On Spec: The YEMA Wristmaster Traveller Micro-Rotor and the CMM.20

A few weeks ago I was listening to an episode of The Grey NATO, where hosts James Stacey and Jason Heaton were interviewing Asher Rapkin of Collective Horology. They were discussing the California-based collective’s latest collaboration with Swiss watchmaker Armin Strom–The Gravity Equal Force P.03. We’re talking haute horologie well above my pay grade, here. But it was a fascinating interview, particularly their discussion of the P.03 and its Calibre ASB19 which lies at the heart of Armin Strom’s System 78 collection.

In a layman’s nutshell, the ASB19 endeavours to deliver consistent energy from the barrel to the balance wheels, offsetting what is known as “poor isochronism”–essentially an imbalance that occurs naturally as the torque of a fully wound watch winds down. As a watch winds down, this imbalance increases and the watch becomes slightly less accurate. The solution is to use only the maximum range of torque to power the movement. To do this, the ASB19 uses a stop-seconds mechanism that is only 35.5mm in diameter, and is wound by a “micro-rotor.”

If you’re lost now, just know this: The Gravity Equal Force P.03 retails for $25 000.

Armin Strom is a fully vertically integrated watchmaker. They are at the cutting edge of horology. Simply put, they make cool stuff. Cool, expensive stuff.

So where does YEMA fit into this? Well, they also make cool stuff. Cool stuff I can afford. Oh, and remember that “micro-rotor” thingy mentioned above. That’s important.

YEMA Wristmaster Traveller Micro-Rotor CMM.20 Watch Review
Wristmaster Traveller Micro-Rotor with CMM2.0

YEMA and French Watchmaking

A watchmaker does not become a vertically integrated Manufacture overnight. Since 1948, YEMA has been a key player in the world of French watchmaking–a history that, not unlike Switzerland’s, reaches back hundreds of years. However, the last two years have been a period of transition and a pivot in vision for the brand.

You may recall that the company made headlines when it injected €3 million into research and development for the first generation of its inhouse MBP1000. They then harnessed the power of crowdfunding to refine that design into the YEMA2000 and 3000 iterations. But that was only the beginning. The last two years have been characterized by sizeable investments. The purpose of which is to increase the insourcing of its production through the upgrading and enhancing its manufacturing capacity. All the while, of course, the end goal is to develop and produce a future range of truly French Manufacture calibers.

YEMA Wristmaster Traveller Micro-Rotor CMM.20 Watch Review
Integrated Bracelet Sports Watch with Calibre Morteau Manufacture 2.0

For this next chapter to unfold, YEMA will also require local partners who can meet the same high levels of responsible production. No doubt this will mean further integration in what the brand is calling the “The French-Swiss Jura Arc.” From its conveniently located Morteau workshops, YEMA should be able to capitalize on the expertise available its French-Swiss relationships–all located within a radius of 72 km.

YEMA’s greatest investments, however, have come in people. Jean-Paul Boillot, for example, is YEMA’s Watchmaking Master. He hails from four generations of Morteau watchmaking, and has, himself, been working in the industry some forty years. It was Boillot who managed the development of brand’s first inhouse caliber. He is joined by Morteau’s Lycée Edgar Faure graduate–Nicolas Bailly–who spent five years developing manufacturing processes for Cartier’s automatic calibers; Olivier Mory, formerly of Audemars Piguet, Sellita, and the Richemont Group; as well as Patrick Augereau who has worked with Omega, and Audemars Piguet, where he developed their oiless escapement.

YEMA Wristmaster Traveller Micro-Rotor CMM.20 Watch Review
Easy wearing

The CMM.20 and the Wristmaster Traveller Micro-Rotor

The next step on YEMA’s journey to becoming a vertically integrated Manufacture has been baptized the CMM2.0–Caliber Manufacture Morteau 20. And it’s a micro-rotor. I told you this would be important. But judging from the outpouring of support on this month’s Kickstarter campaign many of you already knew that.

YEMA Wristmaster Traveller Micro-Rotor CMM.20 Watch Review
From design to execution

The Limited Edition Wristmaster Traveller Micro-Rotor will be the first to house the movement, and at the time of writing (and with eight days left in the campaign), customers have already pledged €2 116 000, eclipsing the initial goal of €50 000.

This latest iteration of the Wristmaster Traveller is a luxury sports watch with an integrated bracelet. It offers 100m of water resistance and a glorious view of the new CMM.20 through its sapphire exhibition caseback.

YEMA Wristmaster Traveller Micro-Rotor CMM.20 Watch Review
A ripple through the watch world

The movement is 80% French and 20% Swiss. With the exception of the regulating organ, all components were manufactured in the brand’s Morteau workshops. The caliber purportedly offers an accuracy close to COSC standards at -3/+7seconds/day. The balance wheel is fashioned from Glucydur, which is a non-magnetic metal alloy and its oscillating winding mass is forged from a high-density tungsten alloy. It also offers a respectable 70-hour power reserve.

But it’s the “micro” which is the key here. The new, ultra-thin caliber measures a mere 3.70 mm, making it 26% thinner than the ubiquitous ETA 2824.

YEMA Wristmaster Traveller Micro-Rotor CMM.20 Watch Review
1980s Sous-Marine inspired bezel

This allows the new Wristmaster Traveller–which is already a tidily-sized 39mm in diameter and 43.5mm lug to lug–to come in at an incredibly thin 9.2mm (down from its original 12mm).

The CMM.20 is a 4Hz movement, oscillating at 28 800bph and has 33 jewels–not to mention 190 micro-components. It comes adjusted to four positions.

YEMA Wristmaster Traveller Micro-Rotor CMM.20 Watch Review
Atomic Layer Disposition oxidized coating

In many ways, the Wristmaster platform is the perfect vehicle with which to introduce the CMM.20. Instead of the classic guilloche decoration, the CMM.20 has a much more minimalist appeal, which suits the simple elegance of the Wristmaster. The uniformity of the movement finish is also reflected in the homogeneous appearance of an integrated sports watch.

The movement has undergone satin brushing and polished micro-blasting and also comes in three colours to match each of the watch dial references. Positive Coating, another of YEMA’s Swiss connections, has treated the mainplate and bridges with ALD (Atomic Layer Disposition) to achieve the desired colour and finish–a process often used to treat medical instruments, whereby successive nano-layers of oxide coatings are applied to achieve a hermetic seal.

The Wristmaster, as such, is truly a case where the underside of the timepiece is just as luxurious–and pleasing to the eye–as the dial.

YEMA Wristmaster Traveller Micro-Rotor CMM.20 Watch Review
Only 9.2mm thick

Nonetheless, if you are not a movement junkie, the rest of the watch will not disappoint. The dial texturing looks like the ripple effect of a stone tossed into a pond. Perhaps, metaphorically, that is YEMA’s expression of the impact the brand is hoping for with this watch and its new caliber. The markers are applied and lumed, and the watch retains its eccentric “Wristmaster” script above the six position. Otherwise, the dial is clean.

The fixed bezel is a revival of sorts, harkening back to a Sous-Marine model from the 80s, but moves away from the diver aesthetic toward a more broadly appealing sports design. It looks like the sapphire crystal sits just slightly proud, and will no doubt catch light nicely.

YEMA Wristmaster Traveller Micro-Rotor CMM.20 Watch Review
Slim, tapered bracelet with butterfly clasp

Next to its movement, the Wristmaster’s triumph might actually be its bracelet. The seamless flow of vertical brushing and polished chamfers tapers from 24mm at the case, to a much slimmer 20mm at the well-executed butterfly clasp. At only 3mm thick, it must also be quite comfortable on wrist.

As a nod to its year of inception, YEMA have promised 1948 individually numbered pieces. And, wait for it, you won’t be paying $25 000 for this micro-rotor. Supporters who act during the Kickstarter campaign will be rewarded handsomely with a price tag of €1499. Those who hesitate will be picking up a heftier retail tab of €2998.

YEMA Wristmaster Traveller Micro-Rotor CMM.20 Watch Review
The Wristmaster Traveller Micro-Rotor

About the author

Brent Robillard is a writer, educator, craftsman, and watch enthusiast. He is the author of four novels. You can follow him on Instagram.

On Spec articles refer to upcoming projects and rely upon available information on Kickstarter, the brand website, and promotional materials provided by the watchmaker. An On Spec article does not preclude a future full-length review in our Off The Cuff section. If you would like your project to feature in On Spec, please contact us here.

Please understand that using any links to products on this site might result in us making money.

3 thoughts on “On Spec: The YEMA Wristmaster Traveller Micro-Rotor and the CMM.20

  1. Just a great Company making marvelous progression forward in design and development with business sense. All of that said, Yema will be around for many year more. I personally got word of this and jumped on board immediately… I truly believe this could be the piece that turns the corner for Yema and puts them into the luxury market as well‼️

    Liked by 1 person

  2. Pingback: On Spec: YEMA Navygraf Chrono & Chrono UTC – Calibre321

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