I don't have any photos to share with you as I wouldn't trade off water resistance for a minutely lighter weight, especially with a classic like that. 🤔

 

If you don't like it, sell it. Don't mod it.
Just my opinion.

 

To me sacrificing some WR to save 1mm makes little sense.

 

It will fit on the wrist better I'll wager.

 

I think that even with the thin caseback the 013 is always going to be a bit chunky and I think that is something most owners like about the watch. It does have a number of unique features for an SKX. I am planning to do a complete service on mine, new 7S mvmt, crystal, crown, gaskets, bezel and a brand new oem jubilee, I have the original full kit from Nov 2003 and I am giving it to my younger son as his Christmas present this year. He has always lusted after it, even though he may not recognize it when finished So many of these get modded I thought it was worthwhile to keep everything completely oem stock.

 

I would leave it stock.

 

Good luck. Not sure if it will be an improvement or not...?

 

WOW!!!

The mighty pros are:
1) Incredible weight reduction... I bet you lose at least 2 grams off the overall weight of the watch with this "mod"
2) $24....? $24!!! ONLY $24 FREAKIN' DOLLARS!!! I mean come on... that's like lunch at Mc D's, or a fancy coffee in Berverly Hills, but instead you get an amazingly thin caseback for a mere $24. Get yours NOW!
3) Reduced water resistance... I mean who wouldn't want to reduce their water resistance by 50%? I understand why they did this and I thank them greatly. This is just to keep more recreational swimmers safe by forcing them to swim in more shallow waters.
4) Shaving a whole 1mm of the thickness... My goodness, who wouldn't want this. My impressed level is through the roof! The possibilities of long sleeve shirts I can wear has now become infinite, as they will ALL fit over the watch now.
5) Thank you Namoki for this, you've definitely changed my life for the better.



In all seriousness, this caseback is useless.

 

I have one the slim casebacks, and tried it on a turtle and SKX, but sorry no pictures. It definitely does make a noticeable difference in how the watch wears. I didn't notice the weight difference and the water resistance doesn't really concern me, especially considering I don't actually put any WR to the test.

 

Thanks, appreciate your insights.

 

Nice find. Didn't know thin caseback existed. It's a screw case back ... some people are reacting as if it's irreversible. Swapping caseback is easier than swapping straps.

would happily give up WR for everyday use, and when i intend to take it diving, ill just put the OEM caseback back on.

 

Opening up the watch and swapping case backs before you go into the water is a great way compromise the water resistance and then flood the watch. Opening up of the caseback should be avoided unless totally necessary for a watch that will be in the water.

 

1mm is not significant at all when you wear a .7" thick Omega Planet Ocean Chronograph. It's .2" thicker than the SKX.

What is an SKX, 13mm thick? 12mm is no different at all. I vote no.

 

1mm is not significant at all when you wear a .7" thick Omega Planet Ocean Chronograph. It's .2" thicker than the SKX.

What is an SKX, 13mm thick? 12mm is no different at all. I vote no.

That’s a good looking watch!

You are correct the skx013 and skx007 are 13mm thick. In my opinion, the skx013 being so compact, makes the proportions not quite right… so I was wondering if that 1mm - for those who have done it can make a difference.

I think bigger watches definitely proportionally pull off 13mm or even thicker without issue. Unfortunately, I’m part of the smaller wrist group, so automatic diver choices are limited.

 

I have the slim caseback and it made a world of a difference on the 5KX. Then again I’m not a diver so there’s that to consider.

 

The reason I sold my Seiko SKX013. Wish I knew about this case back to have tried it out. I don’t mind the top chunky bezel, but not the way it rests on the wrist.

50mm is good enough to swim, just make sure you have a new gasket when changing, and I’d personally recommend same when/if switching to the original case back.

Note the SKX is 200m. The Namiko site says tested actually as far as 60m (though they advert as 50m) and I suspect it probably can stand more.

 

I did a similar mod with a Vostok Scuba Dude. While it did look better when I was looking at it in profile off the wrist, the effect on-wrist was negligible.

It might be different for the SKX013 though depending on how it wears for you. For me the caseback was indeed the primary point of contact, so even 1mm difference would have changed how it wore. Needless to say, I thought this was goofy-looking and I sold it a couple years ago. Seiko has plenty of other divers that wear better.

 

Chill peeps.

I put one of these on a 62mas mod case. The thinner look works with the skin diver vibe. Prolly wouldn’t bother for an SKX though, they got that sweet chonk.

Whatever floats your boat. Don’t dive too far down off said boat tho

 

While on the subject of new gaskets, when installing them it is critical to lubricate them properly or they can get pinched and totally compromise the case integrity. This simple lubricating device is a must have for anyone attempting mods or DIY. I think the other product "Rodico" is a must have as well for anyone who wants to open a watch and do anything. The s-916 is under $20 and the Rodico is under $10, back gaskets 0C3060B0A are cheap insurance at $5.85

 

I just popped on the SKX and it does not sit any bigger on my wrist than any of my other watches such as the Sumo, the SUN023, the SSC017, and certainly not the PO. So, to my eye (and wrist) they all seem pretty much the same which is why I don't see the 1mm making a difference. I realize to others it might but it just seems like such a small decrease in thickness to not be worth the effort in my opinion.

My SKX looks nothing like Chesterworks' photo above and the whole thing, including bracelet, sits pretty flush on my wrist (about 7.25") so there's no gap at all like that picture. I'm not fat (says who?) but my wrist is somewhat flat/wide so most large watches fit well on my arm. The PO is certainly substantial but the lug to lug dimension is still within the width of my wrist so does not look bad at all.

 

The SKX line has 200m WR, not 100. So would the new case back still drop that down to 50m?

 

That 100m could’ve been a reference to the 5KX line.

From the Namoki website:
“…rated to a water resistance of 5ATM. We have tested it ourselves with a 6ATM water pressure tester with no issues whatsoever.”

 

..... So it drops an SKX from 200 down to a 50 rating? Nah thanks.

 

Giving this thread a bump, because Namoki (no affiliation) updated the spec sheet of the slim caseback, they tested and rated it for 100m of water resistance in the meantime, instead of 5 ATM as of the time when this thread was started.
(Especially interesting for SRPE owners like me, since the SRPE is only rated for 100m to begin with.)

 

Giving this thread a bump, because Namoki (no affiliation) updated the spec sheet of the slim caseback, they tested and rated it for 100m of water resistance in the meantime, instead of 5 ATM as of the time when this thread was started.
(Especially interesting for SRPE owners like me, since the SRPE is only rated for 100m to begin with.)

Do they mention the type of rubber gasket used for their test? The SKX has beefier ones than what’s found on the 5KX.

 

In the meantime my slim caseback from Namoki arrived and it was a breeze to "harvest" the gasket from my seethrough SRPE-caseback and transfer it to the slim caseback. Screwed down without a problem and yes, I really like the new slimmer profile of my SRPE67. For the type of water exposure I face in my day to day life I am confident I'll be fine.

 

Did you happen to have pictures of before and after?

 

As an update on this, I ordered the slim CT273 Caseback but found out it will not fit. I need to retrofit in a new spacer or swap in a newer NH36 CT509 movement (where the included spacer will work).

Without a fellow enthusiast comparison photos and experience to go on, I'll park this for now.