Two ‘60’s chronographs born two years apart: the older of the two, a youthful upstart; the younger an experienced older hand. We have met examples of both of these watches before (here and here) and so the purpose of this present entry is to provide a comparison between two contemporary examples of their genus as I work through the renovation of each.

The Seiko 45899 one-button chronograph (left, above) was introduced in 1964 (this one dating from November of that year) to coincide with the Tokyo Oympics. Its movement was based on the established Crown 560 calibre, and in this incarnation featured a pillar wheel design to orchestrate the start, stop and reset of a single centrally-mounted chronograph hand. The absence of an elapsed minutes sub-dial was compensated by the inclusion of rotating bezel, the idea being that you aligned the triangle with the tip of the minute hand upon starting the chronograph.

The Breitling Top Time 2002 was a model series introduced by Breitling to exploit the ‘staggering purchasing power of the youth market’. This watch was fitted with the Venus 188 movement featuring not just running seconds but integrated elapsed minutes. The start/stop/reset cycles are orchestrated in this case by two push buttons: one at the 2 o’clock-position to start and stop the chronograph and a separate reset button at the 4 o’clock-position.

These two watches have weathered their life experiences quite differently: the Seiko looks to have emerged from the past 60 years remarkably unscathed whereas the Breitling looks like it has lived a life filled with incident. However, the Seiko was not without its issues: its bezel was seized and once I’d freed it, I noted that the mid-case bore some scars from previous removal attempts. Cosmetically though it was otherwise excellent, barring some fairly ingrained patination to the movement. The Breitling arrived with its crystal detached, its stem missing and an index ring with most of its printed markings worn away. The movement had also suffered from the effects of water ingress, the result of the crown gasket having escaped from the confines of crown due to a missing retaining washer.

The Seiko employs a three-part case with the movement accessed via a press-fit case back; the Breitling on the other hand uses a one-piece case with the movement accessed from the front, requiring the crystal to be removed.

The contrast in external condition is also clear from the dials: the Seiko is pretty much flawless; the Breitling very grubby, particularly around the subdial hole areas.

In surveying each movement, we can note the two proprietary antishock systems fitted to the balance wheels: the Seiko employs its Diashock system, introduced in the late 1950s and sustaining to the present day whilst the Venus 188 in this installation employs Breitling’s own Breitling Shock system in place of the more familiarly ubiquitous Swiss Incabloc setting.

With the two movements partially dismantled, the extent of the patination in each becomes clearer.

The water damage on the Breitling is particularly clear around the setting parts as viewed from the dial side. Where the Seiko just looks quite heavily varnished in places, the Venus setting wheels are slathered in Marmite with plenty of, albeit superficial, surface corrosion evident throughout.

In deconstructing the movements, two key faults or flaws presented themselves in each: with the Seiko 5719A, as commonly seems to be the case, the hammer c-clip had a stress fracture at its apex and would not be reusable. Fortunately, new replacements are still available. The second more serious issue was a very significantly out-of-flat mainspring and this too would need to be replaced.

With the Venus 188, the main issue was the rather extensive corrosion to the chronograph operating levers but while this was ugly, it was not affecting their operation and would respond to cleaning with a glass fibre brush in due course. The second more important problem did not become evident until I was reassembling the movement after cleaning: the screw holding the minute recording jumper was worn to the extent that it would not gain purchase on the rest plate beneath and could not therefore be tightened down. I was able to sort this problem in due course by ordering a replacement screw and as a precaution a replacement jumper rest.

These two movements are rather more complex in their design and construction than a simple three-handed calibre, the Venus in particular, but both came back together without too much of a struggle, aided I think by the familiarity of having worked on examples of both previously.

At this point in proceedings, both movements were running, and both achieving healthy amplitudes with noiseless timing curves and negligible beat error. However, both movements exhibit an increase in rate with decreasing power as the amplitude drops. The Seiko performs less well in this regard but otherwise the two movements are closely-matched in terms of their positional variation and overall levels of performance.

In taking timing measurements of each, I referred to available lift angle databases in setting up the timegrapher. The Venus 188 is essentially the same movement as the Valjoux 7730 and I used the published lift angle of 48 degrees of the latter in timing the movement. That yielded a best amplitude of around 285 degrees for the Breitling with the chronograph disengaged. For the Seiko, I initially used a default value of 52 degrees because no published lift angle data are available for the Crown-based 57-series movements. For this reason, I decided to measure the lift angle using the procedure I have described previously and obtained a surprising value of 58 degrees. The highest amplitude I measured for this movement was 312 degrees dial down with the chronograph disengaged. For those of you who might be interested in such geekery, I posted a YouTube video recently showing how I obtained this result for this movement.

Moving to the outward facing components, both watches needed some work. The dial and hands of the Breitling were very dirty but responded well to my ministrations. The complete lack of effective water resistance was addressed by a new crown gasket topped with a substitute retaining washer and a fresh gasket for the upper pusher. The lower pusher resisted my attempts to fit a replacement gasket (nothing fitted) and the pusher tube was so worn that I would not have been able to remove it without risking its destruction. In the end, I left the reset pusher without a gasket and advised its owner that although the water resistance of the watch overall would be much improved, a vulnerability still existed.

The Seiko dial and hands were in excellent condition and needed only a light clean. The main casing work focussed on freeing the bezel and fitting a new bezel spring, rebuilding the crown, fitting a fresh gasket in the process and fitting a new gasket to the pusher.

With both movements running well, I was able to refit the remaining components, test all the functions and recase them.

I had already fitted a new acrylic crystal to the Seiko but with the Breitling being a front-loader, a new crystal was the final piece of the jigsaw.

It has been interesting to revisit these two models: the Breitling is a lovely thing, its frayed edges enhancing its charm. For me it is a perfect size and the absence of an external bezel allows it to slip easily under a shirt cuff. My own example of this watch has an all-silver dial but the panda dial in this one really adds another dimension to its personality.

The Seiko is also black-dialed, in contrast to the silver-dialed watch that I owned. Mine had a bakelite bezel where this one has a 62MAS-esque steel turning ring with a black-anodised aluminium insert. It is a very handsome watch and elicits a slight twinge of regret that I sold my own.

The Seiko 45899 one-button chronograph appeared in a number of different configurations, adopting the modern model number system along the way (as 5719-8980, -8990, -8991 and -8992 plus 5717 dated equivalents) and survived until 1968 when the new automatic 6138 and 6139 chronographs were introduced. The Venus 188 morphed into the Valjoux 7730 when Valjoux absorbed Venus and survived in subsequent evolutions through to the present day in the form of the Valjoux 7750.