Home Page  |  Page Map|


Naked Sumo

Gottcha... :)

Actually, I just decided to take a peak inside my Sumo and why all the rave about the 6R15... I have to say I'm left very impress with the work done by Seiko for a $400 watch. The Sumo actually runs a 6R15B (I wonder whats the diffence to the 6R15A found on the Alpinist and Spirits models)

Not being a technical buff, I'll just let the pictures do the talking and welcome any experts to add comments to the design and specs...

Now here's the watch porn promised...

Tintin with Seiko founder Kintaro Hattori
"Do you have any non-Fair-Trade coffee? I prefer to taste the exploitation." -- Mary (speaking to barista at Starbucks)
Thanks for sharing! :) If you find yourself alone, riding through green fields with the sun on your face, do not be troubled, for you are in Elysium, and are already dead. MDM
Kind of wish they did the stripes on the top plates as well, but for $400 I can't really complain about that, particularly given that it's not a display back.

As to the difference between 6R15A and B, here's what I found:

6R15B uses 6 different parts compared to the 6R15A. The 6 parts are all from the new 6R20 movement used in the Premier range. Seiko decided to do this to achieve economies of scale through mainstreaming the parts for the production of both watches.

There is no quality difference between the two movements, this is merely a cost cutting exercise.

The different parts are; the barrel and train wheel bridge, the movement barrel (complete), the centre wheel & pinion, the ratchet wheel, the oscillating weight and the ratchet wheel screw.

This is by Seiya-Kobayashi.

For the original post...well, it's from another forum and the software just won't let me insert that link. Google it.

But c'mon TZ - why the heck can't we link to another forum for an intelligent discussion? And this is called a global community? A pretty isolated one, if you ask me.[/rant]
It's good to see the movement filling out the case so well. This watch is definitely going to be a best-seller.
thanks for those info BTB... much appreciated. if the 6R15B are using parts from the 6R20 (another step up for the premier models?), then its an improvement over the 6R15A wouldn't you say? Tintin with Seiko founder Kintaro Hattori
and the in-house production... especially for the Sumo seeing it is one of the first model to use the 6R15B.. the movement is specifically designed to fit its watches...

i also opened up a Swiss yesterday that cost 3 times more and it wasn't as impressive as the Sumo for the simple fact that the case and movement was just ill-matched.. Tintin with Seiko founder Kintaro Hattori
Hi tintin,

Kind of hard to say if it's an improvement over the A-version or not in terms of movement quality, because it's hard to quantify 'quality' in this case. We don't really know if the shared parts are better finished for more accurate performance (less friction/drag, etc.), or if they look any better and so on. I don't personally view the Premier line as any more high-end than the SBDC's. I think the main reason Premiers are more expensive (and thus perceived as a more upscale model) is due to the added functions like Power Reserve and separate day/date displays. I've never handled one, so I don't know if the fit/finish is better than on Sumos, but just based on the looks, I'd really take a Sumo over a Premier any day.
nice pics. =) i'm still not convinced i like it enough to buy one, but they do look nice.

<* shark >>><
... new Spirits also carry the 6R15B movement ... I own a SCVS003 (with display back) and that is the movement it carries ... bought it a month ago ...

Have a nice day and enjoy the Sumo, I happen to own the orange dial version too, just to difficult not to buy this Seikos while living here in Japan ;) ...

Thanks, sort of. Don't count every hour in the day, make every hour in the day count
I don't know about 6R15A or B, but I can say that no one should be disappointed with the performance of the SBDC. Mine is consistently running about -2 sec/day on the wrist, and +4 off-wrist. So I can keep it running betwen +/- about 2 sec/day just by normal wear (on-wrist during the day, off-wrist over night).