Zenith has been doing wonderful things since Julien Tornare took over at the helm in 2017, somehow managing to push the brand forward with new additions to their product range, while dutifully honoring their heritage in a tasteful manner. Tornare is surprisingly frank about the prevailing forces in the Swiss watch industry, and Zenith’s place within. It’s an attitude that serves the brand well, and one that confronts the realities of fostering growth while being the custodian of their past. As interesting as the present may be for Zenith, there are particular moments of their history which highlight just how compelling the brand can be.
One of the unique things about Zenith’s approach is their willingness to lean into their heritage alongside the modern components of the same collection. It ties their past to their present in a way that creates a throughline for the original vision, and how they carry that forward. A modern brand must be more than just their past, but that’s a discussion for another day (or a podcast). Zenith’s history is full of incredible watches, many of which have slipped through the cracks, presenting opportunities for enthusiasts to discover the brand in sometimes unexpected ways. There are many great examples from the ‘60s and ‘70s, but this review will focus on a watch from 1997, just prior to the Thierry Nataf era, representing the best of the brand’s tool watch chops. The watch is the Rainbow Flyback Chronograph, and its story is full of unexpected turns.
The History
The Zenith Rainbow collection of chronographs dates back to 1992, when it was launched as a successor to the De Luca (another gem of Zenith’s history). The Rainbow used both El Primero and Elite calibers across a variety of configurations meant to be a sport watch. The crown and pushers were screw-down, the crystal was sapphire, the bezel could be fixed with a tachymeter scale or rotating with elapsed time, and the 40mm case was waterproof to 100 meters. It was a capable watch in its day, and quite popular upon release, squaring up nicely against stalwarts like the Omega Speedmaster and Rolex Daytona (which used a modified El Primero at the time).
We see the word ‘rainbow’ thrown around quite a bit these days, generally in reference to a colorway on the dial or bezel incorporating some variation of ROY G BIV. However, Zenith’s use of the word had nothing to do with a colorway. Instead, the name honors the ship that won the 15th America’s Cup sailing competition in 1934, beating out the UK based challenger, Endeavour (under somewhat controversial circumstances). The Rainbow was the defender for the US team, who won the 14th Cup in 1930 with the Enterprise. The caseback of the watch bears a depiction of the J Class yacht, and the word Rainbow inscribed above.
Exactly why Zenith used this ship as the name of their new sport watch collection is unclear. There are suggestions that its underdog status mirrored that of the El Primero coming into the ‘90s, but I think there’s more to the story than that. We’ve reached out to Zenith for clarification, and will update this article with any insights we receive.
UPDATE: This is what the Technical Director of Zenith, Laurence Bodenmann had to tell us about the origins of the Rainbow name:
Excellent question : this name was chosen without any doubt to convey both the ‚chic and sporty‘ universe of yachting into this powerful line, which was to be the racy yet elegant one at the beginning of the 1990s already (the Rainbow line actually dates from 1992 and was fitted with the regular El Primero movement without flyback at the beginning, to be completed in 1997 with the flyback variant which inspired our 2023 Pilot).
The brochures from the time depicted the Rainbow defender from 1934 as ‚the lord of the America‘s Cup‘ – because of lines, or the fact it was built in connection with Sir Harold Stirling Vanderbilt, from the famous Vanderbuilt family? Some of the mystery remains as to why this specific defender was chosen, but it might very well have been thanks to its name, which might have sounded better and more classy than others, and the fame of its launcher.
The watch was popular enough that the French Air Force tendered a request to Zenith for a modified version of the rainbow which could be used by their pilots. The request would have Zenith producing and delivering 1,000 of the watches over the course of 4 consecutive years. This would be the impetus for the Rainbow Flyback, a revised Rainbow meant to meet the needs of more extreme conditions faced by members of the French Air Force. The changes were significant, altering the overall personality of the watch enough to separate itself from earlier variants at a glance. Not only did Zenith alter the functionality of the watch, adding a flyback complication to the chronograph, and ditching the screw-down elements on the crown and pushers, but they also changed the design of the dial to better suit the new demands it would be placed under.
In 1995, France elected Jacques Chirac to the presidency, and in February of 1996, he somewhat controversially ended military conscription. This gesture was acting on the broader ideas put forth within the Defense White Book put together by right-wing Premier Edouard Balladur, and the subsequent study The Army of the Twenty-First Century by General Jean-René Bachelet earlier in the decade. The fallout from these moves was wide reaching, and if I’m being honest, out of my wheelhouse, suffice to say, military size and spending was deeply impacted (annual Title V allocations slipped from $17.4 billion in 1996 to $13.3 billion in 1999), and as it pertains to our story here, the contract with Zenith to produce watches for the Air Force, was ended before it ever really got off the ground.
Thankfully, a handful of the watches did make it through to production and were ready for testing before change of direction. Zenith made the decision to make the watch commercially available, and would reveal the watch publicly for the first time at Baselworld in 1997. The watch designed for the Air Force would be joined by a less colorful black variation a year later. As mentioned, this was just prior to the Thierry Nataf appointment in 2001, who took the brand in a very different direction, leaving the Rainbow Flyback very little time to flourish. Around 5,000 of the colorful ‘military’ examples would be produced, and another 4,000 of the black dial ‘civilian’ variations produced. With a closer look at these watches today, it’s easy to get caught up in a ‘what could have been’ line of thought, had Zenith gone a different direction in 2001.
It’s worth noting that another of the all-time great tool watches was also released in 1997 by Sinn called the EZM1, kicking off a spec-built collection that persists to this day. I don’t think Zenith could have taken a similar approach, as they are a very different brand, but I do think a proper evolution of this design language was denied to us. Thankfully, it’s never too late to pick a good idea back up, and Zenith has proven adept at just that.
The Watch
So the watch has an interesting backstory before it’s even entered the public eye, with plenty of lore to live up to. In many ways, this is a watch of its era, which can be a fine line to walk, but in my experience, the qualities that define it as such, are sorely missed in today’s modern tool watches. As a result, this is a watch with charm and character, as you might expect, but more importantly, it holds up incredibly well in a practical sense.
Some of this comes down to the watch’s stature. The steel case is labeled 40mm in diameter, but in reality it’s a touch under that. Thanks to a flat crystal the total thickness is held in check at 12.5mm, a rather impressive figure when you consider the complications at work inside, and the price point both then and now. Finally, the lug to lug distance is 46mm, with a short, but odd lug design (more on that later). But those are just numbers, and very often don’t tell the full story of wearability. What really makes this watch fantastic on the wrist is the shape of the case profile and the caseback transition.
The sapphire crystal here is flat, and gets a double AR coating at that, making for excellent visibility to the dial, a hugely appreciated feature that lends a modern feel to the watch overall. Aside from the crystal, there isn’t a flat surface to be found on the case. The sidewall bows out ever so gently, with the couture even continuing on the lugs. This organic shape flowers into the softly bellied caseback that rests in the small of the wrist. It wears very similar to a Daytona in this sense, not only sharing a similar set of dimensions, but in managing to find a certain magic in its case design that allows the watch to simply melt into the wrist.
The design of the case itself is neatly hidden under the toothed bezel assembly, accentuated by the lug integration to the case. The lug design feels tacked on to the rounded the case, protruding completely parallel to one another. If I have one niggle with the design, it is this area of the case. The transition feels a bit jarring, and slightly inelegant to my eye, but it perfectly suits the bracelet design, and taken as a whole it somehow works better than when merely focusing on the lug and case.
Because of the lug and bracelet design, this isn’t a watch that suits a wide variety of straps, if only because it accentuates the lug irregularities all the further. A bit like a Submariner with a muscle case not looking quite right on anything but its bracelet. The case, lug, and bracelet work best taken as a single unit. Additionally, the end link is not fitted between the lugs with a regular springbar, but rather the same style of pin that holds all the other links in place. It is literally treated as a single unit with the case. Thanks to the drilled lug it can be removed, but fitting a regular springbar presents a very narrow gap through which to thread a nylon strap.
A final note about the case to mention the crown and pushers, which have been freed from any screw down apparatus that shackled them on the regular Rainbow chronographs. They form a tight group around a mounded crown guard, and each is tabbed at the end. It’s easy to use, and the grouping doesn’t have the curvature of a more traditional case shape, so while they look a bit cramped on their own, once again it works in the context of the whole.
The dial is framed by a rather unique bezel assembly and insert. A rather aggressive tooth pattern provides a nice level of grip, a departure from the standard coin edge found on the rotating dive bezel of the standard Rainbow chronograph (when so configured). This is likely a move made for the French Air Force as a means to more easily manipulate the bezel. The aluminum insert is fully indexed, another common feature among military watches, with the first 20 minutes highlighted in red. A telemeter is present as well, though it’s been moved to the rehaut under the dial.
The telemeter can be used in conjunction with the chronograph to provide an approximate distance between the wearer, and an observed event, based on the speed that sound travels (through air). For example, if the wearer is quick enough to start the chronograph upon observing a distant blast, and stop the chronograph when the sound arrives, the telemeter will help you discern the distance between you and said blast (assuming dry-ish air and normal temperature). The flyback functionality of the chronograph would allow for quick successive timing of such events to help the wearer hone in.
The dial of the Rainbow Flyback is the real star of the show, if you ask me. It’s a symphony of scales, numbers, sub dials, and colors, and it all comes together way better than it has any business doing. Arabic numerals rendered in tritium circle the dial, which simultaneously hosts a running seconds at 9 o’clock (fully indexed, at that), a 12 hour totalizer at 6 o’clock, and a ‘big eye’ 30 minute totalizer at 3 o’clock, which is broken into colorful 5 minute segments. The minute totalizer gets a helping of green, yellow, and blue to help quick get a read on your timing status at a glance, serving as the clear focal point of the design. Further aiding this are the timing hands (sans the hour totalizer), which are presented in bright orange.
The design is as functional as it is visually compelling, even for civilian use. Its intentions are clear and somehow everything is easy to read and well spaced out. My favorite detail just might be the date aperture at 4:40, though. This has long been the most contentious element of El Primero equipped watches (recently, at least), but it’s also something of a calling card. The Rainbow Flyback leans into this placement fully, and it pays off. The window itself is trapezoidal, with a thin white outline that allows it to pick up the seconds index without skipping a beat. The section of the index has been moved to the outermost edge of the white frame around the aperture, so if your timing is stopped in this section, you’ll still be able to get a precise read on your timing (or your distance measuring).
The Zenith mark at the top of the dial is set over the scripted El Primero label, something generally reserved for Heritage models in their lineup these days. The civilian all-black version of the Rainbow Flyback gets a Fly-Back label, which is eschewed by the colorful Air Force variant. All this in reference to the automatic chronograph movement within: the El Primero 405 caliber.
The original Rainbow Chronograph received the standard EP400, but with the addition of the flyback function to suit the needs of the Air Force, this became the EP405 in the watch you see here. The movement has since been updated to the EP405B and is in production to this day. The 405 remained a high-beat movement, with a frequency of 36,000 vph, beating ten times per second. While this allows for a greater level of accuracy on average, it comes at the expense of durability over time, which is the reason Rolex slowed the movement down 28,800 vph for use in the Daytona.
A flyback chronograph operates exactly the same as a regular chronograph, with one added ability, which is to basically reset and restart on the fly. Timing is still started with a press of the button on top, and can still be stopped and rest as normal. However, with the timing actuated, the reset button on the bottom can be pressed to instantly restart the timing from zero. Longines was the first brand to use this function in the legendary 13ZN back in the mid ‘30s. The complication was found particularly useful by WWII pilots, and was an essential part of the Type 20 formula put forth and formalized by the French Ministry of Defense.
The El Primero 405 within the Rainbow Flyback offers 50 hours of reserve, and its action holds up incredibly well today. Starting, stopping, and resetting of the chronograph feels sharp and concise, without any clunkiness to the actuation. It rivals the feeling of the newest flyback chronograph from Zenith, the Pilot Big Date Flyback, which has a buttery soft feel to its pushers. We’ll have a hands-on review of that watch coming soon, but it’s worth pointing out that the Pilot Big Date Flyback in steel uses the very same color scheme in a far more subtle way around the rim of its 30 minute totalizer, no doubt a nod to the Rainbow Flyback.
A quick note about winding and setting, which is slightly unusual if you’ve never handled an El Primero before. The crown is not screw-down, as mentioned, and the setting of the time happens on the first stop, while the quick date set is handled on the second stop. It does not hack, so don’t expect to be setting this one with time.gov levels of precision.
There is no exhibition caseback here, but rather a simple engraving relief with a stylized Rainbow Fly-Back label above a shield with stars bearing the Zenith brand. It looks like it could have been lifted straight off the cover of a comic book, advertising the arrival of a superhero. It’s a final bit of character that really throws the whole thing over the top in terms of personality. Sure, the case and lugs are a little wonky, the dial is a cacophony of detail that can be tricky to make heads or tails of, and the function set is unique, but as a whole, the watch comes together remarkably well, and presents a compelling look at tool watches in their prime. This watch is more than the sum of its parts, and it’s built on a mountain of interesting history and lore.
The Zenith Rainbow Flyback can be found for well under $5,000 these days, and trust me, this is a lot of watch for the money. The aesthetic is clearly of another era, but there is so much to discover with this watch, on top of the generally amazing ergonomics, which make this watch truly everyday approachable. That might not be the best idea in practice, thanks to the high beat movement that’s going on ~26 years now, but with proper servicing this watch can still provide plenty of real world joy beyond the watchbox.
That’s really the sweet spot for a watch like this. It’s interesting enough to tell stories about, but accessible enough to use without having to be too precious about. There’s not much hype associated with it, and you’re not likely to spot many at your local meet up.. It’s a watch you can enjoy just for what it is. And what it is is truly something special.