Sebenza 21 lock problem

Do you consider my knife to have an issue at all?

  • Yes

    Votes: 9 33.3%

  • No

    Votes: 18 66.7%
  • Total voters
    27
Sergeua

Sergeua

Joined
May 1, 2016
Messages
1,745
Hello everyone

I noticed something with my large sebenza 21 after the recent thread on 31's lock rock and wanted to get some of your opinions without muddying up that thread.
I bought two sebenzas from authorized dealer (Cutting Edge Cutlery). Large and small 21. Visually the lock geometries looked similar to me. Looked up a few online pictures and a lot of them look just like mine. These two and maybe looking at few more in store is my only exposure to CRK products.

I only tested the large ( the only crk I have currently ) . These are Jan 2017 models.
No battoning / spine whacking was previously done with this knife or any kind of hard use other than cutting cardboard. This knife doesn't have any other problems, it's perfectly centered, it's been reassembled a few times and went back together perfect every time. The lockup has stayed the same throughout 2+ years.

Issue is simple, the lock fails in my opinion. I would like to know if this is a problem with just my sebenza or it's more widespread. Some might not even consider this to be a problem. Opinions welcome.

I am attaching a few videos with brief explanations. Thank you.


(Lock up here is same be it slow or harder opening. A small bevel at the very edge of the *edited*lockface* is a detent ramp I believe . It doesn't help that that piece of lockbar is missing in my opinion)


(Here you can see the detent ramp at work and the problem I am showing is the lockbar is slipping at very end)

Wanted to do it justice so I took the knife apart to get rid of all greese/lube and also show you all the condition of internals.

(looks prone to slip by design to me, but I don't have much data to conclude this)

(reassembled back with no lube now)

I have full drawer of knives that all been tested in the same manner and they don't exhibit any of this. I like my sebenza, it's a very thought through knife, with a lot of features I discovered for myself using it and it saddens me the knife is doing this. It is not okay in my book.
 
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Are the issues at question that the lock will fail when you put enough pressure on the spine? Also the blade will fold when you take pressure off of the lockbar and release it a little?
 
Dcdavis said:
Are the issues at question that the lock will fail when you put enough pressure on the spine? Also the blade will fold when you take pressure off of the lockbar and release it a little?
Click to expand...
To me there is an issue that the knife folds with a bit of pressure on the spine, just with my fingers.
I try to dig deeper into why it is doing it on a pretty much new knife and the findings bother me. I consider it not to be safe and view it as a design flaw or perhaps just a problem with my sebenza only. If it is my knife only, I would like to seek a replacement. If it is designed this way... I'd like to hear what you guys think.
I think it's important for it to be brought to attention. Maybe I am a little late to the party but still.
 
1st video: Cold steel showed us the 21 will fail with less than 500lbs. I think you were pushing hard enough that lock slipping is justified. I heard that grunt/exhale sound people make when exerting force when it popped. I personally have (thanks to the 31 thread) pushed on my two dozen 21's as hard as I feel I should, no failures. As Davis said, enough force makes everything fail.

2nd. video: ??? Um, that's the detent ball hitting on the end of the lock. Why are you playing with it like that? The 21 is famous or maybe loved for the double click sound when opening. This is VERY normal, did you only notice this feature after prolonged ownership? All that scraping of the lock bar edge on the blade is wearing away the very edge.

3rd video: I think you are seeing mild wear from obsessive locking jiggling and forcing it to fail. You captioned it "prone to slip by design" but admit "not having data to support it". Don't post personal feelings as facts on public forums. While you have free speech, it's best to not abuse those rights.

4th video: You again push the lock over and hold the blade (0:21) to force the knife in a partially failed position. You then push hard on the blade and it fails. What are you trying to show???? "It's so hard, but there it is" at (0:30) in the video. Even when this guy is TRYING to make it fail, it's still hard to do...

Keep it up man, that lock can tolerate mild abuse... but you're really giving that knife hell. You have way too many posts not to know about all this. Why are you trying to make the 21 look bad? Is this damage control for the 56 page "31 lock rock" thread?

"I think it's important for it to be brought to attention. Maybe I am a little late to the party but still." After twelve years, the 21 has finally been exposed as a total failure, perhaps even by design. :rolleyes:
 
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Honed_Edge said:
1st video: Cold steel showed us the 21 will fail with less than 500lbs. I think you were pushing hard enough that lock slipping is justified. I heard that grunt/exhale sound people make when exerting force when it popped. I personally have (thanks to the 31 thread) pushed on my two dozen 21's as hard as I feel I should, no failures. As Davis said, enough force makes everything fail.

2nd. video: ??? Um, that's the detent ball hitting on the end of the lock. Why are you playing with it like that? The 21 is famous or maybe loved for the double click sound when opening. This is VERY normal, did you only notice this feature after prolonged ownership? All that scraping of the lock bar edge on the blade is wearing away the very edge.

3rd video: I think you are seeing mild wear from obsessive locking jiggling and forcing it to fail. You captioned it "prone to slip by design" but admit "not having data to support it". Don't post personal feelings as facts on public forums. While you have free speech, it's best to not abuse those rights.

4th video: You again push the lock over and hold the blade (0:21) to force the knife in a partially failed position. You then push hard on the blade and it fails. What are you trying to show???? "It's so hard, but there it is" at (0:30) in the video. Even when this guy is TRYING to make it fail, it's still hard to do...

Keep it up man, that lock can tolerate mild abuse... but you're really giving that knife hell. You have way too many posts not to know about all this. Why are you trying to make the 21 look bad? Is this damage control for the 56 page "31 lock rock" thread?

"I think it's important for it to be brought to attention. Maybe I am a little late to the party but still." After twelve years, the 21 has finally been exposed as a total failure, perhaps even by design. :rolleyes:
Click to expand...
Only going to address some of your questions. Maybe it clarifies for others also.
The lock on my 21 wouldn't be failing so easily if at close to the very end it wouldn't slip. I move the lockbar to the end (or beginning of lockface) to show you why it fails on mine. It is prone to slip. I don't think I damaged anything. Let's look inside of yours and compare.
I believe a proper lock shouldn't be doing it. I'm asking for input to see if there is a problem with mine or . Cold steel did their own test and didn't show you the intricacies I'm pointing out, they got nothing to do with my observations. I'm not whacking the spine here. Also, I don't even weight 200 lbs.
 
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I am in Canada and I don't want to deal with Canadian border authorities in the near future.
Before I contact CRK it's interesting to know what you guys think about my findings. I haven't seen anybody else bring these forward before.
H Honed_Edge I have a bit of a headache, I am wearing mask all day and waiting for my covid test to come back. It's a bit hard to have to explain myself.
Been working through this whole lockdown and now that I am unwell, finally have some time to post something.
If a picture worth a 1000 words, I thought videos would be pretty explanatory. There are no tricks or obsessive wear like you think. Also, don't tell me what to do.
When I felt better I folded the knife with my hands without moving the lock bar at all. I don't want anyone to try that and don't want to reproduce it myself.
I feel the videos I took show what I am talking about clearly.
Dcdavis Dcdavis sorry I didn't understand your second question.
 
I’m hesitant to call it normal, but it did seem as though you really had to put some force into it on the first video, and after you flexed the lockbar a few times without a full close/open cycle. The lockbar probably isn’t designed to be a shock absorber.

When I was 8 my Cub Master taught me to treat all folders like slip joints, because all locks can fail. I don’t always heed that wisdom, but I remember it like yesterday.

Anyhow, your Sebenza looks well loved. Has it ever given you trouble in real life use?

If it bothers you and you’ve lost confidence in the knife, our opinion is probably immaterial. It might be worth a call to CRK to see if they have any wisdom on shipping/warranty work from Canada. The crap CBSA is causing you guys really ticks me off.

ETA: And I hope you get/stay well.
 
Hmmm.

From what I have seen in your video would warrant concern for me.

That said, I don’t own one to compare.

I would call them and see what options you have.

Stay well.
 
I'm from Canada as well and wouldn't hesitate to send the knife in for warranty. It seems like the issue is bothering you--I'd message CRK customer service and they will get you sorted out. FWIW, I just received mine back from a spa treatment and had zero issues with CBSA.

Take care.
 
4mer_FMF said:
I’m hesitant to call it normal, but it did seem as though you really had to put some force into it on the first video, and after you flexed the lockbar a few times without a full close/open cycle. The lockbar probably isn’t designed to be a shock absorber.

When I was 8 my Cub Master taught me to treat all folders like slip joints, because all locks can fail. I don’t always heed that wisdom, but I remember it like yesterday.

Anyhow, your Sebenza looks well loved. Has it ever given you trouble in real life use?

If it bothers you and you’ve lost confidence in the knife, our opinion is probably immaterial. It might be worth a call to CRK to see if they have any wisdom on shipping/warranty work from Canada. The crap CBSA is causing you guys really ticks me off.

ETA: And I hope you get/stay well.
Click to expand...

That first video was more to show the flex for the recent 31\ 21 discussion. They all talk about how the lockbar gets pushed upwards a bit and the blade rocks.
I wanted to show this flex also. Wanted to make sure the lockbar fits into the video frame. I applied pressure gradually, in segments so one can get a better idea of how much force it takes to fail.
What happens here is the bar getting pushed outwards. Which is normal to me, there is a slope in geometry. But, at the very end the lockbar has to catch and seize. Geometry has to support this. This is how it works in a proper lock. Plus, not having a steel insert should only benefit the sebenza and catch better and not let go. I think titanium can create more friction vs steel on steel.
Anyways, thanks for the kind words and some wisdom, appreciate it.
 
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I like to show visuals as English is not my first language.
Here is what I am talking about when I refer to the lock as being properly designed.
fB3pzUV.jpg

(This lock is not not behaving like aforementioned)

Lets break down why the pictured lock doesn't slip or not prone to slipping.
You see there is almost a 90 degree angle at the beginning of the lockface where the engagement is observed ^.
Even if the lockbar would be perpendicular here it would not be prone to slipping.
The cool part is the lockbar is not perpendicular, it comes in at an angle of its own. This further adds to the forces this lock can withstand. Another force working for the lock is the pressure from the lockbar itself generated by it's bend.

In the CRK speciment it's not so obvious. It's got a detent ramp for your convenience that takes away from the visualization and possibly aids in further slipping functionally. That and the rest of the lock going deeper is a slippery slope on mine. The lockbar also is beveled which might affect things. So you see I am getting tired to iterate here.
The people who don't think it's a problem, to me, are brushing this under the rug.
And am a bit disappointed you would let things like these slide.
 
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If I understood what your issue is I would make a comment on the videos. Making the lock fail on any knife is not the intended use of the knife.
If you feel the knife is unsafe, don’t use it. If you think it’s defective, send it in. Email CRK the video you posted here so they’ll understand what the issue is. If you’re satisfied with the results once you get it back, keep it. If not get rid of it.
I’ve never had any issues with the CRK’s I own. Of course, I carry mine in a pocket sheath. When I need to cut something, I take whichever CRK I’m carrying that day out of the sheath, open the knife, use it and then move the lock bar over enough to clear the blade and fully close the blade. Then it goes back in the sheath and in my pocket. Rinse, repeat several times a day.
I have used the false edge on my Umnumzaan to scrape paint off PVC pipe. Then I got to thinking, that’s dumb on my part. Stopped doing that because I realized I wasn’t using the knife for it’s intended purpose. I guess we all do dumb things with our knives from time to time.
 
Sergeua Sergeua My second question was just from one of the videos. I thought you were moving the lockbar back towards the handle slab (unlocking it a little) and showing that the blade was folding when the lockface wasn’t fully engaged. That’s just what I thought I saw. My 21s will do the same thing, all of my ceramic ball lockup will do the same as well. I can release that lock just a minute amount and make the blade fold. Or I could be completely off on what you were showing. I’ve been wrong before o_O
But like others have said I’d contact CRK. Very easy to deal with
 
I've never had the need to cut with the spine of a folder... so I'm very happy using the Sharp edge...all these discussion really confuse me....
new to crk and been carrying a pj31...very satisfied.
 
I made the same closings and mvmts with other custom and production ti framelocks when the 31 thread was created. No personal offense but I’m watching your videos, shaking my head. Just sell/trade it for another brand and be done with CRKs. And this isn’t a “fan boy” reaction. The majority of these “discoveries” of yours and other folks can be chalked up to: a folding knife can be made to fold, whether closed properly or misused. I’ve kicked in a locked door...I didn’t phone the door factory asking for a refund due to defect.

*It wasn’t my door.
 
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Ultimately, you're asking but you think this is a problem. If you think it is a problem, you should absolutely send it back to CRK, IMHO. There are limits to what we can say from a video without being able to inspect a knife, and the Maker is best qualified to determine what is going on and address it accordingly.

That said, how much pressure are you putting on the spine? It looks to be quite a bit, but again videos can be deceiving. To me, that determines if there is an issue. If this is an amount of force that you could apply with your thumb when using the knife or if the knife should slip during normal usage and contact a surface with the spine, it's a very big issue and the knife needs immediate service. If you are using a lot of your body weight to place tremendous force on the knife, it's not. If I was going to be performing work that would potentially place tremendous force on the spine of the knife, I'd use my ESEE 6 or another fixed blade with thick and soft steel.

Further, your pivot appears to potentially be loose, and my first hand experimentation out of curiously has found that this can and generally will cause both liner locks and frame locks (with and without pivot bushings) to 'fail' (if you consider such usage to constitute a failure) in this scenario with much less downward pressure than if the pivot is tighter.

In sum, I think you should send the knife to CRK.
 
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