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Discussion Starter #1 (Edited)
Hey all,

This thread is NOT meant as a flaming argument, but just another educational thread for me (and whoever else interested).

I never thought much of this paragraph until recent discussions. This is from WatchTime Omega-specific magazine, page 15 (about caliber 8500):

"The organ that's often described as the "motor" or "engine" of a watch movement - the barrel - is doubled in Caliber 8500: two series mounted barrels provide power for at least 60 hours of uninterrupted running. The barrels are "fueled" either manually, by turning the crown, or automatically, by the automatic winding mechanism. Sixty manual rotations of the crown are needed to rotate the barrels 18 times and thus completely "fill the tank." The so-called "hand-wound barrel" without slip clutch is wound first: when fully wound, it amasses a torque of 6,450 micro Newton meters or 3.19 microwatts. Soon afterwards, the winding engergy is also conveyed to the so-called, "automatic barrel" with slipping spring. When fully wound, this barrel accumulates a torque of 6,330 micro Newton meters or 3.13 microwatts.

In the opposite direction, the automatic barrel first discharges its stockpile of energy directly to the center wheel. When its energy supply has become equal to the amount stored in the hand-wound barrel (which occrs in a short time), both "engines" begin simultaneously discharging their remaining store of power. The barrels are coated with DLC (diamond-like carbon), so they work with little loss due to friction and with nearly no wear; a test simulating long-term behavior over a 10-year period showed no traces of premature aging or wear."
 

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Discussion Starter #2 (Edited)
So, a few thoughts from me:

1. Many other manufacturers use double barrels and their power reserve is a lot longer than 60 hours (62 hrs to be exact according Omega). So, why only 60 hrs? i think IWC dual barrels are over 100 hours.

2. Maybe it is just 60 hours because BOTH barrels actually work at the same time most of the time to provide more torque than what one barrel can do. Lets face it, Rolex 3135 has a 50 hour power reserve with just one barrel...so 60 hours with double barrel is just plain pathetic!

3. As noted above, the automatic barrel discharges energy stored first, but as soon as the two barrels become equal in energy, BOTH discharges at the same time from that point on. So, the extra 10 or so hours (over a rolex or 2500 calibers) is probably due to the automatic barrel's initial energy discharge.

4. So, in conclusion, i do NOT think that Omega added the dual barrel system just for the power reserve. As stated above, with dual barrels, the caliber 8500 should have at least 70-100+ hours. I firmly believe now that Omega used the dual barrel system to provide more consistent torque to the coaxial escapement and whatnot.

5. Quote (WT Omega issue page 64-65): "In the newly modified version of the Coaxial escapement (caliber 8500), the 8-leaf co-axial pinion now only performs the single function of providing the propulsive impulse for the balance, the connection to the gear-train occurs with optimally reduced fiction via a pinion with 14-leaves. Essentially, the greater the number of teeth in a pair of gears, the less friction occurs when energy is transferred between them. The goal was to minimize frictional losses throughout the entire gear-train, thus achieving the greatest possible regularity for the torque and energy transfer in interplay with the two barrels."

6. Dual barrel design along with optimization of friction (3-level escapement for example) result in a movement that is accurate/precise and reliable (i hope).

Your thoughts?? Again, for those with more knowledge, please correct anything that i have said.
 

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2. Maybe it is just 60 hours because BOTH barrels actually work at the same time most of the time to provide more torque than what one barrel can do. Lets face it, Rolex 3135 has a 50 hour power reserve with just one barrel...so 60 hours with double barrel is just plain pathetic!
Remember the 3135 runs at 8bps as opposed to 8500's 7bps. So a slower beater design should run even longer in theory.
 

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Discussion Starter #4

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Taking any single aspect of a watch movement and drawing conclusions from it is hard to do as movement design involves all sorts of tradeoffs.

While power reserve and beat frequency can be seen as directly related, power reserve is also related to physical size.

A quick comparison of the physical sizes of the Rolex 3135 and Omega 8500 shows that the Omega movement is thinner 5.5mm vs 6.0mm for the Rolex. The diameter of the Omega is larger at 29.3mm vs 28.5mm for the Rolex, but the Omega ends up being slightly more compact (3%).

Of course total volume of a movement is influenced by other factors too. I'd expect the co-axial escapement and free-sprung balance of the 8500 to take up more space than the traditional lever escapement and balance and finally the winding system, built to minimize vibration and noise likely take more space too. If all these elements take more space, then there is less space for the winding barrels and without some innovation a movement design ends up being larger for a given power reserve.

That's my guess as to why with all the innovation, the Omega 8500 power reserve is not significantly greater.
 

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Discussion Starter #7
Ray...good point...the barrels could be smaller. But, why does both barrels have to work at the same time?? Because they are smaller and that they can't run the movement? Or because higher torque is required??

In other dual barrel systems, do both barrels run at the same time?
 

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Ray...good point...the barrels could be smaller. But, why does both barrels have to work at the same time?? Because they are smaller and that they can't run the movement? Or because higher torque is required??
You would need to research the amount of total torque NM stored in something like a Rolex to compare if the 8500 has higher torque. But if the power consumed is higher, even by Omega's own press suggestion, then you would think this directly equates to higher torque, especially as it's beating slower.
 

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Ray...good point...the barrels could be smaller. But, why does both barrels have to work at the same time?? Because they are smaller and that they can't run the movement? Or because higher torque is required??

In other dual barrel systems, do both barrels run at the same time?
I'd guess that both barrels work at the same time because it is simpler to do it this way. If the barrels were to not deliver power simultaneously a clutch would have to be developed to engage or disengage each barrel.

I'm pretty sure all twin barrel system work this way.

It is also possible that a twin barrel system may actually take more volume than a single barrel system, but the shape of the volume maybe easier to package.
 

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Discussion Starter #11
Have a look at the Eberhard 8 Jours.
Agreed...it makes Omega 60 hrs. reserve look anemic! This is why there must be another alternative for Omega's decision.
 

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Lots and lots of speculation in this post...amazing.

Short of someone truly qualified to make this assesment or Omega themselves comming in here to give us the skinny I think alot of this is just blowing smoke.

Why did they only give the 8500 60 hours power reserve with a dual barrel design?

The old 2500 had about 44 hours or so, and Rolex has 50 or there about, possibly they decided that they only had to best Rolex and not come in with a massive power reserve as most won't care?

Or as someone mentioned above they could have traded off in the desgin elsewhere so that the dual barrel is for reserve but just less than other similar designs which don't have to make such compromises.

Or possibly the way in which they implemented this co axial it does in fact require a bit more power to engage given its larger size...

Who knows...

The fact is that even if they did do this intentionally it does not, nor will it ever translate into what ones perceptions and biases against another movement in the Omega's stable and its supposed "issues" are because you're really talking about two totally different animals here...

On one hand you have a modification of a classic movement that in the time it was designed was built for reliability, low parts count, and smaller size with a modification that adds a cutting edge escapement and balance into the design.

On the other you have a movement built from the ground up that is thicker, larger, and has even more advanced features in it...

So to somehow say the torque provided by the dual barrel design is specifically for one component of an already complex design seems a bit of a reach, unless we get Daniels in here himself or some of the design engineers for Omega/ETA then I fear this is a futile attempt to rationalize something that we cannot comprehend nor fully understand.
 

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Discussion Starter #13 (Edited)
The old 2500 had about 44 hours or so, and Rolex has 50 or there about, possibly they decided that they only had to best Rolex and not come in with a massive power reserve as most won't care?
Huh?! Even if this just one of your "possible" explanations, this is downright ridiculous! :roll: Why would you even think customer won't care about power reserve? If anything, power reserve is one simple concept that most (if not all) watch buyers can appreciate.

Matthew, where in this post did you see me comparing to the 2500's apparent issues?? Have you read YOUR responses in the recent past or the above "explanation"?? Talk about rationalization of something out of thin air! STICK TO TOPIC AT HAND. Re-read my disclaimer above before responding please!

One more thing...if you have no knowledge to add to this discussion, then feel free to bypass this thread.

Thanks...back to topic please.
 

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Here is a PDF with a focus on the 8500 movement, it may or may not be helpfull but worth a look.

HERE

And a focus on the Co-Axial escapement

HERE
 

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Here is a PDF with a focus on the 8500 movement, it may or may not be helpfull but worth a look.

HERE

And a focus on the Co-Axial escapement

HERE
Excellent read, thanks for posting.
 

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Huh?! Even if this just one of your "possible" explanations, this is downright ridiculous! :roll: Why would you even think customer won't care about power reserve? If anything, power reserve is one simple concept that most (if not all) watch buyers can appreciate.

Matthew, where in this post did you see me comparing to the 2500's apparent issues?? Have you read YOUR responses in the recent past or the above "explanation"?? Talk about rationalization of something out of thin air! STICK TO TOPIC AT HAND. Re-read my disclaimer above before responding please!

One more thing...if you have no knowledge to add to this discussion, then feel free to bypass this thread.

Thanks...back to topic please.
The problem with ignore is that you still can see people post back...such a shame.

With that said, Thai...I was trying to be as ridiculous in my presumptions as I find some of them in this and other threads...do I think that Omega only allowed for 60 hours in the 8500 because of that first reason? no.

But I don't think people care about power reserve as you imply they do...I cant even keep count of the number of Rolex owners I have met over the years who still think their watches have five year batteries in them and are clueless about automatic movements.

Also the last bit of your post gave me a good laugh, to think that this thread has absolutely nothing at all to do with the post from before is pretty silly no? I mean here you're essentially trying to further validate an position that is only backed by one other contributor who isn't involved in the watchmaking business.

But if you say that this has nothing to do with that other series of posts on virtually the same or a simlar topic then sure.
 

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Discussion Starter #17
I cant even keep count of the number of Rolex owners I have met over the years who still think their watches have five year batteries in them and are clueless about automatic movements.

But if you say that this has nothing to do with that other series of posts on virtually the same or a simlar topic then sure.
I can't help that you hang around dumb Rolex owners...my father who owns a Rolex has criticized it for having less than spectacular power reserve. He just brought it up at one dinner. He is not a watch maniac, but he knows about the approx. hour reserve. Why? Because he sometimes does not wear it a day or more and would appreciate a longer power reserve. So, yeah, it is important to many people...probably even more so than knowing what movement they have in their watch!

As for your last statement, good, we're in agreement. So, either keep it zip or move on. :-!

Thanks.
 

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I found it odd that the 8500 carried two barrels yet does not display to typical advantages of having an additional barrel.

I suspect it is a torque requirement of the movement, more so given the reduced beat.

Just imagine Omega R&D testing the 8500 for the first time to find it either did not run off one barrel or the power reserve lasting only a little over a day....:-x

Who knows??? A stunning movement either way.

I would like to see an 8 day power reserve manual version of this.......nice.
 

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Have a look at the Eberhard 8 Jours.
I always thought that the 8 day monicker was a gimmick, that it would mean 8 daytimes (ie. 96 hrs of reserve). This post reminded to look harder at this thing. Wow! Truly 192 hrs of power reserve!

How do they do it? This movement features a double barrel mainspring which measures over 5 feet!
 

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I always thought that the 8 day monicker was a gimmick, that it would mean 8 daytimes (ie. 96 hrs of reserve). This post reminded to look harder at this thing. Wow! Truly 192 hrs of power reserve!

How do they do it? This movement features a double barrel mainspring which measures over 5 feet!
Its a bit larger-but not that much-than a typical wrist movement but I have a Cortland/Concord watch Co pocket watch (nothing exceptional and about 42mm) that has an 8 day power reserve and a single winder on a wobble gear with a second barrel that only powers a little hammer that rings a circular wire alarm bell around the inside diameter of the case. I think this was my grandfathers 'traveler' and from the late 20s to mid 30s.

Not sure if this is adding anything useful or not (like maybe its larger size makes a HUGE difference in the size barrel?)-I dont know anything about the '8 jour- wristwatch m4t mentioned. But I do know this old Concord runs accurately for at least 7 days w/o winding
 
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