The Gravity Equal Force Ultimate Sapphire Salmon represents a confident statement in Armin Strom’s ongoing exploration of micro-rotor architecture combined with innovative constant force delivery. Released as a limited annual production of twenty-five pieces, this 41 mm stainless steel timepiece arrives as a refined evolution of the GEF design, distinguished principally by its salmon-coloured PVD-coated mainplate and the accompanying grey nubuck leather strap. Where earlier iterations of this collection have garnered attention for technical innovation alone, this edition invites contemplation of how colour and surface treatment can alter one’s relationship with a mechanism fundamentally unchanged in its engineering aspirations.
The Dial: Transparency as Design Statement
The dial construction demands immediate attention, for it abandons the conventional opaque surface in favour of a grey-toned off-centre sapphire crystal that serves as both protective element and compositional device. This transparent approach transforms the dial into something approaching a window, with the subdial occupying a decentred position that creates visual rhythm across the surface. The sapphire crystal has received anti-reflective treatment on its inner surfaces, a practical consideration that prevents the optical confusion that might otherwise arise from viewing the movement beneath at oblique angles.
The hands themselves represent a refined expression of functional clarity. Rhodium-plated and facetted with careful polishing, they cut through the transparent field with definition whilst remaining sufficiently slender that they do not overwhelm the view of the movement. Both hour and minute hands carry Super-LumiNova filling, though the quantity remains modest given their proportions, a pragmatic acknowledgement that legibility through luminescence depends substantially upon hand size rather than lume application alone.
Constant Force Through Patented Architecture
Beneath the transparent dial resides the Calibre ASB19, an in-house developed automatic movement that distinguishes itself through its patented approach to constant force delivery. The innovation centres upon a stop-work declutch mechanism integrated directly within the mainspring barrel, a structural solution that isolates the most linear segment of the mainspring’s power curve and restricts energy delivery to precisely this optimised range. This engineering prevents the significant torque variation that characterises conventional mainsprings, where the spring delivers substantially higher force at full wind and diminishing force as it unwinds. By mechanically limiting the usable arc of the mainspring, Armin Strom has achieved more consistent power transmission to the balance wheel across the full 72-hour power reserve.
The movement itself measures 35.52 mm in diameter by 11.67 mm in height, housing 202 individual components with 28 jewels distributed throughout the gear train and escapement. It beats at 3.5 hertz (25,200 vibrations per hour), a frequency that balances amplitude against energy efficiency whilst remaining well within conventional horology parameters.
The decoration reflects Armin Strom‘s commitment to what the manufacture terms the Science of Movement, a philosophy that rejects the notion that mechanical finishing should be confined to hidden surfaces. The mainplate itself presents the most visually striking element: a salmon-coloured PVD coating applied to steel, upon which sits a beautiful hand-guilloché pattern executed by Kari Voutilainen Atelier, the celebrated independent Finnish watchmaker. This rose engine work creates a surface of considerable depth, with the pattern catching light differently depending upon viewing angle and ambient illumination. The guilloché neither dominates nor retreats; it occupies precisely the visual weight one would expect from a component viewed directly through the dial.
The bridges carry bevelled and polished edges throughout, whilst their visible surfaces receive treatment appropriate to their structural purpose. Circular graining, known as perlage, adorns certain surfaces, creating a soft textural field that provides visual interest without introducing excessive visual complexity. Geneva stripes, parallel linear decorations, appear where coherent with the movement’s geometry, their execution demonstrating a consistency that suggests machine assistance followed by hand-finishing to achieve uniform appearance.
The black polished screws punctuate the movement with functional punctuation, their slender proportions and perfect flatness suggesting careful hand-finishing after the initial polishing operations. The balance wheel itself carries four regulating screws, permitting fine adjustment to rate once the movement has been cased. The hairspring, sourced from respected suppliers within the horological supply chain, has been balanced and poised to deliver the enhanced isochronism that the constant force mechanism’s consistent power delivery enables.
Armin Strom assembles each movement twice, an unusual manufacturing approach that reflects the manufacture’s quality control philosophy. The first assembly permits the watchmakers to test all functions and verify accuracy across positional variations, after which the movement is disassembled, components are inspected and refined if necessary, and the assembly is performed a second time before casing.
Compact Proportions with Refined Execution
The case measures 41 mm in diameter, 12.65 mm in height, with a lug-to-lug distance of 48.09 mm, proportions that position the watch firmly within contemporary sizing conventions whilst maintaining sufficient presence on the wrist. The stainless steel construction provides the durability essential for a watch intended to be worn rather than observed solely upon inspection.
Both the sapphire crystal and case back receive anti-reflective treatment on their inner surfaces, a detail that permits unobstructed appreciation of the movement’s architecture without the optical peculiarities that arise from untreated sapphire. The case itself carries the water resistance rating of 3 atmospheres, suitable for incidental contact with water but not for submersion or shower environments, a specification entirely consistent with a timepiece designed primarily for wrist wear rather than aquatic contexts.
The grey nubuck leather strap arrives pre-paired with the watch, its matte, velvety surface providing tactile contrast to the polished and brushed steel of the case. The grey stitching matches both the strap itself and the overall chromatic palette, creating a cohesive aesthetic field. A stainless steel folding clasp secures the strap, its mechanically simple but effective design reflecting the manufacture’s preference for functional simplicity over decorative elaboration.
Colour as Catalyst
The Gravity Equal Force Ultimate Sapphire Salmon arrives at a moment when independent watchmaking increasingly emphasises technical innovation at the expense of accessible colour palettes. By introducing this salmon-toned iteration alongside its established blue version, Armin Strom invites collectors to reconsider how surface colour can alter the visual character of a fundamentally identical mechanical package. The salmon hue imparts warmth to what might otherwise read as a predominantly cool-toned design, whilst the nubuck strap compounds this shift in character.
What emerges is not a revolutionary redesign but rather a thoughtful exploration of how the GEF architecture performs across different chromatic territories. For collectors drawn to Armin Strom‘s transparent dial philosophy and constant force engineering, this annual limited production of twenty-five pieces (priced at CHF 27,500) represents a distinct entry point to the collection. The manufacturing rigour, decorative language and technical achievements remain identical to earlier iterations; the salmon treatment functions principally as a gateway to appreciation of the movement architecture itself. In this capacity, it succeeds entirely, offering colour without compromising the transparency that defines the design’s fundamental strategy.
