Zero Tolerance Liner Lock Closures?

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Interesting video. At first I thought he just wanted to bash ZT's, but then he got into the mechanics of liner/frame locks and really gave us some food for thought.

Ever see one of Vininull's hard use tests? I saw him do the same thing to an Emerson. Fact is, liner/frame locks can and do fail, and not just from spine whacks. I had an early Benchmade liner lock fail just using it to open a bottle of wine (don't ask) with very little pressure applied. I don't trust them anymore, but at least based on that video I have a better idea of what to look for.

Having said that, personally I'm not sure I would include spine whacks as part of my hard use repertoire:confused:.
 
I still have mixed feelings on the whole spine whack phenomenon. On the one hand, I agree with Jill that it's pretty depressing seeing an expensive folder have its lock slip after a minor shock to the spine (especially when I too have $20 folders that pass just fine). On the other hand, I've used the 0920 off and on since last year and have never had the lock slip during actual use, so does the spine whack test really mean anything in terms of real world performance and safety? I'm not sure. I mean, it seems reasonable to assume that a knife that handles spine whack tests better should be more secure and safe to use; however, since a knife can fail a moderate spine whack test yet still perform perfectly safely in actual daily use, it seems the perceived advantage of the knife that doesn't fail the test does not really translate into reality (at least in any meaningful way). :confused::D
 
G. Scott H. said:
I still have mixed feelings on the whole spine whack phenomenon. On the one hand, I agree with Jill that it's pretty depressing seeing an expensive folder have its lock slip after a minor shock to the spine (especially when I too have $20 folders that pass just fine). On the other hand, I've used the 0920 off and on since last year and have never had the lock slip during actual use, so does the spine whack test really mean anything in terms of real world performance and safety? I'm not sure. I mean, it seems reasonable to assume that a knife that handles spine whack tests better should be more secure and safe to use; however, since a knife can fail a moderate spine whack test yet still perform perfectly safely in actual daily use, it seems the perceived advantage of the knife that doesn't fail the test does not really translate into reality (at least in any meaningful way). :confused::D
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Somebody should be capable of figuring this out, rather than guessing right?
 
What I'd be interested in knowing is if this is some type of inherent flaw in their lock system or do to mess-ups in maching certain parts of the knife/quality control issues.
Anyway, if I have any issues with mine I think it would be interesting to use and test the tool in its flawed state to see if it resulted in any expectable real world implications, but instead I think I'll talk you ZT (assuming there is any problem which apparently is no gurantee) about it and see if they'll be willing to fix it as a test of customer service as well as to get a diagnosis of the problem.
Either way, I'll be sure to give updates on any developments or outcomes.
 
Mo2 said:
Zt's had this problem for a while now and they are ignoring it. I'm not gonna get anymore. Though I do want the new Shiro they are releasing later this year. We will see if it has the issue. If it does it will go right back and I'll be annoyed I wasted my time.
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ZT is releasing a shiro collab? Or did you mean to say sinkevitch?
 
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NOTE! I did not spine tap my ZT 0450CFZDP, I placed my hand gently on the spine and it closed on my hand such that it gouged the pinky of my left hand so deeply....if it had not stopped bleeding, I thought for sure, it had come close to severing the tendon in my hand.

NOTE! This is from a guy who has almost put a REAL knife through the palm of his hand... almost does not count. But it does make me wonder if I am wisely choosing my locks right.

All of this bad mouthing that goes on with regard to Cold Steel back locks being overkill. I have news for you. I have a few and none have ever failed!
 
Throwing my 2 cents into the burning ring of fire (and probably watching it melt away)... Most ZT knives close on spine whack. Some take just a tap and others take some effort. In of itself, this isn’t too bothersome. What I find it is a symptom of though is the knifes willingness to close when making a twisting motion (right handed, twisting to the right). Doesn’t come up very often at all but you never know what you’ll be using your knife for on any given day. This isn’t necessarily unique to ZT as most framelocks exhibit the same behavior.
 
Tommy-Chi said:
NOTE! I did not spine tap my ZT 0450CFZDP, I placed my hand gently on the spine and it closed on my hand such that it gouged the pinky of my left hand so deeply....if it had not stopped bleeding, I thought for sure, it had come close to severing the tendon in my hand.

NOTE! This is from a guy who has almost put a REAL knife through the palm of his hand... almost does not count. But it does make me wonder if I am wisely choosing my locks right.

All of this bad mouthing that goes on with regard to Cold Steel back locks being overkill. I have news for you. I have a few and none have ever failed!
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And very unlikely that they will. I still carry the occasional frame lock and liner lock because I very much enjoy the particular knife or they are designed in a way where they don’t close (Strider...I know :rolleyes:, Microtech SOCOM...I know :rolleyes:, BM Proxy or a CRK Zann). 95% of the time though, it’s a compression lock, back lock, axis (or similar) or a scorpion lock. I just picked up a 0550 from the Exchange and will see how that one compares.
 
ScooterG said:
And very unlikely that they will. I still carry the occasional frame lock and liner lock because I very much enjoy the particular knife or they are designed in a way where they don’t close (Strider...I know :rolleyes:, Microtech SOCOM...I know :rolleyes:, BM Proxy or a CRK Zann). 95% of the time though, it’s a compression lock, back lock, axis (or similar) or a scorpion lock. I just picked up a 0550 from the Exchange and will see how that one compares.
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Agree 100%. I have a lot of nice knives too, Emersons, Spydercos, and ZTs. I never thought would come the day I have anything bad to say abt any of them.

It's the tolerances. YOUR FINGERS are protected by 1/64th or 1/32nd of a movement to lock or unlock, so watch those fingers!
 
Tommy-Chi said:
All of this bad mouthing that goes on with regard to Cold Steel back locks being overkill. I have news for you. I have a few and none have ever failed!
Click to expand...

I would never expect a Triad lock to fail during Typical knife use, BUT 3 years ago I found out the hard way that the danger is in the unlocking and closing phase. For myself, lock safety isn't only how a knife's lock functions in the open and locked position. I dumbly tried to one-hand close a Code 4 and the blade fell shut on the last joint of my R index finger. Two months of immobilization and 2 more for rehab on the finger, and the very end of that finger still doesn't completely straighten. I also lost 4 months of works.

Now, I'm sure someone out there would say that they regular one-hand close their Code 4, and if so, great for them. I would never again try to one-hand close any Cold Steel Triad/lockback knives. The designs don't lend themselves to doing that safely. No more Russian roulette with MY fingers.

I've handled a couple of frame locks (Kershaw Vapor, years ago) in a store and from the open position, they pushed closed with light hand pressure on the blade spine. As much or less pressure than it takes to close a standard-sized, non-locking SAK.

Jim
 
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ScooterG said:
I still carry the occasional frame lock and liner lock because I very much enjoy the particular knife or they are designed in a way where they don’t close (Strider...I know :rolleyes:, Microtech SOCOM...I know :rolleyes:, BM Proxy or a CRK Zann). 95% of the time though, it’s a compression lock, back lock, axis (or similar) or a scorpion lock.
Click to expand...
Same here. I have a few liner and frame lock knives that I occasionally carry due to the fact that I enjoy the overall design of the knife but 90 percent of the time I prefer to carry something with a more secure lock like an Axis, Compression, or Tri-Ad lock.
 
I'm waiting for someone to point out the fact that you don't have this problem with fixed blades.

I know- I'm the master of the obvious:).
 
The first time I heard about this, I decided to have fun testing my four ZTs. I have 6 other knives, and have used all of them at work. This was a “nothing to lose” kind of a thing for me. Very easy to be matter of fact about it.

0550, 0566, 0562, 0609. All of the locks remained secure.
 
Personally, I can believe that his knives fail that way. I've had a number of ZTs which exhibit some form of lock motion when stressed right out of the box, and one or two of them were actually dangerous. They've never failed on me in use but I don't stab my folding knives into things, fight with them, or get them wedged into wood or other hard materials and need to yank them out. If I did, then I could see the knives causing issues. You could argue those are all tasks for fixed blades, which I'd agree with, but ZTs are generally marketed as being capable of handling those sorts of tasks.

I think it's possible that ZT has lost sight of where they came from due to market pressures. Having a sturdy lock seems to have taken a backseat to lower lockbar tension and easier flipping action.
 
marrenmiller said:
Personally, I can believe that his knives fail that way. I've had a number of ZTs which exhibit some form of lock motion when stressed right out of the box, and one or two of them were actually dangerous. They've never failed on me in use but I don't stab my folding knives into things, fight with them, or get them wedged into wood or other hard materials and need to yank them out. If I did, then I could see the knives causing issues. You could argue those are all tasks for fixed blades, which I'd agree with, but ZTs are generally marketed as being capable of handling those sorts of tasks.

I think it's possible that ZT has lost sight of where they came from due to market pressures. Having a sturdy lock seems to have taken a backseat to lower lockbar tension and easier flipping action.
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That is alot of the issue with me. Lots of these knives are marketed as being able to be pushed into a fighting role. Negative pressure is likely to occur in this environment.

Obviously every lock has some ammount of negative spine side pressure it can’t take and will fail.

To those of you who say you will never have negative pressue on the spine, that is most likely true. However what if you are on a work site and someone drops something from above striking the spine of your open knife.
 
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