Gravity Equal Force inspiration and development

Gravity Equal Force represents a drive to constantly improve Armin Strom watches with every model. As a creative watch brand focused on innovation, Armin Strom’s watchmakers and movement engineers routinely research and explore concepts across the horological landscape in search of ways to rethink theory and practice. 

The Gravity Equal Force development began with a desire to deliver equal force to the regulating system. The result was a stop-works declutch mechanism incorporated into the barrel housing ensuring consistent power delivery to the balance and escapement.

Utilizing a Geneva wheel mounted to the barrel housing cover, the rotation of the mainspring barrel is limited to just 9 full turns out of a possible 12.5. This represents the central 72% of the mainspring’s potential torque curve, the flattest and most consistent portion. As the barrel housing unwinds around the arbor, a pin counts off the rotations on the Geneva wheel until it reaches the locked position and prevents further unwinding.

This limit keeps the power delivery to the balance as consistent as possible and the amplitude in optimal range. Once it reaches the upper limit, the declutch mechanism guarantees the slip of the mainspring and allows the micro rotor to turn evenly when fully wound. 

A small declutch lever is attached to the Geneva wheel that marks its rotation and power reserve from full to empty. Sitting atop the barrel cover, the power reserve location will change as the watch is wound, providing some playful variation in the dial display. 

The new stop-works declutch mechanism coincides with a complete reassessment of the mainspring barrel construction. When a U.S. client brought a vintage pocket watch to Armin Strom for repair, it created an opportunity to explore techniques that were common in earlier watches and update them for use in a modern movement.

Upon inspection it was discovered that it bore a motor barrel whose barrel and winding mechanism are constructed opposite that of the standard going barrel. The standard design sees a central arbor often supported by jewel bearings rotating inside the barrel to wind the mainspring. Once fully wound, the arbor remains fixed while the mainspring pushes the barrel housing and so driving the going train.

A typical mainspring barrel doesn’t rotate in a precision jewel bearing but around the arbor, which means higher friction and less precise rotation. The Armin Strom motor barrel design reversed this so that the barrel housing stays locked after winding, allowing the well supported and more precise arbor to rotate and drive the going train.

This simple change goes against at least a century of tradition, yet, when assessed objectively, it is clear that it is a demonstrably better system as it is more precise and stable during operation of the movement. Armin Strom’s watchmakers built on this idea to create an entirely new watch that launches a brand-new collection.

The development of Caliber ASB19 sees continued improvement throughout all the components thanks to the technological advancement of the previous centuries. A new layout combined with improved geometry for the gear teeth and adjustments provides smoother operation and more robust functionality. 

Armin Strom’s focus on innovation and development was kickstarted during the development of its groundbreaking Resonance Clutch Spring and has led to the watchmakers rethinking everything in an attempt to innovate where others stagnate. This isn’t limited to mechanics alone; the entirety of Armin Strom’s design aesthetic is evolving to build a new core moving forward.

The previous openworked display has been replaced by a dial offset from the center, providing a clear indication for the time to avoid any confusion. Retained are the visible barrel and micro rotor, though now supported by clean geometric bridges harkening to pocket watches of the past. The entire presentation has the goal of reducing details to the essential for a cohesive package.

The previous case design has been trimmed down to create the first 41-millimeter case for Armin Strom. The iconic lip at 6 o’clock, which can be traced back to Mr. Armin Strom himself, is still present, though in a much more streamlined form. Armin Strom has taken the opportunity to improve finishing on every component throughout the movement, creating a new standard for Armin Strom calibers.

The entire philosophy of development at Armin Strom is reorganizing to focus on updating the aesthetic design to signify a new chapter for the brand. The intention is to take every opportunity to rethink watchmaking theory, improve each new watch, and take Armin Strom’s level of finishing ever higher.

System 78 - A new entry to Armin Strom

"The Gravity Equal Force signals a new direction for the brand, launching the System 78 collection to replace the Single Barrel Collection. The collection is intended to be the entry point for Armin Strom, an haute horlogerie collection at a reasonable price point with impeccable finishing and constant invention. 

“It’s not self-evident that we can present our watchmaking values and hunger for innovation to a broader audience. It was a big challenge to offer this level of perfection for that price” says Serge Michel, Founder of the Manufacture.

The name displays what the brand hopes to create, a System of fine watchmaking available to all who desire it. Every piece will feature an innovation as well as showcasing the watchmaking philosophy of Serge Michel and Claude Greisler, co-founders of the modern Armin Strom, both born in the same year, 1978. Thus the System 78 collection is born."