The Art Of Elapsed Time: An In-Depth Look At The DB25VXS Monopusher Chronograph

It’s no exaggeration to say that chronographs are the foundation of De Bethune – the very first watch in De Bethune’s series production was the DB1, which was released in 2002 (along with DB2, 3, 4, and 5). DB1 used a version of a movement which had been originally developed by Denis Flageollet, F.P. Journe, and Vianney halter at a company the three watchmakers had founded, THA (Techniques Horlogères Appliquées) in the 1990s; that movement caliber 045MC, had been developed for the Cartier Monopoussoir CPCP ref. 2396B. The DB1 would be followed by the 2003 DB8 monopusher chronograph, which used a version of the 045MC modified to give it a single 45 minute counter, and then, in 2006, the DB21 Maxichrono, which is certainly one of the most ingenious and complex chronographs ever created – the Maxichrono, which has five hands, all on the same center axis. (As if that weren’t enough, in 2014, De Bethune launched a tourbillon version of the Maxichrono).

Then, in 2023, De Bethune announced another milestone: the DB Eight, ref. DB8RETIS1, which used a brand new chronograph movement. This watch uses the caliber DB3000, which is an oscillating pinion, column wheel controlled chronograph movement, with De Bethune’s patented flat balance spring and titanium and white gold balance. The latest chronograph from De Bethune, the DB25VXS, is essentially a smaller version of the DB Eight, but also using the DB3000, and following the design cues of its larger predecessor.

The aesthetics of the DB25VXS are rather more conservative than not, at least compared with the techno-futuristic feel of many of De Bethune’s other watches. The case, at 40.6mm x 9.15mm, is smaller than the DB Eight’s 42.4mm x 9.2mm case, but other than that, they’re physically identical; both are made of grade 5 titanium, and the watch feels quite light in the hand and on the wrist thanks to the construction (essentially, a titanium mid-body, with sapphire crystals front and back; most of the mass of the watch is actually in the movement). The lugs are the most distinctively De Bethune element of the case; they are openworked, with a small version of the ogival (arch) shaped lugs introduced in the very first De Bethune watches – miniaturized, but still present.

The dial is also from the same playbook, and it’s a little work of art in its own right, with guilloché applied at De Bethune (all the components, including the dial and hands, are made at De Bethune’s manufacture in L’Auberson, Switzerland). The dial itself is silver, with a radiating, scalloped guilloché pattern arranged in 12 sections, corresponding to the hour markers, which has a very finely engraved border on its circumference.

The sixty minute counter for the chronograph is located where you’d normally expect to see a subdial for the running seconds, and, indeed, it’s possible at first and even second glance to mistake this for a time-only watch. The sixty minute counter is sunken, with a central guilloché barleycorn pattern, and on close examination you can see how well the different textures and the placement of the borders of each area of the dial play off each other. The sixty minute counter is quite large, covering almost all of the available space between the edge of the dial and the posts for the hour, minute, and center chronograph hands. (Its frame is also in a stylized horseshoe shape, which reminds me of the case shape of the 2005 DBS – which at its launch, defined a new direction in design at De Bethune, which has been unfolding ever since).

You might think that the hands are blued steel, but they’re not; they’re actually blued titanium, which is something of a signature feature in De Bethune watches. The overall effect of the dial is quite serene – De Bethune’s watches can run the gamut from almost simplistic, to absolute horological maximalism but the dial of the DB25VXS is definitely on the minimalist end of the spectrum.

Caliber DB3000 is, from a design standpoint, composed almost entirely of mirror polished and chromium plated steel, and the movement bridges are quite unconventional in comparison to a standard chronograaph movement. There are nonetheless, some identifiable components which anchor the composition. At 3:00, you can see the balance under its balance bridge; the balance is in blued titanium with white gold rim weights and acts as the only splash of color on the movement side with the exception of a couple of the chronograph wheels. The mainspring barrel, which outputs about sixty hours of running time, is at 12:00 in the image below, and the very compact column wheel is directly adjacent to the crown, left at 9:00. The chronograph seconds wheel is in the center, under the same bridge as the wheel for the instantaneous jumping minutes, at 6:00.

Although the steel chronograph bridges are unusual and very visually striking, underneath them there is some quite traditional watchmaking. In particular, the steel for the chronograph levers and jumper springs is finished in a very traditional way, with straight grained upper surfaces and beveled edges.

The heart cams for reset to zero are located directly under the two bronze colored chronograph wheels, and you can see the tilting, or oscillating, pinion at about 4:00 from the chronograph center seconds hand. The silicon escape wheel is just to its right, and then there’s that blued titanium balance, which is designed in such a way that its weight is low but its moment of inertia is high (moment of inertia is just a way of measuring how resistant a rotating object is to being disturbed, which is a function of both the effective mass of the rotating object, and the radius of the mass from the center of rotation). You can also see De Bethune’s patented flat balance spring, which is essentially an affix on the outer terminal curve, whose purpose is to provide the same advantages as a Breguet overcoil but without the height (the advantage in question being the spring “breathing” more concentrically).

The tilting pinion system; image, TAG Heuer, via Revolution

The so-called oscillating, or tilting, pinion system is older than you might think, having been invented and patented by Edouard Heuer all the way back in 1887. It is, as they say, exactly what it says on the can: a pinion with sets of teeth at either end, which can tilt in and out of engagement with the center chronograph seconds wheel. In the image above, the fourth wheel h which turns once per minute, is geared to the lower pinion teeth at a’ and both the fourth wheel and pinion rotate continually. When the chronograph is switched on, the pinion tilts on its lower pivot, bringing the pinion teeth at a into contact with the chronograph seconds wheel b. The basic advantages to the system are that it’s easier to adjust and construct than a lateral or vertical clutch, and it also reduces the tendency of the chronograph seconds hand to jump when the user starts the chrono, as the pinion teeth are finer than those on the clutch wheel in a lateral clutch chronograph (for a detailed breakdown of the pros and cons of the tilting pinion system, see Cheryl Chia’s excellent analysis at Revolution).

As we’ve said, this is De Bethune in perhaps more of a minimalist mood, but the level of attention to detail is just what you’d expect, which is to say, thorough and painstaking. The DB25VXS uses fewer design elements, but all the defining features of a De Bethune watch are still there, both front and back, including the contrast of white metal (silver in the front, steel in the back) with blued titanium, and certainly, the architecture of the caliber DB3000 is very unusual by any standard, offering a highly idiosyncratic take on chronograph movement design, along with some very classic finishing in the steelwork.

And it’s not only a visual pleasure, it’s a tactile one as well; light and graceful on the wrist, with a silky feel to the operation of the chronograph that, among other things, handily disproves the idea that a tilting pinion design doesn’t offer the same refinement as a lateral clutch. It’s a combination of very contemporary watchmaking and watch design, with an underlying connection in its design to classic watchmaking that keeps it grounded in history.

The De Bethune DB25VXS Monopusher Chronograph: case, grade 5 titanium, 40.6mm x 9.15mm, with open “ogival” tipped lugs; dial, silver, hand-applied guilloché decoration, with sunken register for the chronograph minutes counter; water resistance, 30 meters. Movement, De Bethune caliber DB3000, monopusher chronograph, center chronograph seconds with instantaneous jumping 60 minute counter at 6:00; column wheel controlled, with tilting pinion; 60 hour power reserve, running at 28,800 vph in 31 jewels; chronograph bridges in chromium plated steel. The 1916 Company is proud to be an authorized retailer for De Bethune; see the DB25VXS here.