As you all may know by now, we at Goldammer are big fans of IWC's Caliber 89. Yet, as much examples as we have handled so far, a 'Zwyro' Cal. 89 hadn't come through our hands. We didn't even know it existed before a collector approached us with photos of a Cal. 89 that was unlike any you may have seen before
January 08, 2025
Wolf in Sheep's Clothing - The IWC Cal. 89 'Zwyro'
Marcus Siems @siemswatches
Collector, Author, Data Analyst
Imagine the most standard 1970s watch... It'll probably be a round case, silver dial, three-hander, stick markers. Nothing fancy but versatile. Something like an IWC ref. 810:
A classic evergreen - an IWC ref. 810AD (automatic with date) in gold. A great and versatile watch but nothing you'd expect to knock your socks off... Photo Courtesy of Hodinkee.
A reliable piece, a classic that can blend in with almost every style but nothing you'd expect to knock your socks off... Not at first sight. But what is when I'll tell you that there are about three dozen 810s out there that'll kick you in the nuts, breathless you'd wonder what else you may have missed during all the years of collecting. An inconspicuous case filled with wonder.
As you all may know by now, we at Goldammer are big fans of IWC's Caliber 89 ([guide], [cases]). Yet, as much examples as we have handled so far, a 'Zwyro' Cal. 89 hadn't come through our hands. We didn't even know it existed before a collector approached us with photos of a Cal. 89 that was unlike any you may have seen before:
The 'Zwyro' Cal. 89 inside a 'basic' IWC ref. 810... Have you maybe overseen one before? Photos Courtesy of collector Dongyi (@Dongyi212) & James (@slowjms).
In a lack of better words: Wow! The 'Zwyro' is a fully engraved and gold-plated version of the Caliber 89, which, if you remember, was originally designed to withstand the mechanic-threatening conditions on the battlefield. How on earth came this to be?
1) The Interesting Story of Mr. Robert Zwyssig
Robert Zwyssig is a former member of the board and Technical Director at IWC in Schaffhausen (14 years between 1964-76; [source], [source]). He founded his own company - Zwyro AG - as servicing center for IWC (operating until 2004) apparently while he was still employed at IWC.
Mr. Zwyssig then decided to step up his game. His aspirations were to no longer lead a 'mere' servicing center and bought between 34-36 Cal. 89 in 1969. With these movements he made a small run of artisanally finished movements, signing them 'ZZ'. Rumor has it the actual engravings may have been done either by his daughter or nephew ([source]) before the bridges and components were gilted. These movements were ultimately assembled and encased in 1975 as part of the reference 810.
Comparing the 'Zwyro' (left) with the 'standard' (right) Caliber 89 from IWC. Photos Courtesy of Dongyi (@Dongyi212), James (@slowjms) & Goldammer Archives.
2) The Whereabouts
Where and how the watches were later sold is unknown. During my research I came across five examples with serials in close proximity:
#1 Movement 1,932,219 - Case 1,978,733
#2 Movement ??? - Case 1,978,732
#3 Movement 1,932,716 - Case 1,978,763
#4 Movement 1,932,747 - Case ???
#5 Movement 1,935,033 - Case 2,004,407
Three to four of them appear to be situated in Asia at the moment, namely Japan and China. However, apart from the message I received a couple weeks back showing me the particular example it seems that no one has spoken (or rather written) about these pieces in over 15 years*! The only resources you can find right now are very very old forum posts.
Close-Up of the 'Zwyro' Cal. 89 - How about the quality of the engraving? Photos Courtesy of Dongyi (@Dongyi212) & James (@slowjms).
3) So What the ...?
But what do we have in front of us now**? As I mentioned earlier the Caliber 89 was originally designed and envisioned as the sturdiest of the sturdy three-handers. It was famously used for the military-spec IWC Mark XI. Engraving and gold-plating such a movement seems thus as out of place as getting a perm for a pool-party!
The 'original purpose' of the caliber 89 - a military-issued Mark XI. Photo Courtesy of Bulang & Sons.
These are odd pieces you'd rarely hear about and even rarer will see in the metal... But these are also not the first 'odd' or rather high-end Caliber 89 pieces in existence. Made by 'Isomura' during the 1960s we can also find a couple of platinum cased dress watches for the Japanese market:
A platinum IWC Cal. 89 (case made locally by Isomura) for the Japanese market from the 1960s. Photo Courtesy of OldWatchJason.
But coming back to the 'Zwyro' examples. You can actually find for example seasoned collector Michael Friedman going on the record (in 2010) saying the engraving itself appears rather 'heavy-handed' ([source]). And that's probably fair to some degree. The finishing might not be on par to what we see on the market today by virtuous manufacturers like Vacheron Constantin, Audemars Piguet or Patek Philippe. But let's put the 'Zwyro' executions into the right perspective here:
First, IWC/Zwyssig very likely had a different clientele (aka price point) in mind than the holy trinity examples. Second, given the time - remember Zwyssig bought the Cals. 89 in 1969 - these pieces were actually ahead of the curve. Audemars Piguet started 'skeletonizing' and engraving movements in the late 1960s (for example ref. 5293 in 1968). Vacheron Constantin started producing their ref. 33014 skeleton during the 1970s and Patek Philippe introduced the first skeleton ref. 3880 in the late 1970s.
Three examples of vintage skeletonized watches from the 1960s and 70s from the 'Holy Trinity'. Photos Courtesy of Watches Of Knightsbridge & Keystone.
This is of course only speculative... but for IWC/Zwyro starting along the same lines in 1969-75 might very well have been the first step going towards serially produced movements with high-end finishing. And the Cal. 89 is for a particular reason the perfect playing ground for this development: Sturdy means that there is also a lot of metal involved, or in other words, material that can be removed without tempering with the functionality too much.
Another piece of evidence that the 'Zwyro' 89 was the petri dish for upcoming production models is IWC's ref. 5500. Introduced in 1977 in a limited run ([source]), just two years after the 'Zwyro' 89, these were complicated pocket watches with elaborately finished movements (Cal. 9721)... Movements that in their layouts were very similar to the Cal. 89:
A rare and early IWC ref. 5500 perpetual calendar pocket watch with hand-engraved caliber 9721. Photos Courtesy of Christie's Geneva.
I would thus argue that the 'Zwyro' Cal. 89 is not just an obscurity or an oddity, an outlier to IWC's serial production or a Technical Director's fever dream but is actually of historical importance. Robert Zwyssig and IWC picked up on the evolving trend of movement decoration and skeletonization - that by the way is as relevant today as ever - and tested the procedure on some of the most forgiving movements in their stable. It shows you again and again why the Caliber 89 is a personal favorite and one of the most pivotal time-only movements of the last Century!
Acknowledgements
I'm delighted to have even been able to write this story and that was only because a group of collectors made me aware of these extraordinary timepieces. I would thus like to thank owner of the displayed piece Dongyi (@Dongyi212) & collector James (@slowjms) for the photos they shared and the initial leads on this story!
Footnotes
* Forums are treasure troves of yesteryear. So much great and original research dates back to these early format amateur short-form journalism.
** For me it is unapologetically classy putting a well-decorated movement behind a solid case-back.
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