Sebenza 31 Lock Rock?!

Basically...you can hold your sebenza in your hand open with the spine toward your palm...push down on the lockbar itself with your thumb. Push toward the pivot...the lockbar will move, and then spring back when the pressure is let off. I noticed this years ago, and it hasnt been a real world issue so far. :)
Seems it moves more on the Zaan and definitely on the 31.
 
johnnytoxin said:
If the vertical movement is due to the lock slipping toward the unlocked position, then hell no it’s not ok. If the movement is due to the lock bar flexing toward the spine I believe it’s a inherently negative feature of all liner and frame locks. However, Some may require more force than others to induce the flex.
Click to expand...

I've been going back and forth with this since I received the knife. Should I keep a knife that moves this much?

a little I would be ok with.
 
I just tried this on three large 21s. With the blade opened and knife sitting on my kitchen counter. Take one hand and hold down on the handle and take my other hand and push down on the blade. Moved on all three of them. Haven’t tried any of my Inkosi’s or more 21s. Those three were laying around. As johnnytoxin johnnytoxin said it means nothing in real world use. With my insingo I use the swedge to scrape with at times. Thats really the only time I put pressure on the spine. I’ve never noticed the flex while using
 
Dcdavis said:
I just tried this on three large 21s. With the blade opened and knife sitting on my kitchen counter. Take one hand and hold down on the handle and take my other hand and push down on the blade. Moved on all three of them. Haven’t tried any of my Inkosi’s or more 21s. Those three were laying around. As johnnytoxin johnnytoxin said it means nothing in real world use. With my insingo I use the swedge to scrape with at times. Thats really the only time I put pressure on the spine. I’ve never noticed the flex while using
Click to expand...

how much move did they have?
 
Just for the heck of it, I tried the “flex test” on both a Spyderco manix 2 and a cold steel air lite. The ball bearing lock moved a bit, so did the triad. Obviously the flex in these locks is from something else since these are different mechanisms. I simply wanted to prove that you can find “movement” in any lock mechanism if you try hard enough. The only thing 100% flex free is a fixed blade.

But I do agree with most here, the 31 seems to flex too easily.
 
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Ptman2000 said:
how much move did they have?
Click to expand...
https://imgur.com/gallery/1SnLcCJ
there’s a link to a video. I’ve used these knives for years and never had any issues with the locks. I work with CRKs everyday and even after finding this I’ll put it back in my pocket tomorrow and use it with no hesitation. If your using a folding knife for what it’s intended for I see no problem. Also after years of knife usage I’ve never noticed this flex
 
Dcdavis said:
https://imgur.com/gallery/1SnLcCJ
there’s a link to a video. I’ve used these knives for years and never had any issues with the locks. I work with CRKs everyday and even after finding this I’ll put it back in my pocket tomorrow and use it with no hesitation. If your using a folding knife for what it’s intended for I see no problem. Also after years of knife usage I’ve never noticed this flex
Click to expand...

That is a great video showing exactly what I found. You can zoom in and see the lock bar flexing toward the spine. Thanks for posting that DC!
 
So it's settled then. The flex exists on the 21 as well, and no one's had a 21 close on their hand from normal use. Maybe the 31 deserves a few more months to prove itself?
 
aVyD said:
So it's settled then. The flex exists on the 21 as well, and no one's had a 21 close on their hand from normal use. Maybe the 31 deserves a few more months to prove itself?
Click to expand...

whew....thankful I have the only 21’s without flex....lol ebay here I come....lol
 
nyefmaker said:
I just tried that on about a 1/2 dozen large 21 sebenzas I have laying around and none of them moved in the slightest. I no longer own any Zaans so will reserve my opinion on their locks.
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Same here on my two small 21's. However when the lock is disengaged I can move the lockbar pretty easily towards the stop pin, but when locked it's solid.

Off course I can induse flex if enough force is applied, but the lock geometry makes it very hard to do.
 
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i don´t regard the frame/liner mechanism as a "lock". In a picture: it does not lock the door like a key does. It locks like a wedge or chock does. I treat all of my sebenzas and inkosis as sturdy slip joints. in my opinion sebenzas are "framespring to bladetang slip joints". This mechanism is masterfully and elegantly implemented in the sebenza 21. Time will tell, if the 31 is a step backwards or progress. I decided to wait at least year with purchases. I don't want to be the beta tester for the company.
 
We need that intrepid Umnumzaan collector to post a pic of the prototype Umnum that had two ceramic balls. One for the lock/detent, and one to prevent lock bar flex. Clearly Chris Reeve himself detected this flexing in the Umnumzaan design, found a way to prevent it on the Umnumzaan prototype, and then abandoned the idea as unnecessary or of very low benefit.

I gave up on trying to post photos to this site, so maybe someone who has one of these extremely rare knives (lucky) or can find a link could share a photos of the two-ball lockbars of the very early Umnum’s
 
Here’s a post about the “two-ball Umnumzaan” prototype with the “anti-lock-rock” ball. It has a Flickr folder with pics. Chris Reeve left the idea in the dust. Maybe we should arrive at the same conclusion with the 31, that the “problem” is not a problem worth the complexity of the solution?

https://www.bladeforums.com/threads/chris-reeve-umnumzaan-prototype-1-20.1120988/

I will be buying a 31, barring the collapse of society.
 
johnnytoxin said:
I’m probably gonna ruin some people’s day with this: I tried mimicking what the guy did in the video with these 3 knives.
TzPHjBm.jpg

All of them flexed like on the video. The Sebenza 21 and the Rat 1 moved slightly less than the Zaan though. Pushing on the blade in the direction of the yellow arrow forces the lock bar to flex in the direction of the black arrow. It appears normal liner and frame locks will do this as well.
jLiNsAf.jpg
Click to expand...

So far I never tested by pressing the handle against a table. Doing it this way, I can indeed detect flex on all of my framelocks, and also some liner locks.

Knives tested, all with moderate pressure on the spine:

Not flexing, but slipping towards unlocked: Spydiechef

Moderate flexing, but no slipping towards unlocked: Large Inkosi, Small Sebenza, Small Inkosi, XM-18 3" Skinny Liner Lock, XM-18 3,5" Skinny

Small amount of flexing, no slipping: Shirogorov Neon Zero and F95R (liner lock), Case Tribal Spear (mid lock)

No flexing: Spyderco Military, Para 3, Native 5
 
kidcongo said:
Here’s a post about the “two-ball Umnumzaan” prototype with the “anti-lock-rock” ball. It has a Flickr folder with pics. Chris Reeve left the idea in the dust. Maybe we should arrive at the same conclusion with the 31, that the “problem” is not a problem worth the complexity of the solution?

https://www.bladeforums.com/threads/chris-reeve-umnumzaan-prototype-1-20.1120988/

I will be buying a 31, barring the collapse of society.
Click to expand...
I agree. I don’t see it as a problem. I’ve never noticed it over the years with normal usage. I have no intention of cancelling my 31 lefty order and have my micarta 21 with me today using it without doubting it one bit
 
Happy to get everyone’s opinions and all the tests! That’s great!

the 31 has been very smooth and feels great with the single piece micarta.

it’s strange that this has only come to light with the 31’s but has been there in the background for a while it seems.
 
Hasn't it already been tweeked out by Chris Reeve for the Umnumzaan design or does the current Zaan have it too?
 
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