF22; the movement is completely assembled and regulated to ensure flawless mechanical operation, then entirely disassembled for the final decorative finishes to be applied, and finally reassembled for casing, preventing any accidental scratching of the decorated surfaces during the initial functional testing phase.

The Strap

The Dual Time GMT Resonance Rose Gold is secured to the wrist using a matte grey alligator leather strap. The strap features a large, square-scale pattern typical of premium alligator hides, which provides structural rigidity and a uniform visual texture across the length of the band. Grey stitching runs along the perimeter of the strap, reinforcing the edges and complementing the monochromatic, dark tones of the dial's grenage and azurage finishes without introducing distracting color elements. The strap is fastened utilizing a traditional 18-karat rose gold pin buckle, matching the primary case material and ensuring a secure, straightforward closure method for the wearer.

Pricing and Availability

Armin Strom has positioned the Dual Time GMT Resonance Rose Gold, reference RG25.DT.75, at a retail price of CHF 115,000. Production of this specific 18-karat rose gold iteration is strictly limited to 50 numbered pieces worldwide. This low-volume manufacturing approach directly correlates with the extensive manual labor required to produce the patented resonance clutch spring and hand-finish the 231-component ARF22 caliber. The limited-edition timepiece is currently available through Armin Strom's direct sales channels and select authorized retail partners globally.

Technical Specifications

Case: 18K Rose gold, sapphire crystal front and case back with anti-reflective treatment, 39.00 mm diameter, 9.05 mm height, 44.50 mm lug-to-lug, water resistance to 5 ATM.

Movement: Armin Strom manufacture Caliber ARF22, manual winding, resonance and GMT functions, two independent regulating systems connected by a resonance clutch, 3.5 Hz (25,200 vph), 42-hour power reserve, 40 jewels, 231 components, dimensions 34.15 mm x 4.92 mm.

Dial: Black gold coloured grenage with black azurage chapter rings, applied rose gold coloured coated polished indexes, polished and blackened steel day/night discs.

Strap: Matte grey alligator strap with grey stitching, 18K Rose gold pin buckle.

Price: CHF 115,000.

Reference Number: RG25.DT.75.

Notes: Limited Edition of 50 pieces. Assembled twice to ensure mechanical precision and finish quality.