Timekeepers Club / September 21, 2021

Armin Strom Gravity Equal Force Ultimate Sapphire

Armin Strom, the Swiss luxury watch manufacturer known for its edgy, eye-catching transparent mechanics, has just launched a rare and stunning new version of its milestone Gravity Equal Force timepiece. With its off-center grey-toned sapphire dial, the strikingly cool monochrome watch offers an extraordinary view of the exquisitely-finished manufacture movement and further enhances the brand’s reputation for its irrepressible, exuberant independence. 

Armin Strom’s Gravity Equal Force has made quite an impression on watch enthusiasts since it was first launched in 2019. And for good reason: it is the world’s first automatic watch with constant force transmission, which results in consistent power delivery to the balance. In short, it means that the watch always delivers flawlessly constant precision. Its ASB19 caliber offers a power reserve of 72 hours.

The timepiece stands out not only with its groundbreaking technology but by a design and craftsmanship that set it apart from every other watch. With the launch of the Gravity Equal Force Ultimate Sapphire, Armin Strom has reinforced its commitment to the transparent mechanics that have been generating an industry-wide buzz since the brand’s beginnings. The watch is distinguished in equal part by its technical and aesthetic innovations:

  • The movement’s black plate guilloche pattern was created by hand by the celebrated Finnish watchmaker Kari Voutilainen, a close friend of Armin Strom’s founders. 
  • The off-center grey-toned sapphire dial offers an unobstructed view of the fascinating mechanics inside the case and emphasizes the brand’s passion for transparent mechanics, which are at the core of its design philosophy.
  • The bridges are coated with dark grey ruthenium; the barrel and the micro rotor are coated with rhodium.
  • The Gravity Equal Force’s ASB19 movement includes a “stop work” mechanism that prevents the mainspring from fully unwinding, thus leveraging only the part of the mainspring’s unwinding process that can deliver power most consistently. 
  • The steel hands with Super-LumiNova® filling are manufactured by Armin Strom and like all of the visible parts of the movement, are meticulously hand-finished in-house

Presented in a classic 41 mm stainless-steel case, the Armin Strom Gravity Equal Force Ultimate Sapphire comes with a black fabric strap with light grey stitching, subtly maintaining the watch’s resolutely cool monochrome color scheme. 

Claude Greisler, Armin Strom’s co-founder and head watchmaker, points out that the new watch’s cool, understated monochrome design will appeal to fans of the brand’s design philosophy: “We’ve re-imagined the Gravity Equal Force to more fully embrace our passion for transparent mechanics, while adding complementary aesthetic complexity that enhances the watch’s special visual impact.

Serge Michel, founder of Armin Strom adds: “The special version of our GEF was extremely well received in early presentations to collectors so we hope to be able to produce 30 more watches next year in addition to the 15 from this year. That may, however, be too ambitious because our capacities are limited and it always has to be a rare piece, which is why we have decided that half of all future productions will be placed on a first-come/first-served waiting list for those who inquire via our website.

The Armin Strom Gravity Equal Force Ultimate Sapphire: exquisite in-house design and production

This breathtaking new Gravity Equal Force timepiece was designed and produced in-house at the brand’s manufacture in Biel. Like every Armin Strom watch, its movement has been assembled twice. After its first assembly, the movement was painstakingly disassembled and each individual part was cleaned, dried, reassembled and lubricated before being meticulously regulated, tested, and returned to the case. 


The Gravity Equal Force: redefining the horological landscape

Launched in 2019, the milestone timepiece demonstrates Armin Strom’s core principle: to bring innovation to every watch. It combines the brand’s celebrated passion for transparent mechanics and its distinctive design as well as its commitment to redefining the horological landscape with every new product.


The Gravity Equal Force Ultimate Sapphire will be available from October 2021 in a limited quantity of 15 pieces for 2021. Due to the limited production capacity, the special timepiece will be available subsequently in a very small number of pieces per year. 

Technical specifications: 

Armin Strom Gravity Equal Force Ultimate Sapphire

Reference: ST21-GEF.SA.VE.M.30

Limited edition of 15 pieces


  • Material: Stainless steel
  • Diameter: 41 mm
  • Thickness: 12.65 mm
  • Glass: Sapphire crystal and case back with anti-reflective treatment
  • Water-resistant to 30 meters

Dial and hands

  • Dial: Grey toned off-center sapphire dial with subdial
  • Hands: Manufactured by Armin Strom, steel with hand finishing and Super-LumiNova® filling


  • Armin Strom manufacture Caliber ASB19
  • Automatic winding with micro rotor, Geneva-drive equal force barrel, offset display with subdial seconds
  • Regulating system: Balance wheel with 4 regulating screws
  • Dimensions: 35.52 mm x 11.67 mm
  • Frequency: 25,200 vph (3,5 Hz)
  • Finishing: Hand-finishing to the highest quality level
  • Number of jewels: 28
  • Number of components: 202
  • Power reserve: Geneva stop-work limited to 72 hours


  • Hours, minutes, seconds, power reserve indicator

Strap and buckle

  • Delivered with a black fabric strap with light grey stitching and stainless-steel double folding clasp


  • CHF 22'900
  • EUR 20'000
  • USD 22'900

For more information, please visit


Leave a comment

You must be logged in to post a comment Login / Sign up