Zenith Rainbow Chronograph El Primero Review

gup502 shares a personal, in-depth review of his Zenith Rainbow Chronograph, a watch that has become a cherished part of his collection after years of searching. His detailed account covers the watch's technical aspects, design choices, and historical significance, providing a valuable long-term ownership perspective for fellow collectors.

Funny enough, nowadays this is the watch that has won most of my wrist time.  Probably because it also took me years to find a good second hand one.  Finally it was located in Germany.

Anti-glare coating on both sides of the sapphire glass seems to be the standard with most Zenith watches.
No see-thru glass but that is what I prefer for this watch as the movement is not really very appealing at all, i.e. in terms of craftsmanship unlike other manufacturers who want to show off their skills in the construction and polishing skills, Zenith has always been down to earth in ensuring just the technicality being highly accurate and functional.
But it is a legend in its own right.  Zenith racing to be the first to launch a chronograph movement beating at 36,000 back in 1969 and successfully knocked Breitling and Heuer off the competition arena.

Interestingly back in the old days when this watch was available on the market, it was hardly a great success.  Was it because of the size at 40mm or was it because of the dial face with the eye-catching combination of colours, no one really knew.  Back in those days, I remember picking up any Zenith, they gave me a sense of robustness.  It must have been the solid bracelet and the buckle.  Come to think of it, the butterfly folding buckle has always been the most comfortable one in my personal experience and it was already a standard feature back in the late 1990s with Zenith watches.

The challenge comes in sizing the bracelet.   It is not an easy task and I would suggest to leave it to the true professionals at Zenith even if you are a very capable in replacing straps every season with your collection.  The good thing is once adjusted correctly, it bonds closely to your wrist.

This time piece appeals to me not only because of the history (designed for the French air force? Sorry I never thought they were an elite group) nor was it because of the bold design but for its accuracy.  Mine has been running 1 sec fast per day. Yes, I am crazy enough to check it for 30 days. In a calendar month, it runs 30 seconds fast!  It is true that if accuracy is something one looks for in a watch, quartz is the way to go.  However, the amazing fact is found in a mechanical movement.

People have been complaining about issues with the chronograph.  Zenith has admitted the component in the early Rainbow movements that resets the hands to zero is not perfectly executing its function.  The engineering team at Zenith have designed a replacement component to ensure perfect reset and restart so that the movement can truly claim itself a flyback.  Such a replacement can be requested at any of the future service intervals.

The bezel is not designed for diving though the watch is water resistant to 100m.  Should one have a need to dip into the great ocean, this watch will not fail.  I was told as far as water resistance is concerned, there is nothing to worry about the pushers.  It is true that the crown guard looks a bit out of place, somehow that contributes to the unique styling of the watch.  I know I am biased.

The lums on the dial face will soon fade but why bother.  It is going to be a vintage. I'll be happy to let them turn into a colour which takes years to achieve rather than getting them all replaced.

40mm may seem perfect even for today's standard but the truth is the watch does look a bit smaller because of the sizing of the bezel.  The dial face is only 30mm in diameter. Is it the perfect size?  I'd leave that to those lucky individuals who own this time piece to be the judge of that.

I have done a bit of research on whether the colour green, yellow and blue contribute to the functions of the watch.  To date, the answer is negative, apart from these colours do represent certain height and visibility for pilots who should be familiar with the aviation codes, nevertheless these colours are no way exhaustive.  My conclusion is therefore they are there as part of the aesthetic design rather than functional.

Perhaps, this was an under-rated time piece back in the late 1990s but the value of it has already gone up.  I am happy to own one eventually and this is definitely one to keep for quite a long time.

Thanks for reading.