Timekeepers Club / December 15, 2021

Armin Strom Resonance “Zeitgeist” Unique Piece

This extraordinary piece from the independent Swiss manufacture Armin Strom celebrates the fifth anniversary of the brand's resonance technology. Zeitgeist shines the spotlight on Armin Strom's patented Resonance Clutch Spring and its ability to create the most consistent timekeeping. The extraordinary component is a testimony to the brand's ideals and its focus on cutting-edge research and evolution in watchmaking. Zeitgeist marks the next chapter for resonance watches.

Armin Strom's  ingenious  technology  is dramatically  showcased  in the Zeitgeist  by exposing the entire  mechanism.  The  Zeitgeist  elevates  the  patented,  time-tested  and  scientifically- proven Resonance Clutch Spring in a new caliber, giving the technology a facelift and offering an understated  aesthetic  profile.  The  43mm  case  has  been  crafted  from  platinum  and  the movement,  created  in-house  by Armin Strom's specialists,  has been produced  in traditional watchmaking metals including German silver, steel, and brass. The movement is clearly at the center of  this  distinctive  timepiece,  which  offers  minimalist  dial  components and  subtle decoration. Staying true to the concept, the Resonance Clutch Spring and dual balance wheels cantilever off the edge of the movement, drawing the eye to Armin Strom's technical innovation.

We decided to create something unique for this fifth anniversary: a work of art that honors our resonance technology and pays tribute to our roots in skeletonization. Zeitgeist's  movement was painstakingly produced, piece by piece, clearly emphasizes the resonance mechanism. This has never been done before so we're all very excited” says Claude  Greisler,  Armin Strom's Co-Founder and Master Watchmaker.

Resonance technology and the value of consistency

Armin Strom began working with resonance by learning from what Christiaan Huygens, Abraham-Louis Breguet, and Antide Janvier had already discovered centuries ago: resonance is incredibly valuable for consistency, employing scientific principles to regulate rate precision over time. The old masters were engineers who sought to create the most precise and consistent timekeepers for use as scientific instruments, performing tests to discover new principles. The phenomenon of resonance on oscillating systems was successfully applied to horology but has remained very rare due to the difficulty of its implementation.

A brief introduction to resonance in watchmaking

While meeting the challenges of resonance has discouraged most watch brands from trying to apply it, Armin Strom chose to take it on and, true to the brand's spirit, mastered the technology. A brief primer on this phenomenon reveals why it is so difficult.

Resonance  relies  on the ability  of two oscillating  mechanisms  to transmit  vibrational  energy between each other, each affecting the other's rate. When two pendulums or balance wheels are mounted to a common structure,  small vibrations  — literal waves of energy  — are shared through the structure supporting the oscillators. A small force is either added to or subtracted from the opposite oscillator by this energy, averaging their rate by speeding the slower one up and slowing the faster one down.

This continues until both rates perfectly synchronize and hold each other at a consistent rate. Based on Breguet's early experiments,  Armin Strom learned that the most effective way to create resonance was to link the two oscillators via the shared suspension. This allows the vibrations to be passed to the opposite balance wheel in the most direct possible way.

Armin Strom's patented Resonance Clutch Spring

Armin Strom's Resonance  Clutch Spring makes this possible. Crafted from a single piece of steel, the Resonance Clutch Spring is designed to transfer energy between both hairsprings and quickly bring the balance wheels into resonance. Armin Strom's newest generation of resonance is the quickest and most reliable on the market, synchronizing faster than any other watch using resonance.

Thanks to the Resonance Clutch Spring, a flexible suspension connecting the two hairsprings with its balance wheels, all of Armin Strom's Resonance watches are more resistant to shocks or vibrations. Precision and consistency are, of course, the ultimate goals of mechanical watchmaking and resonance plays a crucial role in helping these amazing watches keep time consistently over days, weeks, and months. Armin Strom's goal is a watch that the owner knows will tell the time consistently, day in and day out.

The Resonance Clutch Spring is made of steel and performs more consistently than high-tech materials like silicon, and it withstands temperature fluctuations well. It also makes the Resonance Clutch Spring future proof by using proven materials and modern methods to increase longevity and aid in serviceability. Simply put, Zeitgeist is built to last.

Celebrating five years of Resonance

Armin Strom's  resonance  technology  was launched just seven years after Serge Michel and Claude Greisler transformed the brand into a full manufacture. In that time span, the brand has produced four resonance models, beginning in 2016 with the Mirrored Force Resonance and followed by the Pure Resonance and Dual Time Resonance in 2018 and the world's first resonance chiming watch in 2019, the Minute Repeater Resonance.

To celebrate the fifth anniversary of Armin Strom's ingenious invention, the one-of-a-kind Zeitgeist is the fifth resonance watch introduced by the Swiss manufacture. As Armin Strom Founder Serge Michel points out, “Zeitgeist honors our resonance technology, which plays a very important part in the history and the future of our brand. It stands for our belief in the evolution of watchmaking  and it clearly marks the next chapter in resonance for our manufacture.”

Watch aficionados around the world are looking forward to the next chapter in the Armin Strom story.

Technical specifications: 

Armin Strom Resonance "Zeitgeist"

Reference: PT21-ZG.50

Unique piece 1/1 


  • Material: Platinum
  • Diameter: 43 mm
  • Thickness: 11.55 mm
  • Sapphire crystal and case back with anti-reflective treatment
  • Water-resistant to 50 meters (5 ATM)
  • Width between lugs: 22mm

Dial and hands

  • Dial: 18k white gold “vernis laqué poli” 
  • Hands: Manufactured by Armin Strom — stainless steel with hand finishing


  • Armin Strom manufacture Caliber ARF21 ZG
  • Hand-wound movement
  • Diameter: 36.60 mm
  • Height: 7.00 mm
  • Patented resonance clutch spring, 2 mainspring barrels
  • Regulating system: two independent regulation systems connected by a resonance clutch spring, twin second fly-back
  • Frequency: 25,200 vph (3.5 Hz)
  • Number of jewels: 39
  • Number of components: 260
  • Power reserve of 80 hours 


  • Hours, minutes, twin display of seconds

Strap and buckle

  • Black alligator leather strap and double folding clasp


  • CHF 160'000
  • EUR 150'000
  • USD 170'000

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