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7s26b performance update

Just wanted to follow-up on an earlier email since i've now had my new Seiko 5 with the 'b' version of the 7s26 movement for a couple of weeks now. And there were a number of people who were interested in the performance because there was speculation that the overall performance had been somewhat improved by a new balance or regulator mechanism or something.

Unfortunately, I have not experienced any improvement in performance over the 'a' versions of this movement that I own. Out-of-the-box I was hoping (based upon anecdotal evidence) for better than the standard +10-20 seconds per day that most 'a' versions exhibit. But mine was right in that 10-20 seconds per day range (probably around +16).

So I opened the case and moved the regulator arm just a bit and observed the watch for a couple more days. I was lucky and I think I moved it just right. On the wrist the watch keeps near-perfect time. Of course, I have also had the same experience with my 'a' version watches that I have regulated myself.

I was hoping then that the supposed improvements that were made might result in a better stabilty of rate and less positional variance (i.e. the deviation between different positions the watch is left to rest in wouldn't be very large). But the watch actually does gain or lose quite a few seconds depending upon whether you rest it face down, on it's side or on it's back. I did not check this regularly enough to have any real date. I just know that when I put it down at night, it's always at least couple seconds fast or slow and often more, depending upon the exact position.

So, in sum, based upon my own watch I don't see any improvements. It could just be my example. Several people have reported better out-of-the-box regulation and better positional variance. But not so in my case. I still love the watch though and it's plenty accurate for my purposes.

here's a pic courtesy of the seller:

There are only 10 types of people in the world - those who understand binary and those who don't
Answer:
Interesting post, thanks for sharing. I'm one of the people who's experienced very good out-of-box timekeeping on the 7S26B. I didn't make any notes of positional variance but when worn regularly and resting on the caseback my BFS was keeping COSC time from the moment I got it. Maybe I'm just lucky...

Love the dial on that 5, by the way! Seikos: 6R20 Premier Automatic, white-dialled BFS, SKX007. Others: Omega Geneve cal. 601, a couple of old quartz watches. My blog: http://clockworktechnology.blogspot.com/
Answer:
I'm not too surprised about the positional variance. From what I have seen in WatchTime magazine, some really expensive watches have it, so we can't complain if a Seiko 5 does too. I have the same watch you have but in blue, and I think it looks pretty good.
Answer:
There are only 10 types of people in the world - those who understand binary and those who don't
Answer:
The blue dial version is the SNX805, which has the same case, but the dial is slightly different since it has the 1-12 hour numbers, and then smaller 13-24.
Answer:
FYI, the 7S35 movement in my nearly two month old SNM035 Auto Diver runs at between 12 and 14 seconds plus/day, on the wrist (24/7 and I'm an active individual).

It's unfortunate that movements capable of better performance don't deliver accordingly out of the box, and that understandable owner regulation compromises water-tightness and likely voids the warranty.

If Seiko tried a little harder (better regulation), they could be on to something with their nicely made, aesthetically endearing, and affordable mechanical automatics.

I also own a Tissot PR50 Automatic (ETA2824) that runs at <= 1 sec/day, as delivered. It is "Swiss Made" in 316L stainless and has a sapphire crystal and sells for less than USD300. By contrast, new Seiko5 autos showing up at some local retailers appear to have a mix of Asian origin components and have MSRPs in the USD325 range with mineral crystals. Seems to me that Seiko could afford to regulate the watches more carefully.
Answer:
I am not impressed with reported performance of most Swiss in-house, "manufacture" movements but if that's your thing Seiko isn't far off the their mark.

It's getting harder to touch ETA and Rolex however...
Answer:
Hope Seiko continues to give ever increasing priority to accurate timekeeping, even at the lower price points. Intuitively, I suspect that it's within their realm of possibility. If (and, I mean no disrespect) the desire is there. With accuracy in hand, their product diversity would be (...even...) more enticing.

In the meantime, I'll be looking forward to the next opportunity to sample a Grand Seiko. :)
Answer:
For about the same price as your Tissot you could get a Seiko Spirit with the 6R15 movement, and that would be a better comparison than a Seiko 5. The Spirits are outstanding watches for the money.
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The Spirit is a Japan-only model, but I have sent you a PM with a couple of vendors.
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While I'm familiar with the vendors that you've mentioned (thank you), I, like many others, am looking forward to when Seiko itself makes its more desirable pieces available in the States.
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I guess the decision reason behind the B version is simply to cut cost. We are all boys before watches.
Answer:
Unfortunately, short of putting it on a timing machine, there's no really good way of doing a truly meaningful position variation test on a 7S26 movement because it has no manual wind option, therefore there is no way to tell, for an overnight test, what the state of wind was when it was set down. The state of wind will always have an effect on the rate (isochronism). So for any kind of overnight testing that would be a control wildcard. If you put it on a machine and run it through the positional tests for over, say, an hour, and then re-test the original position to see if there is any rate change from the mainspring being run down for an hour, it will give you a reasonable view of your positional variations for that "window" of wind.

My own 7S26A tested out on the machine with a maximum rate variation of about 10 seconds for 6 positions, tested this way. Not COSC, but easily on a par with my other three ETA 2824-2's

For what it's worth, if it's a daily wearer, most automatics will be fully wound all the time, except perhaps when you first get up in the morning.

Dave
Answer:
Hi all,
I agree the Spirits not only come with better 6R15 movement, the build and finish of the case & bracelet are of much higher quality than cheaper models.