Just released by Armin Strom is the new Gravity Equal Force P.03 done in collaboration with California-based Collective Horology. Geared towards watch enthusiasts with a real eye for horological innovation, the Armin Strom Gravity Equal Force is one of those “hidden gems” that collectors have been raving about for the last couple of years. I’ll get into what exactly makes this watch special, but what’s new about this specific piece comes with the collaboration. Collective Horology was founded by Asher Rapkin and Gabe Reilly in 2018 as a private member collectors group that has done projects with mainstream brands like IWC and Zenith as part of their “Collective Series” and independent names like J.N. Shapiro and Urwerk for their “Portfolio Series.” The Gravity Equal Force P.03 joins the latter group and, as the P.03 designation indicates, is the third in the Portfolio Series.
This isn’t a mere “colorway collaboration” as there are some significant changes and flourishes made to the base watch. Notably, this is the first Armin Strom Gravity Equal Force watch to be done in a titanium case. Additionally there are milled-out pockets on the two top and bottom dial-side bridges while the shorter center bridge has a step. Below you can see a photo of the standard issue steel model that I photographed some time back side-by-side with the P.03 for comparison.
The case of the Gravity Equal Force measures 41mm wide and 12.65mm thick with 30m of water resistance. For the P.03, the offset dial is done in a matte khaki fumé with lumed coating on the hands and numerals as well as mirror-polished indices. You’ll also notice the “tech-style” guilloché pattern done on the movement plate in the background. The color scheme is really quite attractive, especially coupled with the khaki rubber/leather strap that is excellently finished and very comfortable.
The openworked Manufacture ASB19 automatic movement features a micro-rotor which you can see on the dial side at 1 o’clock and equal force barrel beneath it at 6 o’clock. If you’re unaware of the impressive developments Armin Strom has made to core watchmaking as part of their “System 78” collection, here is a brief primer on the salient mechanism. The Gravity Equal Force mechanism is a rather ingenious way of negating the adverse effects of poor isochronism on accuracy. The extremes of inconsistency in torque come when a movement is fully wound (high torque) and when it’s nearly unwound (low torque). This mechanism doesn’t use the first few turns of the barrel at all and, in fact, limits the mainspring barrel to nine full turns out of a possible twelve-and-a-half. By sacrificing a longer power reserve, Armin Strom delivers a 72-hours that are remarkably accurate. As this is an automatic movement the issue of overwinding is addressed by the novel “stop-work declutch” which is used on a self-winding caliber for the first time ever here.
On the case back side you can see the regulating system with four screws and the large plate adorned with hand finishes and elaborative text. The ASB19 is comprised of 202 parts and operates at a quirky 25,200 vph. While it would be fascinating to see data on how the innovative mechanisms at play here benefit accuracy, that information is actually not made available by Armin Strom.
Since its initial release a couple of years back, the Armin Strom Gravity Equal Force has presented a refreshingly novel and impressive display of watchmaking especially when considering this is a time-only watch, and an automatic one at that. Who else but a spirited independent brand like Armin Strom would invest and dedicate so much to a product with such a niche appeal? It’s why I love to see the emergence of groups like Collective Horology which have done so much to introduce a new generation of collectors to pieces like this one.
The Armin Strom Gravity Equal Force P.03 with Collective Horology is limited to 30 pieces and is priced at $25,000. As with all their watches, it will be available to existing and new members of Collective Horology which you can learn about at collectivehorology.com and to learn more about Armin Strom please visit arminstrom.com.