Like most debates in watchmaking, there is unlikely to be an end to it. We have no hope of settling anything, but you should know what you are getting into in the wonderful world of chronographs.

To begin with, collectors do have a clear preference – call it bias if you will – towards integrated calibres. There is no single reason for this, although the significant expense to develop a calibre from scratch certainly plays a part. While this does please a collector of means, it does not mean that everything developed this way is extraordinarily expensive, at least from the perspective of relative recommended retail prices. Economies of scale allow Rolex, Omega, Breitling and Tudor to offer integrated chronograph movements at quite attractive price points (availability notwithstanding). With regards to the Rolex Daytona in particular, we think that the price- to-value ratio here is one reason the model is so popular; it has consistently seen its so-called market value listed comfortably (or uncomfortably depending on your perspective) above its retail price. This is also the reason we opened this entire section with the Daytona, possibly the most valuable and desirable chronograph in the world, new and vintage.

It is also worth bearing in mind that integrated chronographs are just as likely to be of the column wheel variety or the cam-actuated kind. Look no further than the above-mentioned Valjoux 7750 for an example of an integrated chronograph calibre that uses a cam-lever system (another name for the simplified chronograph mechanism). This calibre is hardly an outlier, with the legendary Lemania 1873, also using a cam-lever system. This was the forerunner of the Omega Lemania movement that went to the moon, it should be noted.

What then of the modular movement? Well, it too depends entirely on who makes the calibre in question, and who makes the most noise about it. This year, Grand Seiko has the honour of delivering perhaps the most significant modular chronograph in recent memory. Yes, this is the aforementioned Tentagraph again, but one should keep this remarkable watch in mind as it may yet change minds in the collector community. It joins the likes of TAG Heuer and Breguet, with both historical and contemporary models. While the brand names are alphabetically close to each other, Hublot and Grand Seiko are unlikely to ever share the same space, except with regards to the modular chronograph, because of the in-house HUB 1242 movement introduced in 2009. In fact, this was the last time a modular chronograph piqued the interest of as many enthusiasts, although now that it has been upgraded to the HUB 1280 version, hardly anyone remarks on the modular construction anymore. Perhaps another apt comparison will be to the IWC Doppelchrono, which uses cams all the way and also adds the split seconds function via a module. Again, no one says anything about the modular nature here.

Overall, the most highly regarded contemporary chronograph movements are of the integrated variety though. This includes everything from the Zenith El Primero and the Rolex 4131 to the Patek Philippe calibre CH 29-535 PS. In fact, Zenith went all the way to develop a base movement from its El Primero, which today powers the Defy Skyline, for example. That one is an outlier though.

The principal difference between an integrated mechanical chronograph calibre and a modular one is in how the chronograph function is incorporated into the overall movement. That means, in short, how the chronograph components sit within the overall movement. In the integrated mechanical chronograph, the chronograph function is built directly into the base movement. Indeed, the watch movement was designed to be a chronograph, with such considerations as where the fourth wheel goes informing the architecture. This means that the chronograph components (such as the chronograph wheel, coupling clutch, and reset mechanism) are fully integrated with the regular timekeeping components of the movement.

In the modular system, a chronograph module containing all the chronograph parts is added on top of a base movement, much like a calendar module might be added to a base movement. Or even as a calendar module might be added to an integrated chronograph, as 7751 is to 7750. An important point here is to be clear in understanding what modular means and refers to. For example, in our Agenda story on chronographs, from whence this story began, we called the MT5813 calibre modular, which it is, but the chronograph is of the integrated variety. Typically, to recognise the chronograph module, the movement will place the chronograph gear train dial-side, allowing for less visual excitement via the caseback. This means that the caseback view will deceive the casual observer into thinking that fewer parts are involved than in the case of the integrated chronograph; this is not the case.

The chronograph pushers are likely to be along a different axis to the crown, given that the pushers need to interact with the chronograph module. The crown, of course, will be aligned with the main movement. This misalignment between pushers and crown can be a deal-breaker, because once you see it, it will annoy you to no end. We can happily report the alignment issue is not always there, as the Tentagraph demonstrates. On the other hand, modular chronographs to tend to be thicker than integrated ones, and the expert advice is that this is very noticeable. Again though, if you know anything about calibre 7750, you know it is not a paragon of thin chic, and neither is the Lemania 5100.

This article was first seen on WOW’s Autumn #70 Issue. 

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