Jaeger-LeCoultre

If you aren't already aware, JLC incorporates a nonpareil shock-absorption system in some of its Extreme series watches. The Extreme World Chronograph, the Extreme World Alarm and the Extreme Tourbillon include this feature. These watches are actually constructed using two cases, an inner case made of tiatnium, which houses the movement, pushers and crystal and an outer case comprising the lugs, the bezel and the caseback. The outer case is made of stainless steel, titanium, platinum or rose gold, depending on the model.

JLC states that the direction of a shock which is most dangerous to a mechanical movement is shown in the photo below as "Z", and that the Extreme Series' shock absorption system can soak up 50% of this force before is gets to the movement, due to the springs and air. Further, JLC states that titanium was used not just for aesthetic reasons, but due to its lower density and overall weight compared to a heavier metal, since the force imparted to the movement is equal to mass multiplied by acceleration [ F=M*A ].



The inner case rides on a cushion, basically a sealed chamber filled with 4 springs and air. The pictures below, from a prior post on this website, with credit to the original poster, shows how this arrangement works.





So, how does this work in the real world?

This photo shows the watch as it sits with no force being exerted on the inner case, hence, no deflection of the inner case inside the outer case.




This photo shows the watch with force being exerted on the crystal with my thumbs. The amount of force I used is probably equal to the maximum amount of force an average person could exert using both their pinky fingers pressing directly down on the crystal. I certainly could have pushed harder using my thumbs, but was reluctant to press any harder on the crystal for fear of damaging it. When the force of my thumbs is released, the inner case moves back to it's original position, not with an instant snap, but more like how a car's front end rebounds after jumping off of it's front bumper. The total possible range of motion is probably 3-4 mm, with maybe 2.5mm shown here.



I haven't seen this topic addressed before, so I hope this post does a good job of explaining it to anyone who is interested. Knowing this, I always do a good job of rinsing the watch, especially after submersion in salt water, because obviously the salt water will flow in between the two cases to some extent.

I had not thought about this aspect fo the EWC in a while, and it is good to have a refresher.  The shock absorption was one of the many factors that pushed me to get the EWC -- was that true for you as well?  The case within the case design is the key reason for the thickness and diameter of the watch.  These Extreme JLCs are not big merely for the sake of being big, which is not always the case with the many huge watches that are sold these days, as we know.

Good point about rinsing off the EWC after a salt water swim.  Thank you.  I wonder if the case within the case design makes these Extremes more vulnerable to water penetration...something I had not considered before. 

Have you seen the new JLC book on their extreme watches?  I am very eager to see a copy. 

Thanks for this post.   

Best,

respo

Hi Everyone,

I didn't heard about that book. Wo has informations on it. I'm very interrested about it.
Best.

Marc

jlc.watchprosite.com

Have a good read.

Best,

Nicolas.

post, this is definitely great to know! Thanks for sharing the photos!

Best,

Filip

No message body

Respo: yes, the extra safeguard of this system was a factor in my decision to buy this watch, and this for me, along with the quick-change strap system and 100m WR, solidifies the "wear-it-wherever-and-forget-it" aspect of this particular piece. Even those to whom a 46mm watch is unwearably large will likely agree that the shock absorption system is a very bold and purposeful innovation.

I wonder which complication of the Extremes can withstand the most shock before failure, the World Chrono, the World Alarm or the Tourbillon/GMT? And which metallurgical combination provides the most shock resistance, the Ti/Ti of the Rossi World Alarm or the Pt/Ti of one of the World Chrono editions, or an outer case metal with a density in between these two "extremes"?

I have not seen the Extreme book, I haven't even been into an AD in a few months, and certainly not into a boutique. (I am jealous of your trip to Mizner Park!) If I saw Messr. Lambert I would hope to have a few words with him, but I think I'd probably scream like a teenage groupie in the 60's at a Beatles concert

When I saw M. Lambert, I was on my way to someplace where I do not wear nice watches and so I had no watch, let alone a JLC, on my wrist, even though I was traveling with the Polaris on this trip.  And I am almost NEVER without a watch!  Yes, it was a little like seeing a rock star -- very funny to me afterwards.  He was wearing a Squadra Chrono, I think a Worldtime limited edition. 

I forget if I have read anything about the Extremes and anit-magenteism.  I am wondering if the design also offers any additional anti-magenetic protection as well...

My EWC is with JLC right now for service, and I must admit I miss it terribly.

Best,

respo

  

Jerome Lambert is a very friendly gentleman, and I'm sure you had a great moment, speaking with him.

If all works well, I will meet him in less than 12 days, now...

Will try to wear a real watch, then.



Best,

Nicolas.

I was like, "No really, I do own a real watch.  I do, I do!"

I am sure you won't have any such problems, Vlad, the Prince of JLC.

Best,

respo

thanks for sharing

J

No message body

but closer to 1 mm.  How are you getting 2.5 mm?  Even without any compression I only have about 1.5 mm available. 

as you can see from the photo with the cushion compressed, my hands were full!

I chalk this up to using inches and feet my whole life to measure distance! I'm sure both watches are the same.

I really like the EWA, especially the Tides of Time version in SS/Ti.

So perhaps your estimates should be divided by 2 or so?

as a "yardstick" (haha). 14.5mm, I think. I have a set of Vernier calipers, but they're buried somewhere in the garage. So I think you are right, maybe the total range of motion up and down is around 3mm, 1.5mm in either direction.

Informative post!

 

Love this kind of posts!

 

 

Unfortunately I find the Extreme watches to big for my wrist.

 

Would love to add the Tides of Time to my Memo theme…

 

 

Best

 

Blomman

...shock is a very quick application of an acceleration. It's not just the magnitude of the 'g's, it's the duration and rate of loading that matter.

 The shock absorber here is air which will dissipate the shock energy as heat. The problem is that the damping effects of air is proportional to velocity of the inner case movement. So to be effective, it would have to be tuned for a certain range of velocities. This can be seen by the fact that if you slowly press the case, it compresses. So at low velocities, it has a lot of movement, at higher velocities, it will almost lock up - not much damping.

Or another way to look at it is: a really short sharp shock will not cause much movement and any movement will be very rapid. In these circumstances, I wonder how effective the damping system will be?

All this is rather esoteric but unless the data from JLC is available, this system makes me wonder. I am not saying it's ineffective, as it has to be better than a completely rigidly mounted watch (but then how tight do you strap your watch ). But I wonder whether the complication brings any practical benefit....

Then again, all is a moot when you have 2 massive crowns hanging off the case.

And I hope my thoughts will come across to you as accurately as possible given my imprecise wording. I, also, would love to see any data that JLC might have, though I assume this is not going to happen.

It feels almost like the shock absorber on a car. I don't know what part in that the stiffness of the 4 springs play or what part in that the sealed chamber of air plays. I assume that the damping of the system is tuned to only operate above a certain threshold force that JLC feels is safe for the movement to soak up on its own.

I know that at a launch party for the watch, guests were able to strap on the watch and slam their hand onto a table which contained an accelerometerwhich then gave an indication of the shock transferred to the watch. The winner was a martial arts expert who imparted 1470 G's of force to the watch, the EWC having suffered no damage. For those like me who might not be able to relate this to anything, here is a quote from the launch review which can be seen here in Part 3 of a previous post on this forum:

www.network54.com

"A watch however can subject to a level of impact of 50 - 100G of shock when playing golf, Ice climbing as much as 200 - 300G and competitive Mountain biking as much as 400 - 500G and Extreme sports impact can be as high as 600 -700G"

I assume the length of time across which the G forces occcur matters too, the watch may be able to withstand 1470 G's for a few fractions of a second, but probably not ten minutes in a centrifuge at 1470 G's.

Any insights you might have about the launch party test or anything I said above would be appreciated, and I hope I don't come across as saying "It must be super-effective because JLC can do no wrong."

Though I feel, like many advances in horology, if this setup only takes a step (rather than a great leap) towards a more shock-resistant movement, I'm sure many would agree that it is worth it for JLC to pursue (and, to me, worth the larger case size.)

Thanks,
Adam

...I think I've seen that report before...?

There's no doubt that suspending a movement inside a case is going to aid the shock resistance of a watch (after all that's what some of the G-shocks do! ) and as you say it does provide good justification for the size of the case.

My comments are more to do with 1) the direction of the damping - only in a single plane and 2) the complexity of the system given that it's only a single plane of protection vs the 3D protection an appropriate hysteresis rubber might provide and 3) the measurement of 'shock' or impact in 'g's. I couldn't read the graphs well enough in that link. I'll have to have a look at some of my time vg graphs to get my head around it.

Personally, the design is cool. If over complicated....but that's what makes it cool.

 

.. enjoy reading a post of this kind... learning new thing every day... full of joy in our life!

thanks for your well-written post, PF

stefan