Montblanc 1858 Unveiled Secret Minerva Monopusher Chronographs: An In-Depth Look

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Amanico's insightful review of the Montblanc 1858 Unveiled Secret Minerva Monopusher Chronographs from Watches and Wonders 2022 offers a deep dive into a truly innovative horological concept. He meticulously explains how Montblanc ingeniously re-engineered the Caliber 16.29 to display its stunning movement on the dial side, a feat that required significant modification and additional components. This article explores the technical brilliance and aesthetic appeal of this unique approach to showcasing a chronograph movement.

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There are more and more fans of Montblanc Minerva Chronographs, with years passing, and rightly so. Basically, you have two gorgeous manual winding movements, the Cal 13.21 and the much bigger Cal 16.29 whose level of finishings is among the best, IF NOT the best.

If you are a fan of fine movements, you might have been tempted to wear your beloved watch upside down, I mean with the back side instead of the front side,which is not very practical nor comfortable, except if you have a skeleton watch or a watch like the Jaeger Lecoultre Reverso.

With the 1858 Unveiled Secret Minerva Monopusher Chronograph, you can read the time AND admire your chronograph movement.

The knack? Take a Cal 16.29 and install it upside down, the back of the movement on the dial side.

The problem? The hands. Montlblanc had to adapt the movement, by adding 21 extra components, in order to install them on the backside of the movement, which is now upside down. So, from 252 parts, you now have 273 parts for this movement whose reference has changed, too, which is the Cal 16.26 instead of the Cal 16.29.

My passionate and young interlocutor at Montblanc told me that they changed the reference of this movement because it is a new movement AND because when you turn a 9 upside down, you have a 6. Great idea, in my opinion.

Some other different details have to be mentioned.

- While the 1858 housing a Cal 16.29 used a 44 mm case, here we have a 43 mm case, with some deliciously beveled lugs. Here you have two versions, one in lime gold, which has a hue between green and yellow, and the other in steel, with a white gold bezel.

The generous bevels on the lugs:

The lime gold case is not a first, as there was an exclusive 1858 Split Seconds which used this specific color, issued in 2021.

- Both versions have a fluted bezel, which is another novelty for a 1858 " Cal 16.29 ".

- Last but not least, this is the only 1858 housing a Minerva movement having a... Solid Case Back! This option makes sense, since the show has been replaced on the dial side.

Moreover, the engraving is superb. And it also enhances the sculptural beauty of this movement. I am not sure it would be as beautiful if it had been a skeleton.

To be complete, The steel version is limited to 58 pieces, while the lime gold is only 18 pieces.

I could see both in real life, I was allowed to take photos of the steel only, because the Secret didn't have to be unveiled on the Lime gold, yet and I found both very appealing. I am not a colored gold fan, so my preference goes for the steel, naturally, but I cannot deny a strong charm to the Lime Gold. The only thing I am not totally mad about is the fluted bezel. A smooth one would have made my day.

Looking forward to reading your comments and thoughts,

Best.

Nicolas

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 concept of an 'unveiled secret' movement, where the caliber is visible from the dial side, is highly appealing, but some collectors may find that the practical enjoyment of an open dial doesn't outweigh the classic aesthetic of a traditional dial, especially if they already own similar high-end chronographs.
The addition of 21 extra components to adapt the Caliber 16.29 into the Caliber 16.26 for the 'unveiled secret' configuration raises questions about potential increases in watch thickness.
The 'unveiled secret' concept, while innovative for Montblanc, has been explored by other independent watchmakers, such as Voutilainen, suggesting a broader trend in high horology to showcase movement architecture.
The green dial version of the Montblanc Minerva chronographs, particularly the smaller size, remains a favorite among collectors for its color combination and more wearable dimensions, even with the introduction of new 'unveiled secret' models.
The 'open dial' design of the 1858 Unveiled Secret Minerva Monopusher Chronograph elevates the watch to another level, highlighting Montblanc's exceptional craftsmanship.
The Montblanc LE18 lime gold rattrapante is described as 'spectacular in the metal,' indicating that Montblanc continues to impress collectors with its high-end, limited-edition offerings beyond the 'unveiled secret' models.

The Discussion

TeutonicCarFan

May 10, 2022

Was waiting for this write up!

I am a big fan. I love the idea of seeing the movement in action. Actually after seeing your photos and a weh koh video I went and reserved a steel one. I was very excited to be able to see the movement in action. Very appealing. However, after reflecting for a day or two I thought as much as I like this concept and seeing the movement in action from the dial side, I realized I still would grab my enamel 16.29 to wear. In the end I cancelled. Which is okay. I need to decide more often just becau

amanico

May 10, 2022

Among the Montblanc novelties from this year, I would grab the Red Arrow, and I will explain why in my review to come. ;)

Chronometer (aka yacomino)

May 10, 2022

I am torn the same way here as I am extremely excited about this watch but fear of a faded passion for the open work design with time…it is indeed hard to assess without seeing it in the flesh and with proper wristshot…

amanico

May 10, 2022

Try to see it in real life, you will know.

Chronometer (aka yacomino)

May 10, 2022

I might be able to after all as my AD is supposed to get one in September…crossing my fingers!

dedestexhes

May 10, 2022

I’m with you on the bezel. And honestly, I like the classic approach more, just a plain beautiful movement at the back.