Collectors Note: The “Microtor only” dials

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Collectors Note: The “Microtor only” dials

The development of the microtor movement was a true technological marvel for the watch world in the 1950’s. This new design incorporated the automatic winding rotor into the movement, instead of situating it above the movement (as it was with the common central winding rotors of the time), and therefore allowed the thickness of the watch to decrease significantly. It allowed Universal Geneve to produce the thinnest automatic winding wristwatches, from the late 1950s through the 1960s.

The first UG patents for the Microtor design (see here) date from 27th of May 1955, which at the time gave way to a legal fight over the use of the word “Microtor” with Buren watch co. – who had independently developed their own Microtor winding system in parallel.

The UG microtor calibers were introduced to the watch world within the Polerouter models, and continued in various iterations through the 1970s. Universal didn’t miss an opportunity to show off this new technological feat, and the word “Microtor” would appear on the dials of watches that incorporated these movements, for many years.

We can start to dive a little deeper by stating the obvious, that not all Polerouter dials are identical. There are seemingly countless numbers of different colours and finishes throughout the range. Even individual sub-references saw minor changes throughout their production, which can be seen by slight differences with crosshairs, text colours, and even changes on the wording itself. These are usually fairly straightforward to differentiate, and they can be separated into small serial batches that each have identical characteristics. One of these batches is what is referred to as the “Microtor only” dials.

What is a “Microtor only” dial?

Most Polerouter dials display different combinations of “Automatic” and “Microtor” in the lower half of the dial. Simply put, the “Microtor only” dials only have the text Microtor printed in this section, with no reference to Automatic anywhere. The difference can be seen below, with a “Microtor only” dial on the left, and a more common “Automatic Microtor” dial on the right. The existence of these dials is also supported by early Universal Geneve advertising (below).

Which references had Microtor Only dials?

Only three Polerouter references had “Microtor only” dials, and understandably these are the earliest references produced with Microtor movements: the 20360; the 20363; and the 10357. Not all sub-references have been found with “Microtor only” dials, but some of these examples are shown below.

Misidentification of “Microtor Only” dials

Many Polerouter dials were subjected to a multi-stage printing process, for examples where dial text was printed in a different colour. As a result of this, some dials often display uneven fading or wear of parts of the dial text, and can result in misidentification of a “Microtor only” dial. This is the case in some Polerouter references, and is often seen on black dial references such as 20360-1. As with the example below, the “Automatic” text has faded heavily (below, left), in this case it looks to be something on the surface of the text itself. On first glance, it appears to be a “Microtor only” dial, however, after some careful restorative surface cleaning, one can see it is in fact an “Automatic Microtor” dial (below, right), as one would expect with a later serial.

“Microtor only” calibers

The “Microtor only” dials were produced for a very short time, and only for the earliest references. For this reason, all “Microtor only” movements were 215 calibers. The earliest 215 calibers had some distinct markings on them, that correspond with these early dials. This includes the design and look of the balance cock (below left vs right), where a further adjustment was added later.

The earliest movement plates also had “Patented Rights Pending” around the edge of the rotor, as they were paying a licensing fee to Buren until their 1955 patent application was formally granted in 1958. After 1958, this text was replaced with the official Swiss patent number 329805 (below, right). The changeover from one to the other was not timed exactly with the change from “Microtor only” to “Automatic Microtor” dials, so one can say that all “Microtor only” dials should have the movement type on the left, as well as some of the earlier “Automatic Microtor” dials.

Production and Rarity

As mentioned earlier in the article, “Microtor only” dials are believed to have appeared on just three Polerouter references, the 20360; the 20363; and the 10357. From serial numbers collected in the database so far, they group well, with the order of production being first 20360, followed by 10357, then 20363, and all within the earliest of the 183-184xxxx serial ranges (though varying by sub-reference). The database also alludes to the production number being uneven between sub-references, and somewhere between around 200-500 for each.

However, these “Microtor only” dials represent a small fraction of the reference productions overall (i.e. only a few percent), so any estimation beyond this is difficult at the moment. In that respect, this also means that their comparative rarity is significant, and time will tell whether “Microtor only” examples become more collectible and sought after than the later, and more numerous, “Automatic Microtor” examples.

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