Jaeger-LeCoultre Grande Tradition Tourbillon Perpetual Calendar

You've possibly noticed that I've been really appealed by the new Grande Reverso at the just finished SIHH. In fact another "Grande" appealed to me (I could add that many other "grandes" appealed to me and Nicolas during this SIHH, but that's not the subject of this forum   ).

The subject of this text is my favourite choice in the new Grande Tradition range. Apart the minute repeater with regulator dial, the other option is a Tourbillon watch with perpetual calendar. Surprisingly this watch is presented (at least in the press kit) as a premiere in terms of combination of complications for Jaeger-LeCoultre but if I dare remember the Gyrotourbillon 1 was already a Tourbillon with a perpetual calendar. Let's say this Grande Tradition is the first JLC watch with "only" a Tourbillon and perpetual calendar.

Jaeger-LeCoultre Grande Tradition Tourbillon with perpetual calendar in pink gold

So technically this new Grande Tradition is indeed a Master Tourbillon calibre with an added obviously in-house perpetual calendar. But that's not just that!

You can see below that on the tourbillon part the first improvement is a new and much nicer design of the upper tourbillon carriage bridge. This rounded bridge is very beautifully finished and polished. This more classical design will certainly help convince that a more reasonably priced tourbillon watch can still be very beautifully finished, hopefully even those that so far have not accepted to see JLC as a top finish watchmaker!!

The new toubillon carriage upper bridge

Out of this new bridge design, the tourbillon is identical to the one of the Master Tourbillon calibre, except for one other exception strictly reserved to the yellow gold limited edition. This edition limited to 300 pieces adopts a new silicon lever and lever wheel. Silicon made its debut in a Jaeger-LeCoultre watch nearly two years ago in the extraordinary Master Compressor Extreme Lab, the first ever watch without any lubrification.

New silicon lever and lever wheel in a prototype calibre

If the lever wheel looks close to the lever wheel of the Extreme lab, the lever is quite different. The traditional Extreme Lab lever was fitted with black diamond pallets, while the new lever is made single-block in silicon, i.e. the pallets are integrated by construction in the design.

The blue lever wheel

The two silicon parts are covered with a diamond coating. The diamond nanocrystals are coated and then plasma polished to bring a smooth and hard surface. The resistance to wear and friction coefficient are consequently equivalent to half those of silicon oxide.

In fact a layer of silicon oxide is usually used to protect the surface of silicon parts from the formation of fissures when the parts are handled. But in the use of two silicon parts working together, friction and the wear of silicon oxide (SiO2) on silicon oxide are so bad that they cancel all the interest of using silicon parts. They are in fact lower than those achieved by classic lubricated materials. That's why JLC replaced silicon oxide by a diamond coating. Diamond coating is also more efficient to prevent fissures.

The new silicon lever wheel

With these new silicon lever and lever wheel the inertia of the components is divided by three. The silicon construction also allows a much better dimensional precision.

Again the losses due to friction are much reduced, achieving a friction coefficient of 0.08 between diamond and diamond against 0.13 between steel and ruby with the traditional escapement found in the Master Tourbillon and the pink gold and platinum Grande Tradition (and 0.16 in a silicon oxide on silicon oxide combination).

The new silicon lever

Obviously these silicon parts have to bring an advantage that must be measurable! That's not an innovation for the sake of it.

So precision of the watch must be improved. As a result Jaeger-LeCoultre has elevated its 1000 Hours label to another level, "1000 Hours Chrono". So far this series of test consisted in tests about water resistance, shock resistance, power reserve, smooth operation and last but not least precision. Specially for the silicon "escaped" Grande Tradition models the 1000 Hours tests will be complemented by new high precision tests on the model of the COSC tests but on finished watches and not just assembled calibres.

In the standard 1000 Hours tests, watches are allowed to deviate from -1 to +6 sec per day in any position. In the 1000 Hours Chrono tests, watches will be allowed to deviate from -1 to +4 sec per day in any position.

The silicon escapement fitted calibre prototype

So after the Master Tourbillon in 2006, The Extreme Lab in 2007, the Amvox3 in 2008, the Grande Tradition Tourbillon with perpetual calendar is the fourth version of this very reliable, more and more and very precise,  upper finished calibre.

Back side of calibre 987

This 8.15mm thick calibre houses 403 parts (only 401 in the silicon "escaped" version, the two jewels of the lever being integrated in the lever). The calibre is housed in a 42mm case.

The limited yellow gold silicon escaped version adds a built-in magnifying glass in the back to allow a better view on the silicon parts.

The pink gold Grande Tradition

The other aspect of this watch on the technical side is its perpetual calendar function. You will notice the thinness of the calendar plate that seems nearly melted on top of the calibre above the tourbillon.

The perpetual calendar

The perpetual calendar is quite complete, in the JLC way. It is also the return of an automatic perpetual calendar in the JLC range.

Tourbillon perpetuel sounds like a prophetic promise

Positioned as a watch respecting the greatest traditions, the Grande Tradition shows a two parts dial. The main part is a near pocket watch like sober and very clean three quarter upper dial with applied indexes already seen in the Grande Ultra Thin last year.

The lower part is reserved to enhance the tourbillon device, with a more mechanical look and finish, being in fact part of the calibre itself, and calling back the Gyrotourbillon 2 extraordinary finish seen last year! The best of both worlds? I think so!

A new case

The case is new, close to the new case seen last year with the new Master Hometime, with just a more rounded bezel.

The platinum version

So you've understood. I'm still not finished with last year's impressive choice of new watches from Jaeger-LeCoultre and already a few more sublime pieces are coming like this Grande Tradition. There are perhaps less new pieces I'd like to own this year, but these are big fishes that complement perfectly the offerings of last year.

We can also see how JLC melts more and more finely the most subtle evolutions of cases, indexes, finishes,….

The future is bright for Jaeger-LeCoultre if we watch lovers can see and admit those improvements. Jaeger-LeCoultre watches have seemingly never been better than today and pay the best homage to the beauties of the past.

Dje