Recommendation? What should I do with my ZT(framelock issue)?

Discussion in 'General Knife Discussion' started by Gideons, Jun 14, 2018.

  1. Mo2


    Apr 8, 2016
    I don't care about what he says these knives should not fail on spine whack. Especially because they are advertised as hard use.
    Last edited: Jun 15, 2018
    jux t likes this.
  2. unwisefool

    unwisefool Gold Member Gold Member

    Jan 22, 2007
    My 620 was one one the very first runs and has a pretty strong detent and lock engagement, did something change?
  3. b00n


    Dec 15, 2016

    (I don't know either, I like a locking knife so it doesn't close on my fingers, I never understood the spine whacking.)
  4. Lapedog


    Dec 7, 2016
    I wouldn’t normally bend the lockbar to remedy this issue but I had the exact issue with the exact same knife and bending the lockbar to add just abit more tension 100% fixed the problem.
  5. Rival1314

    Rival1314 KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Aug 17, 2012
    I agree, they are coming from the factory tuned for optimal flipping and it suits the needs of the vast majority. I simple tuning of the lockbar would change the lockup strength, as well as better suit it for a spine whack test. This would be the knife equivalent of tuning your car before a race, or studying for a test (albeit a completely stupid test imo, the validity of which has been debated in numerous threads on this forum). In that video it also appears that the source of the "lock rock" could possibly be addressed by adjusting the pivot and handle screw tension, similar to how one would adjust centering. Also, multiple whacks on a surface hard enough to force a fail could end up putting more wear on the lockbar (rounding the normally sharp edge of a lockface), making future fails more likely.

    The likelihood of any of those knives failing during any routine, or even "hard" use scenario (even the RAT which he forced a fail on) would be extremely unlikely even without adjusting the lockup. The added natural resistance of your hand grip on a frame lock also helps prevent a lockup fail. If this issue were so prevalent that it was causing failures leading to injury there would be plenty of threads with supporting evidence of such failures, or worse case possibly even force a consumer action such as a recall. To my knowledge Gerber is the only major knife company to issue recalls due to lock failures, and the threads resulting in injury are almost always attributed to user error or explainable circumstance.

    To the OP, if you aren't comfortable tuning the lockup I would agree with the others that sending it in makes sense. If you have a knife smith or local maker nearby that could make the adjustments on your behalf that may also be an option.
  6. Lapedog


    Dec 7, 2016
    @Gideons I was going to say if you’re ever in the Toronto area I could potentially adjust the lockbar for you.
  7. jill jackson

    jill jackson

    Sep 5, 2006
    I just tried the big bad ZT 0909 on a roll of tape and it failed like I've seen cheap knives fail. Didn't even hit it hard at all. Brand new knife too.
    kniferbro likes this.
  8. jill jackson

    jill jackson

    Sep 5, 2006
    It has no lock rock and looking close at the liner lock it only locks on the inside edge of the liner lock. Can't get it to move at all by hand pressure, my dad who is many times stronger than me couldn't either. I think the shock is just bouncing the lock loose when it's hit.
  9. Gideons

    Gideons Gold Member Gold Member Basic Member

    Dec 9, 2015
    The test I was doing was purely hand pressure and the framelock was slipping towards disengaging. Thats the thing, I'm not talking about any sort of spine whack test at all, just pure pressure from my hands, no jarring or impact that would cause it to slip.
    AmosPaul likes this.
  10. Gideons

    Gideons Gold Member Gold Member Basic Member

    Dec 9, 2015
    That is a very nice offer, that could (possibly) be discussed in the future. However I have no plans in the future to be in toronto.
  11. Gideons

    Gideons Gold Member Gold Member Basic Member

    Dec 9, 2015
    Has any fellow Canadians recently bought or had a knife repaired and ship from the US to Canada?
  12. Lapedog


    Dec 7, 2016
    Ok maybe you could mail them if talks with ZT CS doesn’t work out.
  13. Ralph Merlino

    Ralph Merlino

    Dec 26, 2004
    Just send it too ZT and they will make it right, no problem.
  14. sharp_edge

    sharp_edge Gold Member Gold Member

    Jul 30, 2015
    Lock rock? Sure I believe ZT CS will fix. Lock slip? I am not sure. At leat I have never heard such a case that is fixed by CS.
  15. AmosPaul

    AmosPaul Gold Member Gold Member

    Dec 17, 2014
    My ZT 0909 lock readily fails with very light taps on the back of a padded office chair. Not whacks, mind you, just taps. However, it is one of my favorite knives. The ergos and blade shape are just perfect for a large utilty/work knife. I just use it like I would a large traditional slipjoint and I don't use it for heavy piercing cuts.

    It's too bad really, ZT has the machining skill to make a decent lock. I don't think the lock needs to be up to CS standards, but it shouldn't fail with light taps on a padded surface.
    Mo2 likes this.
  16. AF

    AF Gold Member Gold Member

    Jan 14, 2000
    No way I could live with that. It would drive me crazy. However, I don't spine whack so unless there's play apparent from a vigorous wiggling of the blade, I wouldn't even know. I wonder if your knife has play if gripped by the tip and firmly wiggled.
  17. AmosPaul

    AmosPaul Gold Member Gold Member

    Dec 17, 2014
    No blade play whatsoever. I really should send the knife in to ZT, but I carry it so much I would miss it. By the way, I'm not spine whacking, just lightly tapping on the top of a padded office chair.

    The lock doesn't fail with medium hand pressure on the back of the blade (I haven't tried hard pressure; I'm a little afraid to do that).

    Only the very edge of the lock bar contacts the blade tang. It is an extremely small contact area compared to other liner locks.
    AF likes this.
  18. AF

    AF Gold Member Gold Member

    Jan 14, 2000
    Oh, in that case I would be aware of an issue. I always inspect for lock geometry. Send it in! I imagine you'd love it even more without that issue.
    AmosPaul likes this.
  19. Vicarious Reality

    Vicarious Reality

    Apr 9, 2008
    Sure wish i could bend my Lionsteel Ti-Spine lock bar... the thing barely keeps locked... with the clip pushing on the lock...

    My previous one had the same problem
  20. jill jackson

    jill jackson

    Sep 5, 2006
    Mine is the exact same. Liner lock only contacts the inside corner. It too is easy to tap and make fail. Spyderco Military has full contact on it's liner and won't be spine whacked to failure. I have a number of ZTs and I'm afraid almost to try to see how they fare after seeing the video where all of that guy's did.

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