Zero Tolerance Liner Lock Closures?

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jill jackson said:
Seeing that 0450 come back from ZT and they only marred up the lock face and it still folds tapped on the guy's hand, did it for me. They obviously don't care about the issue or lock safety. They should have never sent that knife back. If they couldn't fix it they should have replaced it.
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Yeah sorry ZT, yer done on my list until this issue is addressed. Even though I have a local shop where I can try them out I won’t support a company that will ignore this issue.

I think ZT is trying to hope that the issue will be forgotten and fade into the background because this could potentially mean a huge recall across tons of models.

I'm not expecting ZT to have to fix every faulty lock. (Particularly if marring the tang is their idea of fixing it) But I would like to hear them admit it, apologize, and make sure the issue is fixed in the future.
 
crufflers said:
My 0909 will not do it. It doesn't budge in the least. Bashed it soft and hard. Solid as a tank. FYI, no lock bar insert on this model either. Steel lined liner lock. No titanium. Serial # 0182

The liner contacting the lock face in a ZT 0909 is significantly fatter than a lock bar insert with a titanium frame lock design. But didn't someone here say the 0909 has the "problem"?
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My 0909 folds easy tapped on a roll of tape. The guy in the video with 7 ZT's that folded has one do the same.
 
Damn, and I was just looking at getting a 450 because of it’s smaller size. I guess I’ll hold off on that, at least for now. I’ll give my two 0392s a few taps and see what happens with them. Definitely won’t go crazy with that experiment, though. My 0456s never do this.
 
DRLyman said:
Damn, and I was just looking at getting a 450 because of it’s smaller size. I guess I’ll hold off on that, at least for now. I’ll give my two 0392s a few taps and see what happens with them. Definitely won’t go crazy with that experiment, though. My 0456s never do this.
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I had my 0450 this weekend. Great to carry in shorts. I didn't fold up on me cutting stuff, but I was putting pressure on the correct side, not whacking the back.

UPDATE: Did whack the back of the 0450 lots of different ways... didn't budge.
 
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crufflers said:
I had my 0450 this weekend. Great to carry in shorts. I didn't fold up on me cutting stuff, but I was putting pressure on the correct side, not whacking the back.
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And this is the reason we can't have nice things.
 
I think it's literally insane that some people here don't see a difference between some light to medium back tapping and spine whacking. No, folding knives are never meant to withstand huge whacks and wont ever face that in normal use. However, the entire point of putting a lock on a folder is to prevent accidental closure from unintended negative pressure. Otherwise, why carry a locking knife? Just carry a slip joint.

One of my favorite knives for current carry is a ZT0055 I did a lot of modifications to in order to personalize it. When I first heard about this issue I immediately took it out for some light spine tapping to see if it would pass. To my great pleasure, it did. In my opinion, you'd have to be a complete moron not to test the lock like this.
 
You should be able to tap a blade spine on a locking folder on the palm of your hand and not have it fold up. Even an moderate tap on a roll of tape should produce no failures. The big thing used to be when I was growing up is using the point on a folder to make a hole in something and you had to be careful with it, so it didn't close on your fingers. Locking folders were considered much safer than non- locking for this. Also any knife considered for self defense should be able to withstand spine taps.
 
jill jackson said:
You should be able to tap a blade spine on a locking folder on the palm of your hand and not have it fold up. Even an moderate tap on a roll of tape should produce no failures. The big thing used to be when I was growing up is using the point on a folder to make a hole in something and you had to be careful with it, so it didn't close on your fingers. Locking folders were considered much safer than non- locking for this. Also any knife considered for self defense should be able to withstand spine taps.
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Completely agree.

Sometimes I think that we (I mean forum members) get confused about what a knife should be because we are pressed by the nature of discourse to the fringes. ie. a knife should be able to be hammered through a 2 x 4 vs. a knife should only ever be used to gently slice a tomato.

In reality, no, a pocket knife should not be able to be hammered through a 2 x 4 but it should be able to withstand more than tomato slicing.
 
gotgoat said:
well I had to try it
brand new 620
5th light tap it closed, tried it 4 different times on a table top
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My ZT0620cf did the same thing. Taking the knife apart and bending the lock bar in more 100% remedied the problem. I don’t know if it will for yours but you might want to give it a try.

If you’re not comfortable doing that you could send it to ZT and ask them to do it for you.
 
I just tried this with my 0392s and again with my 0456s and they did not close on me. I gave all of them 20 hits on the palm of my hand. So now I know none of my ZT knives have this problem, which makes me feel better. That, of course, does nothing for those of you with knives that do have this problem.
 
Lapedog said:
My ZT0620cf did the same thing. Taking the knife apart and bending the lock bar in more 100% remedied the problem. I don’t know if it will for yours but you might want to give it a try.

If you’re not comfortable doing that you could send it to ZT and ask them to do it for you.
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Not sure if this trick will solve the problem being discussed in this thread for all but glad to know it worked for you. One thing I know for sure is that bending the lockbar inward will definitely increase the detent strength. So if a flipper does not flip well due to weak detent, your technique will most often be a quick fix.
 
Wow. I must say that I wasn't all that concerned after I saw that guy's knives close with hard smacks, but after hearing about these closures from light pressure and seeing that guy's close from hitting his palm I must say I am a little concered. I do value a secure lock up. As Jill was talking about I was taught by my father to be very carefull as a kid while using the points of knives that don't lock, in fact my brother once gave himself a pretty nasty cut when a Boker Tree Brand closed on him. When I stepped up to the world of lock backs like the Buck 110 it seemed much safer to me, and I'll always remember that.
If I am to encounter any problems with the lock up on my coming 0909 I planned to send it in the ZT for a fix, but after seeing their idea of a fix in that video I may simply return it and replace it, maybe with a Benchmade Adamas. Anyone know of some good alternatives? Looking for something in the 3.75" range. Probably getting ahead of myself, but planning never hurts.
 
I've had issues on a few framelock knives I've owned. My issues were not dissimilar to the guy in the video, where the knives had movement in the locks and would fail with spine taps, or at the very least would start to slip and disengage with negative hand pressure. The knives in question were a ZT0550, ZT0630, and Spyderco Military Titanium/CF Knifeworks Exclusive. I elected to fix them myself, by disassembling the knives and bending the lockbar in further to add lockbar tension. In all three cases, this fixed the issue. I know no one asked me, but in my opinion the pursuit of perfectly smooth opening within the tolerances of a factory made knife has lead to manufacturers using the least amount of lockbar tension possible. As a result, the framelock doesn't engage properly because it has inadequate tension to do so. That's just my opinion based on my experience anyway.
 
One thing to note about the 0909, it doesn't close on your fingers, if you're a dunce you might pinch your finger a bit, but I purposely tried it last time, and yes it pinched me a bit but due to the flipper tab it can't cut you and to really injury you, you'd have to literally force the blade shut to use the flipper tab to crush your finger by essentially turning the knife into some sort of weird torture device forcibly closing the knife using both your hands to do so.

Of course if you hold the knife with two fingers at the back and whack it with the intention of it just closing, the risk of the blade catching your finger when it closes is greatly increased but not when you hold the knife as intended (and when you do it's much more difficult to spine whack to begin with)
To me this practically a non issue 99.999% during normal use, the likelihood of your knife closing unintentionally while using it as a cutting device is lower than being hit by a car while you're whittling with it in the backyard.
 
GTS9 said:
Wow. I must say that I wasn't all that concerned after I saw that guy's knives close with hard smacks, but after hearing about these closures from light pressure and seeing that guy's close from hitting his palm I must say I am a little concered. I do value a secure lock up. As Jill was talking about I was taught by my father to be very carefull as a kid while using the points of knives that don't lock, in fact my brother once gave himself a pretty nasty cut when a Boker Tree Brand closed on him. When I stepped up to the world of lock backs like the Buck 110 it seemed much safer to me, and I'll always remember that.
If I am to encounter any problems with the lock up on my coming 0909 I planned to send it in the ZT for a fix, but after seeing their idea of a fix in that video I may simply return it and replace it, maybe with a Benchmade Adamas. Anyone know of some good alternatives? Looking for something in the 3.75" range. Probably getting ahead of myself, but planning never hurts.
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Axis locks I own are all very solid. Spydeco's compression lock and ball lock have been as well. Cold Steel makes the Triad lockback which withstands very hard spine whacks. Your 0909 very well might be okay. The problem is some are some aren't. Consistency is always nice!
 
Lapedog said:
I don’t think the leading edge making contact is the issue. According to Michael Walker that is how a liner ( and thus framelock) is meant to contact the tang. Thats how a sebenza contacts, thats how my Emersons contact.

I bet dispite how it looks if you were to disassemble your Spydercos and look where the lockbar is worn it would likely be only the leading (inside as you put it) edge that is actually worn from tang contact. The CRK Inkosi because of the ceramic BB lockface only contacts the tang at a single tiny point.
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A quick inspection with a great flashlight and a magnifying glass shows this to be true on my Spydercos. But I only have two. Looking at my RAT 1 (which has been beat like a rented mule), a couple of other sturdy liner lockers including my ZTs, and they are the same.

Lapedog said:
I have heard that attempting to have the lockbar face flat against the tang will work at first but lead to lock issues as it wears. Idk I don’t build locks, this was a claim from a certain Walker acolyte. But I don’t think the leading edge contact is the issue. It is something else causing the lock to skip off or slip off and fail.
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I think you are right. I had a few inexpensive work knives that were assigned job site duty (beaters) that were liner locks, and they failed. Worked OK for a while, but then the locks simply quit functioning. The culprit on a couple of them was that the liner/lock bar was so thin that it bent during normal use, the made the blade wobble and move while in use. The other problem was that the lock bar and tang were not machined at a angle, but as you say, machined flat. Worked OK for a while, but they soon failed to lock up tight. The flat grind didn't allow for any wear that takes place from repeated use.

I don't build 'em either, but that is what I saw. I personally think that ZT ran out a production run of poorly fitting knives, (worn tooling, tolerances of manufacture not set right, assembly jigs off, etc.) and is being too hard headed to fix or replace them. Building knives on the scale they do, I don't understand why it would be so hard to remedy this problem.

Robert
 
jill jackson said:
Axis locks I own are all very solid. Spydeco's compression lock and ball lock have been as well. Cold Steel makes the Triad lockback which withstands very hard spine whacks. Your 0909 very well might be okay. The problem is some are some aren't. Consistency is always nice!
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The nice thing with those locks is that they are inherently easier to make consistently. They are made using pre-made springs purpose built to apply the correct tension with machined slots and probably not much in the way of hand fitting that affects overall strength. Framelocks require a lot more hand fitting, and the locking surfaces are often ground by hand. As for tension, framelocks are set individually, usually with a jig or by hand, and are much more susceptible to human error, especially when the jigs or guidelines for tension are set to try and keep the lockbar from interfering with the "drop shut" smoothness people have come to expect from premium knives. Then if spine taps aren't part of QC, knives can be sent out the door with locks that engage, but just barely. With TriAd locks and Axis locks, odds are if the knife was assembled correctly enough for the lock to engage and disengage properly, the strength is there. Framelocks? Not so simple.
 
b00n said:
One thing to note about the 0909, it doesn't close on your fingers, if you're a dunce you might pinch your finger a bit, but I purposely tried it last time, and yes it pinched me a bit but due to the flipper tab it can't cut you and to really injury you, you'd have to literally force the blade shut to use the flipper tab to crush your finger
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And this applies to knives designed that way that have frame locks too. Plus, the failures are the lock bar going to the side just like when they are disengaged on purpose. Doesn't normal grip keep this from happening (gripping the frame and lock bar, pressing it into the lock face)? Same concept is what make some flippers hard to flip (because you are pressing the lock bar into the detent while trying to overcome it). If I have a knife that fits my hand and I have a decent grip, how can the lock bar move. I am pressing it deeper into lockup.

Looking forward to testing some tonight.
 
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