Tourbillion or Chronometer: if accurate time keeping is the goal

[On_Time]

Hi

I am considering a choice between a tourbillion watch and a chronometer (JLC Master Date Tourbillion 39 vs. Patek Phillipe 5270)

Accurate time keeping is what I desire for discussion.

I am uncertain which mechanism (tourbillion or chronometer) would be expected, in a general sense, to give you "better" i.e. more accurate time keeping.

Of course, I am referring only to (high end) mechanical watch and not hybrid like Grand Seiko Spring Drive with an inner heart of quartz crystal.

Look forward to your opinions.

Thanks

On_Time

[v76]

The tourbillon was originally designed for pocket watches where the PW would be "12 up" most of the time. To compensate for the escapement not being horizontal and hence to minimize the unequal acceleration due to gravity effects, the tourbillon was quite effective.

Before the advent of CAD/CAM, the tourbillon was an expression of the watchmakers art, skill and craft beyond actually being useful in PWs. However, in wristwatches since the watch face can assume different orientations with respect to a reference plane, the tourbillon is a lot less effective. One could however argue that a multi-axis tourbillon, gyro-tourbillon or an escapement mounted on gymbals (so that the escapement is always horizontal, like the one Zenith's developed - and in my mind, the best solution) could provide a potential solution to this problem.

Having said that, a very well designed movement, finessed and adjusted by a good watchmaker is more than enough IMO, and a tourbillon is overkill. I do however crave things like constant-force escapements, near-isochronous mainsprings etc. (wish I could afford a Heritage Watch Manufactory Tensus *sigh*).

[drewmcd24]

What about the new JLC Spherotourbillon? It combines a multi-axis tourbillon with the dual wing power train concept of the Duometre line. From what I've read that combination should have a measurable effect on the accuracy of the watch. Is that true, or is it marketing fluff? Either way, that is one pretty watch.

[On_Time]

Thanks

I remain uncertain of the net effect(s) of the tourbillion on the wristwatch accuracy.

The reviews claim the sphero-tourbillion to be off by only 1 second a day.

Any one knows of the claimed / reviewed accuracy of a high end chronograph?

The JLC Master Tourbillion 39 has the 978 movement with which JLC won the time keeping comp so that's why I am interested.

The question remains: which one (everything else being equal) would give you more time-keeping accuracy: a tourbillion or a chronograph ???

Regards

On_Time

[HPoirot]

I would imagine most of the people on this forum would not have enough exposure nor experience with the various incarnations of the tourbillon to give an accurate answer.

But i will agree with what v76 said: The tourbillon was originally designed for pocket watch use, and loses it's effectiveness when translated to a watch. (Logically speaking, not based on any studies)
A chronometer, on the other hand, would have gone through the rigorous testings and would therefore seem more accurate.

Furthermore, tourbillon watches are now being marketed more as an aesthetic feature than a horological one, while chronometers (are they the same as COSC?) are marketed purely on their accuracy. Perhaps they're aware of it's redundancy in wristwatches?

Based on the 2 points, my deduction is that a chronometer would be more accurate than a tourbillon, even if only by a little.

[drewmcd24]

The question remains: which one (everything else being equal) would give you more time-keeping accuracy: a tourbillion or a chronograph ???

Regards

On_Time

I think you're mixing up two different terms. A chronometer is just a watch with a COSC certified movement that was tested to run between -4 an +6 seconds per day. A chronograph is a complication that allows you to measure elapsed time.

Neither Patek or JLC submit their movements for COSC certification, so neither of the watches mentioned in your OP are chronometers.

I don't think anyone can give you an unequivocal answer, but between a watch with a tourbillon complication and one with perpetual calendar and chronograph compilations, the tourbillon probably has the greater potential for accuracy. A tourbillon is specifically designed to deliver a more stable rate by eliminating the effect of positional variance. As others have said, it's debatable how much of a difference it actually makes in a wrist watch. I don't know much about the movement in the PP 5270, but in general, regular chronograph use can cause variations in the rate of the watch.

So that's why I suggested the JLC spherotourbillon. It has a multi-axis tourbillon and a dual wing power train. Both are complications meant to deliver a more stable rate. If you're looking for a high-end watch based on its potential for accuracy alone, it would be a good bet.

[Tick Talk]

Of course a tourbillon chronometre is the answer! JLC won the re-enacted Observatory Trials in 2009 with such a beast, although they mysteriously went absent for the second running in 2011. Nevertheless, tourbillons still dominated the contest. Also, the Geneva Seal organization has upped the (pathetic) COSC chronometer standards with their newest requirement to test complete watches rather than movements in isolation.

[blansky]

Seriously, if extreme accuracy is your goal get a quartz.

Mechanical watches are about beauty and exquisite engineering. Enjoy their magnificence, and don't spend so much time worrying about plus or minus a few seconds a day.

[On_Time]

I would imagine most of the people on this forum would not have enough exposure nor experience with the various incarnations of the tourbillon to give an accurate answer. .... Based on the 2 points, my deduction is that a chronometer would be more accurate than a tourbillon, even if only by a little.

I tend to agree with this observation (no data available, just deduction).

Sure, the sphero-tourbillion is supposedly immune from interference due to its twin barrels etc... but the garden-variety tourbillion (movement 978 in JLC Master Date Tourbillion 39) actually won the comp while significantly cheaper than the €200,000 price tag from the sphero-tourbillion.

However, the chronometers did not win that comp.

That's the reason the JLC Tourbillion 39 is on my acquisition list.

I did say somewhere that I wish to discuss non-quartz watches only [excluding even hybrid Seiko Spring Drive]


Regards

On_Time

[Navitimer]

Seriously, if extreme accuracy is your goal get a quartz.

Mechanical watches are about beauty and exquisite engineering. Enjoy their magnificence, and don't spend so much time worrying about plus or minus a few seconds a day.

I respectfully disagree.

I am interested in mechanical movements for their engineering, not just because they have been polished by an old man with a sharpened stick. At this level of horology it is wrong to let manufacturers off the hook with accuracy. Accuracy defines everything about a watch. These manufacturers made their reputations based on accuracy and longevity, this is somethign they'd dearly love to forget so thay can knock out watches which are no more accurate than a modern ETA. The accuracy shows the level of precision in the manufacture, the care taken to adjust the watch and the result of the often 'in-house' movement design. Each of these factors have an effect on the watches rate.

Now both Patek and JLC are known for accuracy and the Patek seal even very loosely applies a standard. This commitment to accuracy was the defining factor in my purchase of a patek Calatrava over other brands.

Sorry to go a bit off topic... :)