Armin Strom One Week Titanium Skeleton: 7-day power reserve in a fully openworked, lightweight design

0 0 Thursday, 10 April 2025 Edit this post

At Watches and Wonders Geneva 2025, Armin Strom unveiled the One Week Titanium Skeleton, a new addition to its One Week line, originally launched in 2023 and previously reviewed by us.

This release rounds off a dynamic week of novelties from the independent watchmaker based in Biel/Bienne, following the Orbit Purple and the Dual Time GMT Resonance Manufacture Edition Black, both of which we covered in recent days.

With the new Armin Strom One Week Titanium Skeleton, the heart of the watch, its movement, is revealed through a meticulous skeletonisation of its main components.

A pioneer in skeletonisation and a master watchmaker, the passion of Mr. Armin Strom for exposing the beauty of fine mechanics continues to inspire the current leaders of the brand, Serge Michel and Claude Greisler, focused on pushing the boundaries of horology while respecting tradition.

The new model comes in a 41 mm x 10.6 mm case crafted from lightweight Grade 5 titanium featuring a fully integrated bracelet in the same material. The contemporary and dynamic design of the One Week Skeleton is well highlighted by alternating satin-brushed and polished surfaces.

Water resistance is guaranteed up to a pressure of 10 ATM (approximately 100 metres / 330 feet), thanks in part to a screwed-down crown, well protected by two guards that enhance the sporty look.

The 2023 One Week was already openworked by design, but this version takes it a step further, removing even more material to accentuate the movement's intricate complexity.

The mainplate and the barrels are also skeletonized, enhancing aesthetics.

The two mainspring barrels work in series to provide consistent levels of energy to the gear train and are held by two sculpted finger-style bridges. The process of manual winding creates a captivating spectacle as the two barrels wind up in opposing directions.

Between 10 and 11 o'clock, the power reserve is indicated by a cone system inspired by pocket watches and consisting of a mirror-polished cone, which is driven by a conical gear on the opposite side of the dial.

The faceted hour and minute hands are positioned in the centre of the dial, which is rather uncommon for Armin Strom watches, usually featuring offset hour and minute hands, either on a subsidiary dial as small hands or slightly off from the centre as large hands.

In this model, a sub-dial is still present at 9 o'clock, serving as a small seconds display. Also skeletonised, it reveals the escapement wheel, adding visual depth and mechanical dynamism.

To maintain optimal legibility, the movement is surrounded by a chapter ring set with baton indices.

The hands and the hour markers are filled with Super-LumiNova, emitting a green glow in darker environments.

The transparent sapphire crystal case back displays the Manufacture Calibre ARM21-S (where S stands for Skeleton). This movement demonstrates Armin Strom's dedication to Haute Horlogerie showcasing an outstanding level of craftsmanship, both in terms of skeletonisation and finishes.

These include straight and circular grained surfaces, polished and chamfered bevels, and polished screws and sinks.

Held in place by a finger-style bridge, the balance wheel operates at a frequency of 3.5 Hz (25,200 vibrations per hour). With a 7-day power reserve, which gives this model its name, this watch keeps time accurate for an entire week without needing winding.