The Bears' Den--Shirogorov Showcase

So I was missing a couple of bearings in my Neon Ultra-lite. I bought it used, and first time I serviced it the blade was pretty well stuck to the pivot shaft. While trying to dislodge a couple of the bearings got away from me. It ran fine this way, but always bothered me since I knew it wasn't "complete".

I got around to replacing the steel bearings this week with a full set of ceramic bearings. My question is this. As long as I don't over tighten the pivot screw, will the ceramic wear the titanium bearing race any quicker than the steel since they are both harder than titanium?
 
CyberRacer said:
So I was missing a couple of bearings in my Neon Ultra-lite. I bought it used, and first time I serviced it the blade was pretty well stuck to the pivot shaft. While trying to dislodge a couple of the bearings got away from me. It ran fine this way, but always bothered me since I knew it wasn't "complete".

I got around to replacing the steel bearings this week with a full set of ceramic bearings. My question is this. As long as I don't over tighten the pivot screw, will the ceramic wear the titanium bearing race any quicker than the steel since they are both harder than titanium?
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It makes sense that it would. FWIW Shirogorov recommends against installing ceramic bearings in their knives.
 
ChazzyP said:
It makes sense that it would. FWIW Shirogorov recommends against installing ceramic bearings in their knives.
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Welp, then I guess there's another tear down coming in the not to distant future. Appreciate the info.
 
Speaking of taking knives apart, I went ahead and took my F3 apart to get a lanyard on and take a look inside. It appears one of the previous owners was quite fond of grease - I gave the insides a nice clean, lost one of the bearings(as is tradition), re-lubed with some KPL heavy, tied on a lanyard, and closed it up.

Got some replacement bearings coming in sometime this week to replace my single lost bearing, but all things considered I think it went relatively well! Also have my eye on a F3 CD that I'm angling to pick up because of how much I'm enjoying the F3 thus far. Not sure if I'll keep the F3 once the CD comes in, but we shall see!

j3jSoOu.jpg
 
dburpasaurus said:
Looks like spackle 😆 Bet there was a noticeable improvement afterwards!

And +1 to the F3 CD, one of my faves.
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Hilariously the action was actually really dialed in despite the spackling, I suspect the grease itself was good stuff so it didn't impact the action in any way, despite the uhhhh... enthusiastic application.

Post clean with the KPL Heavy in there, almost no difference. Maybe a tiny bit smoother but almost imperceptible.
 
ChazzyP said:
It makes sense that it would. FWIW Shirogorov recommends against installing ceramic bearings in their knives.
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If I remember correctly, Shiro explained why they recommend against using ceramic bearings?
 
CPP said:
If I remember correctly, Shiro explained why they recommend against using ceramic bearings?
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Here's what Tom wrote back in February of 2019:

Sergey has toyed around with the idea of switching to ceramic bearings, but decided against it in the end. As Den said, even heat-treated titanium (and we HT ours) is very soft (indeed in low 40s, though I suspect that differs from ti to ti, as it does from steel to steel) compared to the hardness of ceramic, so there will definitely be abrasion involved, due to ceramic balls slowly eating away at the (relatively) soft ti handles. But there is more to the story. We have looked at a number of suppliers of ceramic balls, and did not find one that would consistently land every single one within our required tolerances. You typically run into one that is ever-so-slightly (and we can be talking microns here) bigger than others. What will happen is that you will crank down on the pivot screw to make sure there is no blade play. Which means this ever-so-slightly-bigger ceramic bearing ball will exert 'extra' pressure on its surroundings, and on one side it comes in contact with the soft titanium. So it starts chewing through that part at an accelerated pace, and eventually makes a dent/track in the titanium. At that point you'd start experiencing light blade wobble when deploying the knife, and the natural reaction would be to tighten down the pivot again just a notch. And then we have that very same slightly bigger ceramic ball starting to chew into ti at an accelerated pace again. Repeat ad nauseam. So the TLDR version is that we have tested ceramic bearings, but decided against them due to the accelerated pace of erosion of titanium handles that come in contact with the ceramic bearing balls, especially as those ones that we have tested were not 100% uniform in size which was a requirement put forth by us.

Of course, since then we have introduced the MRBS which comes with steel underlays. But on my F95 with MRBS (which is a serial one, I did not have one built or tuned just for me) the blade freefalls as soon as I disengage the lockbar. My biggest problem there is getting my fingers out of the way in time. I do realise that we tune each knife by hand, and individual performance would differ from knife to knife, but if you have a broken-in flipper which rides on MRBS, do you really need ceramic ball bearings? Sure, you would need to replace the steel underlays once the ceramic balls would have done their abrasive work, and not the titanium handles. But you can expect accelerated abrasion of the blade, as well. In the end, Sergey decided that the upgrade to ceramic bearing balls would not be enough of a benefit vs the accelerated wearing-out of the pivot system that comes along with it.
 
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Srtr said:
F2Fxsmx.jpg

S7hPQC1.jpg


so far im super impressed with my first shiro.

It wont completely kick my sebenza out of the pocket, especially at work but man its been hard to put this thing down.
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Nice F3 NS bronze! I know what you mean. It’s my favorite knife to date though.
 
It's slightly bigger than what I usually like to carry.

The pants work requires me to wear have terrible pockets so I usually prefer the slim profile of the sebenza.

So far though the f3ns has been really nice.
 
I did this a couple days ago to my old S90V shiro. It had been sitting around in a drawer for years because I didn't like how thick the blade was and how the plunge line area was cut.

1. Cut choil to get rid of plunge line because I hate having it eat into the corners of my stones while sharpening.

2. Thinned the blade down to 3.8 mm, from 4 mm. Thickness behind the edge is now ~0.3mm along the entire length. Final grind is nearly zero ground from spine to edge, with a small microbevel.

3. Acid/stonewashed the blade in 12 M HCl and 30% H2O2

GQl5scR.jpg

DISkIyZ.jpg

rAYyuv2.jpg
 
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Falling behind in my reading but 4-5 pages back there is some discussion about dealing with the loose bearings on re-assembly. Quite a while ago I read a post recommending ceramic tipped tweezers as these are non-magnetic. I bought a pair and highly recommend them. If I loose them I am buying a new pair immediately.
 
Rehn said:
I did this a couple days ago to my old S90V shiro. I had been sitting around in a drawer for years because I didn't like how thick the blade was and how the plunge line area was cut.
1. Cut choil to get rid of plunge line because I having it eat into the corners of my stones while sharpening.
2. Thinned the blade down to 3.8 mm, from 4 mm. Thickness behind the edge is now ~0.3mm along the entire length. Final grind is nearly zero ground from spine to edge, with a small microbevel.
3. Acid/stonewashed the blade in 12 M HCl and 30% H2O2
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That's a lot of work! I'm not an Acid-wash guy myself but definitely see the appeal with the inlay.

Looks good and if it gets the blade back into your pocket, that's what matters!
 
Rehn said:
I did this a couple days ago to my old S90V shiro. I had been sitting around in a drawer for years because I didn't like how thick the blade was and how the plunge line area was cut.

1. Cut choil to get rid of plunge line because I having it eat into the corners of my stones while sharpening.

2. Thinned the blade down to 3.8 mm, from 4 mm. Thickness behind the edge is now ~0.3mm along the entire length. Final grind is nearly zero ground from spine to edge, with a small microbevel.

3. Acid/stonewashed the blade in 12 M HCl and 30% H2O2

GQl5scR.jpg

DISkIyZ.jpg
Click to expand...
I like it! Came out nice!
 
Rehn said:
I did this a couple days ago to my old S90V shiro. It had been sitting around in a drawer for years because I didn't like how thick the blade was and how the plunge line area was cut.

1. Cut choil to get rid of plunge line because I hate having it eat into the corners of my stones while sharpening.

2. Thinned the blade down to 3.8 mm, from 4 mm. Thickness behind the edge is now ~0.3mm along the entire length. Final grind is nearly zero ground from spine to edge, with a small microbevel.

3. Acid/stonewashed the blade in 12 M HCl and 30% H2O2

GQl5scR.jpg

DISkIyZ.jpg

rAYyuv2.jpg
Click to expand...
That's pretty badass work, man.
 
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