Shopping Cart

Armin strom sets the tone in the realm of transparent mechanics with the Gravity Equal Force Ultimate Sapphire Purple

MAY 06 2024    |    Novelties

Armin Strom fuses masterful mechanics with a bold chromatic twist, unveiling its latest Ultimate Sapphire Edition. The iconic Gravity Equal Force now sports a striking purple guilloché-engraved mainplate by Kari Voutilainen. 

Armin Strom’s System 78 collection represents the independent manufacture’s purest expression of innovative haute horlogerie. Within it, the classical codes of watchmaking are revisited to bring about new functions and solutions, while also expressing the brand’s unique aesthetic sensibilities. With an emphasis on transparency, as well as highlighting kinetic elements, the Gravity Equal Force stands out as a technical tour-de-force with an instantly recognisable look – outstanding in form and function, finished by meticulous hand decoration. Now, with the new ‘Purple’ Ultimate Sapphire Edition, Armin Strom is doubling down on integrating vibrant chromatic hues with exceptional mechanics.

Let it reign: Gravity Equal Force Purple

At once regal and electric, the latest edition of the Gravity Equal Force features a colour Armin Strom has never used before. Its base plate boasts a guilloché engraved motif with a barley grain pattern, expertly handcrafted in the atelier of acclaimed independent watchmaker Kari Voutilainen using a traditional rose engine lathe. The striking purple colour is applied using a 3D PVD process, which reflects a wide spectrum of tones as it shifts with the light. Making this edition even more outstanding, the small off-centred dial is crafted from transparent sapphire crystal, which is reserved exclusively for the Gravity Equal Force’s Ultimate Sapphire Editions. The crowning glory is a light grey nubuck leather strap with purple stitching and keepers. The Gravity Equal Force Ultimate Sapphire Purple is limited to a run of 25 pieces per year.

 

Automatic: redefined

The Gravity Equal Force stands out as the first automatic watch endowed with an equal force transmission integrated directly in the mainspring barrel - a patented mechanism by Armin Strom. It provides consistent power transmission to the regulating organ, ensuring unwavering precision throughout the watch’s autonomy. The power reserve indicator forms part of the barrel, which is entirely visible from the dial side, opposite the micro-rotor with a unique click system featuring two springs for better winding efficiency.

Also this latest creation, part of Armin Strom’s perpetual quest for superior chronometric performance, was entirely developed, manufactured and decorated within the walls of the Bienne-based manufacturing site. Like all Armin Strom watches, the Gravity Equal Force Purple’s movement is assembled a first time to ensure it is in perfect working order and that it meets the brand’s exacting decorative standards, then taken apart and assembled a second time when it is ready to be cased in its final form. 

 

Putting the ‘haute’ in ‘horlogerie’

What separates a mere tool from a work of art is craftsmanship. Like a canvas for artistic expression, superlative hand-finishing applied by specialised watchmakers and seasoned artisans can be appreciated throughout the Gravity Equal Force and its many proudly exposed layers and components. Polished bevels (anglage) on the bridges, black polished screws, polished countersinks, perlage and various types of graining, be it straight or circular, as well as Geneva stripes on the three-quarter bridge visible through the case’s back.

One of the Gravity Equal Force’s most distinctive elements is the triplet of dark grey ruthenium-plated bridges that occupy the right-hand portion of the open display. Inspired by the finger-style bridges found in pocket watches, it takes up to an entire day for these bridges to be embellished by hand. First, the undersides are given a matt finish, after which the sides are given a straight-graining finish by carefully sliding them on an abrasive paper to produce continuous, shimmering fine lines. Then, the inner and outer chamfers of the bridges are bevelled with increasingly fine files and then finished with a flash polish using locally sourced gentian wood to remove even the finest lines. Finally, a straight-graining finish is applied to the top side for ultimate radiance.

Armin Strom : 15 years in the science of movement

In 2008, longtime friends and partners Serge Michel and Claude Greisler took the reins at Armin Strom and founded its very own manufacture in the watchmaking town of Biel in 2009. Just one year later, the duo presented their very first watch with a movement designed and manufactured in-house. Over the following years, Armin Strom would become a truly integrated and self-sufficient manufacture, creating 17 exclusive calibres and developing several world firsts in the domain of watchmaking. In 2016, it introduced the Mirrored Force Resonance, a game-changing resonating dual regulator developed for maximum chronometric precision with a captivating oscillation mechanism on the dial-side of the watch. In 2019, Armin Strom reinvented the automatic watch movement with the Gravity Equal Force, the first automatic watch to feature an equal force transmission mechanism within the barrel that had previously been found only in pocket watches. Today, Armin Strom stands out as a leading force of creative, independent watchmaking, with its own distinct design language and exceptional attention to detail highlighted by hand-finishing all its creations. 2024 promises to be a year full of surprises, and the best is yet to come…

 

Gravity Equal Force Ultimate Sapphire Purple

Technical specifications

                   

Indications     Hours, minutes, seconds, power reserve indicator
Movement     Armin Strom manufacture Caliber ASB19
      Automatic winding with micro rotor, Geneva-drive equal force barrel, offset display with subdial seconds
Main plate   purple PVD plate with guilloché pattern by Kari Voutilainen
Regulating system   Balance wheel with 4 regulating screws
Power reserve   Geneva stop-work limited to 72 hours
Dimensions   35.52 mm x 11.67 mm
Frequency   3,5 Hz (25,200 vph)
Finishing   Hand-finishing to the highest quality level
Jewels   28
Number of components   202
Case   stainless steel
    Sapphire crystal and case back with anti-reflective treatment
Diameter   41 mm
Height   12.65 mm
Water resistance   3ATM
Lug-to-Lug   48.09 mm
     

Dial

 

Grey toned off-center sapphire dial with subdial

Hands  

Faceted polished hands and Super-LumiNova® filling

Strap   Delivered with a grey nubuck leather strap with purple stitching and keepers
Width lugs/buckle   20/18 mm
Buckle   Pin buckle or folding clasp available in stainless
Reference   ST24-GEF.SA.AC.M.A7.FC
Limited production   25 pieces per year

 

 

                                           

                                            

 


Related Articles

APRIL 01 2026    |    Watches and Wonders 2026

The Architecture of Two Worlds: Chronoswiss Unveils the PULSE GMT Collection

Chronoswiss marks a definitive leap into the future of independent watchmaking with the introduction of the PULSE GMT, a collection that represents one of the most progressive chapters in the brand's history. Inspired by the mechanical spirit of the 1999 Tora icon, this new series redefines traditional design codes through a radically modern lens while maintaining the brand's independent spirit. The collection is built specifically for global travelers and collectors who move between continents and time zones, requiring a sophisticated mechanical companion.

The PULSE GMT features a bold, sculptural case construction that seamlessly integrates the first full metal bracelet in Chronoswiss history. This architectural approach ensures a unified presence on the wrist, blending the iconic onion crown and coin-edge bezel with contemporary lines. Whether crafted from high-strength Grade 5 Titanium for daily wear or solid 18-carat 5N Gold, the 41mm case offers a powerful physical and visual statement.

At the heart of the collection beats the Manufacture Caliber C.6002, an automatic movement developed exclusively with La Joux-Perret. This dedicated mechanical construction provides a true dual-time display, featuring a 24-hour second time zone on the left and a 12-hour home time on the right, all unified by central minutes and seconds. With a 55-hour power reserve and water resistance up to 10 bar, the movement is designed for movement and mechanical clarity.

The collection showcases the height of Lucerne craftsmanship through two distinct dial interpretations. The Silver Guilloche edition celebrates pure mechanical texture with hand-guilloché patterns cut on century-old machines, while the Enamel Sky Gold features the rare art of paillonné enamel. This demanding craft embeds gold stars within layers of translucent fire enamel over a guilloché base, creating a celestial display designed to last for centuries.

View Watch Gallery  
Image 1  Image 2 Image 3  Image 4  Image 5  Image 6   
View More
MAY 20 2026    |    Novelties

Celestial Contrast: Armin Strom Dual Time GMT Resonance Aventurine

Armin Strom presents a new interpretation of its Dual Time GMT Resonance, distinguished by a dial crafted from aventurine—a material that captures the richness and mystery of a star-filled sky. Formed through a meticulous process that blends centuries-old glassmaking with modern precision, aventurine reveals a surface alive with light. The result is a dial that evokes a night sky in motion, creating a refined contrast with the architectural symmetry of the resonance movement. This celestial texture is enhanced by the warm tones of the movement: the rose gold-coloured mainplate adds depth beneath the dial-side display, while rose gold-coloured hands and applied indexes introduce clarity and visual identity. Together, these elements create a balanced interplay between cool luminosity and warm mechanical presence. Housed in a 39 mm stainless steel case and paired with a dark grey alligator strap, the Aventurine edition offers a contemporary and restrained frame, allowing the dial's dimension and the movement's symmetry to take centre stage.

Resonance Across Time Zones
Powering the watch is the manual-winding manufacture calibre ARF22, entirely designed, developed and produced in-house. Its patented resonance clutch—a signature Armin Strom innovation—synchronises two independent regulating systems, allowing both balance wheels to oscillate in perfect harmony. This constant interaction elevates chronometric stability, transforming a rare physical phenomenon into a practical advantage. Each time zone features its own hours, minutes and day/night indicator, offering intuitive functionality for travellers. Operating at 3.5 Hz (25,200 vph) with a 42-hour power reserve, the ARF22 unites scientific ingenuity with everyday usability.

Finishing in Depth
Visible through sapphire crystals on both sides, the movement reveals Armin Strom's signature open-worked architecture and hand-finishing. The rose gold-coloured mainplate establishes a warm, luminous foundation on the dial side, while matching gear-train bridges on the reverse side echo this tone, creating a cohesive visual language. This harmony of colour and structure accentuates depth and contrast, reinforcing the three-dimensional expression of the calibre and the brand's commitment to the Science of Movement. On the dial side, the mirror-polished balance bridge, finished with hand-bevelled edges, stands out as a focal point, its steel surface catching the light in striking counterpoint to the warm rose gold-coloured mainplate beneath. Rhodium-coated and steel components introduce a refined metallic grey tone, balancing the overall composition. Additional hand-polished bevels, black-polished elements, circular graining and perlage enrich the composition, while the reverse side features Côtes de Genève, further emphasising the movement's refinement. As with all Armin Strom timepieces, each watch is assembled twice to ensure both mechanical precision and finishing excellence.

The new Dual Time GMT Resonance Aventurine is offered in a strictly limited edition of 15 pieces.

 

View Watch Gallery
Image 1

Image 2
Image 2
Image 2
Image 2
Image 2
 
View More
APRIL 07 2026    |    Watches and Wonders 2026

The HM Pietersite: A Tribute to the Spirit of Exploration and the Art of the Ultra-Thin

Arnold & Son presents two new evocative versions of its ultra-thin HM model, featuring dials crafted from Namibian pietersite. Often called the "stone of storms," this decorative mineral belongs to the chalcedony family and was first discovered by Sid Pieters in the early 1960s. Each unique dial displays delicate, swirling patterns that recall the turbulent skies and foaming waves of Cornwall, the English birthplace of founder John Arnold. This design pays tribute to the ingenuity of the legendary watchmaker while celebrating the spirit of those who maintain their course in a challenging world.

The designation "HM" was intentionally chosen to reflect the watch's focus on displaying only hours and minutes, while simultaneously serving as a historical nod to the British Royal Navy. In naval tradition, HM stands for "His or Her Majesty’s," a title that appeared in the 17th century and was later formalized as HMS. By transposing this reference to watchmaking, Arnold & Son connects the precision of modern horology with England's maritime history, specifically the era when John Arnold’s marine chronometers enabled the exploration of new lands.

Encased in a choice of 18-carat red gold or stainless steel, the HM Pietersite is a masterpiece of elegance and restraint. The case measures a refined 39.5 mm in diameter with a remarkably slim profile of just 7.82 mm. To complement the dreamlike, diaphanous patterns of the pietersite dial, the timepiece is paired with a matte ink-blue alligator leather strap and a traditional pin buckle crafted from the same metal as the case. These limited editions are produced in extremely small quantities, with only 8 pieces available in red gold and 18 in steel.

At the heart of this timepiece lies the ultra-thin, in-house A&S1001 manual-winding calibre. Visible through a sapphire crystal case back, the movement is a showcase of luxury finishing, featuring a rhodium-plated main plate with circular graining and bridges adorned with radiating Côtes de Genève. Despite its slender height of only 2.70 mm, the movement offers exceptional performance with a generous 90-hour power reserve. Every detail, from the snail-finished wheels to the blued screws with polished heads, reflects the most exacting standards of Swiss watchmaking.

View Watch Gallery  
Image 1  Image 2 Image 3  Image 4       
View More
APRIL 29 2026    |    Novelties

A Splash of Fresh Green: Moritz Grossmann Debuts the TEFNUT Silver-Plated by Friction Anniversary Watch

The year 2026 marks a historic milestone for the Moritz Grossmann manufactory in Glashütte, as it celebrates the 200th birthday of its visionary founder and namesake, born on March 27, 1826. A genius watchmaker, scientist, author, and initiator of the German Watchmaking School, Grossmann profoundly shaped the craft of horology and the fate of his hometown. Rather than merely imitating historical concepts, the modern manufactory honors his legacy by blending his cutting-edge philosophy with modern engineering. This dedication to technological perfection and exceptional aesthetics cements its place among the world's elite elite watchmakers.

To commemorate this bicentennial occasion, the brand has unveiled its third anniversary special edition: the TEFNUT Silver-Plated by Friction. Debuting on April 29, 2026, this launch presents an exclusive premiere for collectors—the very first time that the sleek TEFNUT model is made available in a stunning 750/000 yellow gold case, alongside a 750/000 white gold version. Both variations pay homage to their heritage by incorporating an "1826" engraving on the balance cock and showcasing a vintage 1875 "M. GROSSMANN" logo on the dial.

At the heart of the timepiece lies the ultra-flat manufactory calibre 102.1, a hand-wound movement measuring just 4 mm in height and 26 mm in diameter. This compact footprint enables the watch to retain its remarkably elegant, low-profile silhouette. The calibre embodies classic Grossmann pillar movement architecture with a 3/5 plate, incorporating his signature raised gold chatons, an optimized mainspring barrel with bilateral jewel bearings, and a stepped balance cock with a micrometer screw. Each component is meticulously hand-finished to ensure absolute technical and visual distinctiveness.

The defining aesthetic feature of this model is its striking dial, which boasts a rare "silver-plated by friction" finish. Executed entirely by hand in the brand's ateliers, a master artisan brushes a specialized paste of silver powder, salt, cream of tartar, and water onto the brass surface to create a velvety, fine-grained texture that beautifully diffuses light. To provide a contemporary contrast, the numerals, minute scale, and historic logo are rendered in a vibrant green hue. Hovering above are extraordinarily fine, hand-crafted lance-shaped hands, polished in gold for the yellow gold model and annealed to a brown-violet tone for the white gold edition. Each variation is strictly limited to just 12 pieces worldwide.

View Watch Gallery  
Image 1  Image 2 Image 3  Image 4       
View More
AUGUST 19 2025    |    Novelties

Chronoswiss Celebrates 30 Years of Horological Innovation with the Opus Purple Rain Limited Edition

Chronoswiss celebrates three decades of horological mastery with the launch of the Opus Purple Rain, a bold and limited edition chronograph that reimagines the brand’s iconic skeletonized timepiece. Limited to just 30 pieces worldwide, this anniversary edition marks a milestone in modern independent watchmaking, honoring the legacy of the original Opus while pushing the boundaries of design and mechanical transparency.

First introduced in 1995 by Chronoswiss founder Gerd-Rüdiger Lang, the Opus revolutionized the chronograph landscape by exposing its intricate movement architecture on the dial side—a radical departure from the traditionally closed and utilitarian chronographs of the time. The Opus became a symbol of mechanical artistry and a signature of the brand’s avant-garde spirit.

The Opus Purple Rain carries this legacy into the future with unapologetic flair. Encased in Grade 5 titanium and finished with a radiant purple CVD coating, the watch is both lightweight and visually arresting. Its skeletonized dial, also rendered in ultraviolet hues, reveals the ruthenium-coated Chronoswiss C.741S automatic chronograph caliber, offering a 46-hour power reserve and a full suite of chronograph functions including central seconds, 30-minute and 12-hour counters, small seconds, and date.

Adding to its rebellious character is a white UV-reactive leather strap that transforms into glowing purple when exposed to sunlight—an unexpected and surreal tribute to the energy behind this creation. Signature Chronoswiss elements such as the onion crown, coin-edged bezel, and patented Autobloc screw-in lugs remain intact, anchoring the watch in its heritage while embracing a futuristic aesthetic.

“The Opus Purple Rain is not just a commemorative piece—it’s a statement,” said Chronoswiss CEO Oliver Ebstein. “It embodies the spirit of mechanical transparency and innovation that has defined Chronoswiss for 30 years. This is a watch for those who dare to see how far precision and design can be pushed.”

With only 30 pieces produced, the Opus Purple Rain is destined to become a collector’s treasure—a celebration of the past, a vision of the future, and a mechanical theatre on the wrist. 

View Watch Gallery  
Image 1  Image 2  Image 3  Image 4
View More
ENDLESS DISCOVERY IN YOUR INBOX
Join our mailing list to receive insider updates on our latest collections, invites to private events, and other personalized offerings.