Jaeger-LeCoultre

Can some explain to me the technical differences or improvements between the 822 and 976 movements?  For example, the 822 is a well known movement but it's difficult to find information on the 976.  Is one better than the other - ruggedness, accuracy, etc?  I am waiting for a response from JLC but would like to hear your thoughts (especially owners of either the 822 or 976 movements).  Thanks!

Cal 822:
Hand-winding
Pieces number : 134
Vibrations per hour : 21600
Power-reserve : 45 Hours
Jewels : 21
Height : 2.94 mm

Cal 976:
Hand-winding
Pieces number : 151
Vibrations per hour : 28800
Power-reserve : 48 Hours
Jewels : 19
Height : 4.15 mm

Apparently with variable-inertia balance to guarantee enhanced rating stability and a high frequency and with hour hand being able to be independently adjusted.

And I tested a 822 for a long time, I did notice it was pretty accurate.

I don't think the 976, which is much less decorated, does better.

In terms of resistance, I don't see one being more resistant than another.

Yes, the 976 has all what you said, but and yes, on a theorical point, the 976 should be more accurate, but as said, I didn't see the difference, and I didn't read any complaint about the 822.

Best,

Nicolas

PS: The 822 was introduced in 1993, while the 976 came 16 years after, if I remember well.

So, we have some distance in time to be able to judge the 822, we still need more time to see how the 976 behaves.

... it does look prettier than the 976 with the 3/4 plate.

I thought the 822 circa 1993 was derived from a much older JLC movement?

Here is a link to Jerome's fine article upon the launch of the 976, which has some interesting details on the caliber:

jlc.watchprosite.com =

And a scan from the same article:

 

I can't resist adding a scan of the 822 for comparison's sake:

(Photo is by Nicolas, JLC Forum Moderator)

I hope neither Jerome nor Nicolas mind my using their images for this post. 

I have to say, performance issues being equal, the 822 is a much prettier movement to my eyes.  And it is hard to argue with its 20 years of in-the-field testing.

Best,

respo

 

 

Comparing my 976...


...with my 843 which is understandably based on the 822...


With that said, I have to add that my Grande Reverso 976 is the most accurate mechanical watch I have ever owned at only +0.5 or +1 second a day, surpassing all of the more expensive pieces in my small collection. The initial technical merits are clear. What is left to be proven now is the long-term performance: a department where nothing is left to be asked of the older 822.

My new Grande Reverso Calendar does not have a second hand so it is difficult for me to monitor accuracy. However, I asked my AD's watchmaker to put it on a timing machine a few days after receiving the watch and am happy to report out-of-the-box accuracy in the range of +3 to +5 seconds a day, depending on position.

I hope this is not off-topic from what you asked initially, edwyun.

Ruckdee

You must be very happy with both of your Reversos.  The performance of your 976 is impressive.  Without a doubt, two excellent movements by JLC.

Best,

respo

There was no elaborated lighting work involved at all. One was flash bounce off the ceiling and another the wall. I had to take multiple repeats though to get the angle right but it was more labor than skill.

Thanks for looking.

Ruckdee

I had a Reverso squadra with the 977 movement (based on 975 just like the 976) and it was fast maybe 6 seconds a day. Maybe the hand wound version would be more stable since its power is more predictable. The 829 in my Reverso Gran Sport chrono then again is insanely accurate at +0.5/+1.0 a day even though it's not technically engineered for accuracy in the same way as the autotractors.

With more real life samples like yours and mine, I'm sure the picture will be even more complete.

Ruckdee

the calibre 970 family in auto or manual wind is a special reverso movement that has the SPYR gear train that has a more rounded profile of the wheel teeth giving  optimal torque efficiency-better than the standard NIHS profile.the flat balance spring is made in collaboration with A LANGE AND SOHNE and is laser welded .the variable inertia glucydur balance wheel(no regulator just poising weights) also has a moment of inertia of 14mg/cm2 as against a calibre 899 of 3.8mg/cm2,this balance wheel sits on a bridge as against a cock for greater stability for the larger diameter balance wheel whizzing around at 28800 vph(4hz) and power reserve of 48hrs.

the master tourbillon with the calbre 978 auto in 2009 won 1st prize in the chronometre timing competition from the geneva observatory.

second prize went to the reverso gyrotorbillon 2!!

so as you can see for the calibre 976 in manual form in the  grand reverso is a 'little beauty' and should not be judged by looks alone and is in the chronometre class and in my humble opinion would be even better with a silicon escapement and  and balance spring.    

yes i do own reverso's- with a calibre 976 and 859(822 with chronograph) and with 875. i do not like automatics.manual wind rules!!

hope this of interest

regards paul

Of course you are right. The 976 should not be judged on its look.

But it would have been even better if JLC would have spend a bit more of time in the decoration, the finish on this movement, don't you think?

Thanks, once again, for your very interesting answer.

Best,

Nicolas

 

hi nicolas

the decoration so called on the plates-perlage,geneva stripes etc is their for a purpose of trapping some of the microscopic dust particules.

depending on what other decoration/pleaseing to the eye is used will not inprove its performance- the whole idea of the watch is to display the time as accuratly as possible.

for me the decoration is not that important as to the quality of the mechanical parts that go to make up the movement. i would rather the time was spent to getting the cased up watch to run in all 9 positions to observatory standard of the highest order and the boundaries of accuracy pushed to there limits.

if the caseback was not glass and movements visable you would not be able to see the finish/skeletonised to compare-of cause a high standard of finish is very important to a limit but not the be and end all.if the movement is of good quality then automatically the finish will be also.

i must also get to one of my other bug bares-tourbillons which were invented by A L BREGUET for the pocket watch that sits pendant up mostly

in the breast pocket.today they are fitted to almost all ranges of wristwatch and are more of a gimmick-but not all of cause some well made ones are very good - but most are  just for show and to multiply the cost by 5 to 10 time the standard watch price without the tourbillon-but look good .the average wrist movement should compensate for positional deviations. to some degree.

so nicolas i am at the other end of the spectrum to you on decoration-for me its supreme quality, plain, and accuracy at its limits- with solid caseback.

regards paul

 

Cal 162:

 

 

 

Or Cal 171:

 

 

Or... Cal 170?

 

 

 

3 great Chronometer movements whch gather beauty and accuracy... To elaborate my point.

I could also mention the Cal 488, which is also a nice Chronometre movement, housed in the JLC Mark 11.

But I agree with you, beauty without accuracy or efficiency is nothing... Of interest.

Best,

Nicolas

hi nicolas

nice photo' of some rare calibres from the 40-50's-cal 170 for instance one of those very good tourbillions i was talking about-so good that  only 26 were ever made for this pocket watch calibre.

i was on about todays production-calibres of yester years were made/sprung('springers) better than today.you only have to see the sales price at ANTIQURUM

the mk11 or geophysic with cal p478/Bw/Str is undoubtably a brillant execution of the watchmaking art and very accurate if serviced correctly-simple-clean and no glass back!

what would you have-1940-50 wrist watch from the high end mass produced makers or 2000-2010 wristwatch from high end mass produced maker?

 paul

Thry don't take the time to do these masterpeices anymore.

I am not sure I understand your question, but if your point is to ask if I like sapphire case back, I am not a big fan of them.

I prefer to play with my solid case back when I want to have an eye on the movement.

As for your second question, I thinik the golden era of watchmaking was somewhere around the Fifties...

Best,

Nicolas

 

 

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Thanks.  Your real world experience with these watches definitely helps.