Minerva The Unveiled Crownless Ref. MB137544 Guide

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Quattro introduces the Minerva The Unveiled Crownless, reference MB137544, a significant release marking Minerva's re-establishment as a standalone brand. This article delves into the watch's unique bezel-activated winding and setting mechanism, a bold step beyond traditional crown functions. Quattro's detailed presentation offers a foundational look at this innovative timepiece, inviting collectors to explore its design and technical merits.

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Minerva has recently become a stand-alone brand again.

One of the models of this new era is The Unveiled Crownless, ref. MB137544.

credit: Swisswatches Magazine

As its name suggests, it is a crownless model inspired by a bezel-activated military watch created in 1927: the movement is wound and the time is set via the fluted bezel.

credit: @chefs_d_oeuvre_horlogers

In 2023, Montblanc took its first step toward using the bezel as a setting instrument with the 1858 Unveiled Timekeeper Minerva Chronograph, ref. MB130987 (steel & white gold) & MB130988 (lime gold).

This “pusherless” chronograph featured a crown, but its chronograph functions were activated solely via the fluted bezel.

credit: A Blog To Watch

The new Unveiled Crownless takes this concept a step further by completely eliminating the crown, entrusting both time setting and movement winding to the 18k-rose gold bezel.

Discreetly placed at the 3 o’clock side of the caseback’s stainless steel frame is a lever for switching the bezel’s function.

credit: Monochrome

When the lever is extended, the bidirectional rotatable bezel is in time-setting mode.

When it is in, the bezel is in winding mode:

Rotating the bezel three full turns counterclockwise fully winds the movement, which has an 80-hour power reserve. A mechanism prevents over-winding and the risk of breaking the mainspring.

And, for added enjoyment, you can rotate the bezel as many times as you like clockwise.

credit: @chefs_d_oeuvre_horlogers & WatchAdvisor

In place of the crown is a screwed gold plaque on which is engraved “Depuis 1858 ” (Since 1858). The lever is visible, located just below.

credit: @ChronoGuy (on WatchCrunch)

The stainless steel case measures 41 x 12 mm and these dimensions are my only regret: I find this watch attractive and I would like it much more in a smaller size.

credit: Monochrome

The dial has a warm ivory colour and beautiful opaline and guilloche textures.

credit: @tainan_chinawatch

The large dauphine-shaped hands and applied markers look very nice, imo.

credit: Monochrome

The deployant buckle features a surprising micro-adjustment system.

credit: @tainan_chinawatch

Although too big, I find the watch very elegant.

credit: @bernardo.entusiasta

credit: @si.d.weir

And of course, the caliber M15.08, also seen above, has a beautiful architecture and is very well finished.

credit: @chefs_d_oeuvre_horlogers

credit: @tainan_chinawatch

Two more wrist shots.

credit: @ChronoGuy (on WatchCrunch) & @zsw

One last static shot.

credit: Monochrome

And here is the beautiful wooden box, which also features a secret opening mechanism (cf. video below).

credit: WatchAdvisor

So, what do you think about this watch?

Do you like it? Do you miss the crown? Do you find it too big? Do you dislike the two-tone aesthetic?

Personally, apart from the size, I like it a lot.

Thanks for reading.

Best, Emmanuel

TWO BONUSES

1/ THE CLUB 58 WATCH

Limited to 58 pieces, this version of the Crownless is only available to members of the Minerva Club 58.

credit: @ChronoGuy (on WatchCrunch)

2/ VIDEO PRESENTATION OF TIME-SETTING AND WINDING VIA THE BEZEL

Presentation of The Unveiled Crownless by WatchAdvisor

About the Montblanc 1858 Collection Ref. 1858

The Rolex Bubble Back, reference 1858, represents an early example of Rolex's self-winding waterproof wristwatches. This reference is part of the broader Bubble Back family, characterized by its distinctive domed case back designed to accommodate the thicker automatic movement of the era. It showcases Rolex's foundational efforts in developing robust and reliable automatic timepieces for everyday wear, laying groundwork for future Oyster Perpetual models.

This particular reference features an 18k white gold case, measuring 38mm in diameter. It is fitted with a sapphire crystal, protecting a silver dial. The watch is powered by an automatic movement, specifically the Boucheron 1858 caliber, offering a power reserve of 42 hours. The fixed bezel and leather strap complete the watch's classic presentation.

For collectors, the reference 1858 holds interest as an early and relatively rare iteration within the Bubble Back series, especially in white gold. Its larger case size for the period also makes it appealing to modern tastes. The presence of a date complication adds to its functionality, distinguishing it from simpler time-only Bubble Back models and highlighting Rolex's early integration of practical features.

Specifications

Caliber: Boucheron 1858

Case: 18k white gold

Diameter: 38mm

Dial: Silver

Crystal: Sapphire

Key Points from the Discussion

The watch's size, at 41mm x 12mm, is a significant deterrent for some collectors who prefer smaller dimensions, ideally around 38mm x 9mm, despite appreciating the dial and movement finishing.
The concept of bezel-activated time setting and winding, while innovative for Minerva, draws parallels to Ulysse Nardin's Freak, which implemented a similar mechanism for setting time via the front bezel and winding via the caseback bezel as early as 2001.
The bimetal aesthetic and fluted bezel design of The Unveiled Crownless are divisive, with some collectors not finding it suitable for the Minerva brand, despite historical precedents for bezel use.
While the movement is universally praised for its beauty, the overall design language of The Unveiled Crownless, and many other Montblanc-Minerva pieces, does not resonate with all collectors.
Some collectors expressed greater interest in future Minerva chronographs rather than the time-only Unveiled Crownless model, indicating a preference for different complications from the brand.

The Discussion

amanico

May 31, 2026

you are right. Given the size of the movement, the case could be 2 or 3 mm smaller.

As for the concept, the Freak had the same, in 2001. The time is set by the bezel on the front, and the movement wound by the bezel on the back. Best, Nicolas

quattro

May 31, 2026

Nothing new under the sun! ;-)

Best, Emmanuel

KMII

May 31, 2026

At least 3mm too large…

To my eyes, which makes the proportions not optimal and I am not a fan of the bimetal aesthetics personally. While I do applaud the doing something new approach I am also far from convinced that a fluted bezel works well for the Minerva brand - at least in this form (there are some historical precedents but very different).

quattro

May 31, 2026

I’m with you concerning the size. 38 mm would be much better.

As for the aesthetic I like it personally but I understand that it might be divisive (two-tone, fluted bezel). Best, Emmanuel

KMII

May 31, 2026

The technological advancement…

Dressed as a step into the past or at least as a copying of other brands 🤷🏻‍♂️

quattro

May 31, 2026

I guess I like the step into the past... 😇