The Breitling Watch Source Forums

I recently purchased a 1997 vintage Breitling Old Navitimer II. I have done a bunch of research and it seems they nicknamed this 7750 the Wobbler. I now know what they mean because at times you can feel the rotor make a few revolutions hence the wobble felling. It's weird because I own a Sinn 757 Diapal with the same 7750 in it. I have never felt the wobble on the Sinn. Now I know the 7750 has gone through a few changes over the years. I know the early ones were a 17 Jewel movement and the newer ones being a 25 Jewel movement.

Would anyone know how many Jewels mine may be? I dont know if its possible to know from the year it was made (1997). I do plan on being in Florida next month. I will be stopping down at the Breitling Service Center to have them look at the watch. I will most likely leave it there and have them service it so I know where I am at. I recently picked up a older ladies Rolex datejust at a local watchmaker in my area. I asked him about my Breitling and he said he doesnt work on them due to not being able to get parts and Breitling having so many different case back tools/sizes needed. He did put it on his timing machine and said there is something going on inside thats a little off. (not a straight line) Anyway it seems my watch gains about +14 seconds a day which I want to get closer to zero. When the Chronograph is engaged it is at a -14 seconds a day. Pretty big swing if you ask me. I assume this isn't the normal which leeds me to believe there's a difference in 7750 movements.

Anyway I am kinda thinking (without really knowing) that maybe mine is a older 17 Jewel movement and not as accurate? I will get this confirmed next month for sure. I did also read on some of the older threads here that if it is a older 17 Jewel movement that they can upgrade it to a 25 Jewel movement. Does this mean they rebuild the movement thats in the watch to make it 25 Jewels or do they just replace the movement with a New 25 Jewel movement? I know I will be paying for this and don't really care if it keeps better time. Just curious is all and wonder if anyone else has done this and what the movement upgrade would cost.

TIA, Jim

Whoa, lots and lots of dodgy logic there so let's try and deal with things one at a time......

A jewel is used to reduce friction where otherwise metal parts would be rubbing against one another. There are a number of places in a watch where there is a lot of movement and jewels prevent metal on metal contact. Additionally they act as 'reservoirs' for the oil and help the oil to stay where it's needed. It follows that some places are more important than others and after a while we get to the point of adding jewels for the sake of it because (as you have just proved) the common perception is that more jewels is better.

There is an ISO standard from the 1970s that says that jewel claims can only refer to functional jewels - i.e. jewels that help to reduce friction, but this is still dubious because some places have negligent amounts of friction (or more accurately negligent impact from that friction) in the first place.

In a modern watch you 'need' 17 jewels:

7 jewels in the escapement – two hole jewels and two cap jewels (one each for each end of the balance wheel shaft), two pallet jewels and a roller jewel.
8 hole jewels in the high speed elements of the running train.
2 hole jewels on the centre wheel.

Movements get to 21 jewels when cap jewels are added to the escape wheel and pallet fork - cap jewels prevent vertical movement of the arbor and are of extremely questionable benefit if the movement is well made (there wouldn't be movement).

To get to 23 jewels they are added to the mainspring barrel which is truly laughable as the barrel is rotating 5 or 6 times in 40+ hours, hardly a high friction environment, and jewels 24 and 25 are added to the automatic winding system just because 25 seems like a nicer number than 23.

ETA produce 25 jewel and 17 jewel versions because of the perception of 25 being 'better' and hence a willingness to pay more for it, what is much more relevant to a movement is the grade of the movement. ETA produce all of their movements in three or four grades with the better grades having better finishing, and more importantly better tolerances in production. The highest grade of any movement is called chronometer grade and indicates that the movement is capable of meeting the COSC standards of -4 to +6 seconds per day. That is always the grade that Breitling uses, and since around 2000 they have been going further and actually getting the movement certified by the COSC. You watch is not COSC certified but it is still a chronometer grade movement. No idea whether it is 17 or 25 jewel, but it's truly irrelevant for operation. A 17 jewel movement won't be rebuilt to be a 25, it would be replaced.

Now, as to the behaviour of your watch, +14 seconds per day on a timing machine isn't in itself a particularly helpful number because it's just an average, more relevant would be the behaviours in different positions and how they vary from the +14. That would help to indicate whether the watch needs regulating or whether something else is going on. The -14 with the chronograph engaged is more helpful in that it indicates a significant variance from the behaviour without the chronograph - more significant than you might realise. The chronograph takes power from the running train which reduces the amplitude of the balance, increasing the frequency and resulting in a tendency for the watch to run faster with the chronograph running in some situations. The fact that yours is significantly slower indicates that the chronograph is creating significant friction in the running train and is a strong indicator that the watch needs a service - nothing more.

The Valjoux wobble that is the rotor freewheeling (because it only winds in one direction in the opposite direction it just spins freely) is a well known characteristic, often more prevalent in the higher grade movements because the tighter tolerances mean that it can spin faster, and is nothing to worry about. Ironically, it can be more prevalent in the 25 jewel version because the automatic winding mechanism is jeweled.

Thanks for the quick reply. It definitely clears some things up in my mind. If you remember when I got the watch the Chronograph second hand would keep getting stuck as it approached the 12 o'clock position and with a lite palm nudge to get it going again. The 12 and 6 wheels never advanced either. It was sent back to the seller and his watchmaker fixed it and promptly returned it.

Some of my assumptions have come from the watchmaker I just talked too. He kinda led me to believe that there only so much precision you can get out of a 17 Jewel watch. You know when you assume something right. I guess my assumption is that more Jewels was better but it seems it doesn't really matter that much from what your saying.

I am sure the Service center will get everything dialed in so to speak next month. So when this watch is serviced (I know there's many variables regarding watch position and timing when I get it back) what should I expect the watch to be accuracy wise? Should it fall somewhere in COSC standards of -4/+6? I would be very happy to get to that point.

The issue with your watch is the issue that I warned you about - a non Breitling watchmaker worked on it without access to parts, knowledge, training or tools! If that watchmaker can only do so much with a 17 jewel movement then he isn't much of a watchmaker and I wouldn't let him anywhere near my pieces.

When a watch comes back from service it will have been run through the timing machine at close to +/- 0 in various positions. The problem is that you will then be inconsiderate and instead of leaving it in the box where it can be nice and accurate you are going to do the worst possible thing that you can do for accuracy - you're going to wear it. That will subject it to changing positions, conditions, movement, temperature, etc. constantly and will affect the rate. Some days it will gain, some days it will lose, but on average it will likely be close to the COSC specs, and if not then it is because your behaviour skews it somewhat and that's an easy regulation fix.

Just reread your post and see COSC standards can be met after servicing, Thx.

I bought this Breitling used through a Ebay dealer (watch-u-want). When it showed up the Chronograph didnt work. They had a 90 day guarantee that the watch will work correctly. It was sent back to them on there dime to make right which they did promptly. I bought it used and kinda expect that type of thing and the cost savings was worth the risk to me. I will get it serviced through Breitling the correct way next month so no worries there.

The other wathcmkaer that is local to me worked on my wife's 28 year old Rolex datejust. This watchmaker is certified by AWCI and hes the one that doesnt work on Breitlings for the reasons I stated above. So its 2 different watchmakers here. One I meet and talked with at length and one I never meet that fixed the Chronograph problem on this Breitling. I understand the thought process of not letting someone other than Breitling working on my watch. Especially since you cant get Breitling parts. I assume some people can get away with this because the 7750 movement is a common movement that many watchmakers work on and can get parts for.

I am still learning about automatic watches and now am getting to know how accurate they can be and what I should actually expect out of them. Thanks again for the info.

Breitling takes an ETA movement 'kit' (technically only part of the movement) and then throw some of the parts away to replace them with their own. Some other parts they test to tighter tolerances than ETA and unless they meet those tolerances they too are replaced.

To take generically available ETA parts (likely of lower grades than even ETA supply) and use them in a Breitling is going to have a far more significant impact on the watch than anything else - it's like using cheap Chinese knock off parts in your nice German / Japanese car.

Perception is something we all deal with. I always perceived newer as better as far as watches is concerned especially when buying used. I still do in the way that there potentially isnt as much use on said watch. But you may be buying a watch that has been used every day for 10 years verse a watch that was used very infrequent over say a 20 year period. So I guess if you don't know the direct buyer your always rolling the dice. Once your watch goes through a service interval then you at least know where your at with it.

In the conversation I had with my local watchmaker we got onto the evolution of the Valjoux 7750 because my Breitling has one or at least a variant of one. He told me the older ones were in his opinion better then the new ones. I asked why and he told me the early ones were all machined parts with very good tolerances. He said today they have a lot of stamped out parts and in his opinion were not as good or as well made as the older movements. I guess perception is something we all have based on where we come from and our own experiences. Since he's been working on watches for 40 years I am going to think what he told me is pretty good information.

There may be a big difference between a standard 7750 and what is inside your Navi if there is an ounce of truth in this thread. Sorry to sound so skeptical sharkman, I don't actually mean that. I just think it is a blooming good article.

http://forums.watchuseek.com/f39/how-mu ... 87935.html

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