ZT 0452 lock up

jill jackson

jill jackson

Joined
Sep 5, 2006
Messages
20,593
Is this the new standard for lock up on the newer ZT's? I was reading about another member's experience with his ZT 0452's lock up bar traveling all the way over with use and by being pushed. I thought my new one won't do that. (surely not) So, I try it and sure enough it's lock bar pushes right over, with moderate thumb pressure. There seems to be only a corner of the steel insert making contact. So, I have to ask is this the way all of them are? And yes it takes two hands to unlock it when the bar is over that far. Brand new knife below never used, just pushed the lock bar right over.


241mbzs.jpg
 
Mine didn't seem to either, lock up seemed early and solid, but I can just push it right over with my thumb. Lock up returns to normal afterwards and seems solid. Should I return it to ZT?
 
Had mine for a week and it does not do this. I also saw this issue talked about in a couple of different places. Seems that some 452's have this problem. More of them have the problem of a super strong detent--which mine had. On a few of my ZT's like my 452 I put a small wedge in the knife when I was not using it to expand/loosen the frame lock.

Mike
 
Mine is fine just flipping it, but the lock bar seems ill fitted to travel so easy all the way over.

wsmi47.jpg
 
Yeah it was Blues Bender's 0452 that does that as well.

That's not normal or desirable.
 
I wonder if there's a lot like this with "mushy lock ups" and people just don't know it because they haven't used the knives, or tried to push the bar over? (that's what I'd call this lock up mushy, because it's not solid once you start checking it out) I have seen lock bars move some with pressure but not all the way over like this.
 
I found this on the problem.

[video=youtube;0cC-EJh4pD8]https://www.youtube.com/watch?v=0cC-EJh4pD8[/video]
 
Part two, I don't have time to watch it all but skipping ahead it seems they were sent back and ZT only somewhat fixed the problem. (at least on one knife, didn't watch about the other yet)

[video=youtube;l8UWOARBORA]https://www.youtube.com/watch?v=l8UWOARBORA[/video]
 
It's unfortunate that this problem is compromising the reputation of an otherwise excellent knife, but it's something ZT would be better off addressing with a next-gen fix instead of ignoring. A change in the tang-side lock-face bevel of 1 or 2 degrees might help; they could also try a 'reverse over-travel stop' ('under-travel stop'? -- a ledge on the lock-bar face protruding slightly higher, hitting the side of the tang and preventing the lock-bar from moving in). Both of those solutions can have complications of their own, however, from 'slippage' -- if the bevel angle gets much above 7-degrees -- to lock-rock.

I haven't heard any similar complaints about the 0450 or the original 0454, which makes me wonder if it could be related to a discrepancy between the flexibility of the carbon fiber and titanium scales. Another possible factor, albeit one that applies to frame-locks in general, is that lefties using a right-handed frame-lock for hard-use may end up applying a great deal more force directly onto the lock-bar, depending on the design. I don't know how widespread this defect is, but hopefully ZT can find a reliable fix.
 
My 0452 locks up around 30% when flipped and doesn't move, no matter how hard i squeeze on the lockbar.
 
lockbars with steel inserts and flat lock faces will move over if manipulated to do so. Especially when paired with a composite handle half. To reduce it as much as possible make sure the pivot and handle screws are snug. The small corner being the only area making contact is normal and the preferred way to cut a lock by most tactical folder makers including emerson, hinderer and the vast majority of others. The idea being that a small portion of contact in that front corner is more stable. In a lot of the cases when you have full contact across the length of the lock face the lockbar uses it as a ramp and it causes lock slip.
 
A solution looking for a problem? That guy in the vid seems to want to have something wrong with the knife, the type of you tuber looking for controversy...
 
PURPLEDC said:
lockbars with steel inserts and flat lock faces will move over if manipulated to do so. Especially when paired with a composite handle half.
Click to expand...

Then why does only some of the 0452's move over and the rest are reported not to? Your statement says they will, yet some don't?
 
dano said:
A solution looking for a problem? That guy in the vid seems to want to have something wrong with the knife, the type of you tuber looking for controversy...
Click to expand...

So is there nothing wrong with the lock bar moving over when pressed that far? A few have said yes there is something wrong with it, now a couple say it's fine? I don't know myself for sure, I'm just trying to find out. Blues Bender thinks it's not normal and that's why I checked mine.
 
Sorry you got a bad one, Jill. I would send it back and see what they can do. Maybe they can get it right, and sure hope so.

I was about ready to get this knife, and my first ZT. Awesome looking knife, light weight, and it looks like it would fit my large hand well. I hate a lockbar that moves making it hard to release. I'll hold off, yet again.

Good luck, Jill. Hope they can make it right.
 
I guess t's better than moving out of lock up, but I have a lot of other knives costing in the same price range and down that won't move like that. I also have seen really cheap frame locks move over just like that. But, the higher dollar ones I have won't.
 
Jill, I'm glad that someone has brought this problem to attention besides myself. I remember when I first described my issue, fanboys jumped all over me and wouldn't acknowled the problem I described.

I have 3 ZT's: an 0452, 0454, and 0562CF. All of them exhibit the same problem you describe. I acknowledge your problem, and I stand with you in that Zero Tolerance has zero tolerance for making a good lockface.

I do a lot of cutting that require force put on the blade, such as cutting wood lath, push cutting rope, cutting thick plastics, etc. I've noticed that when doing such tasks, my ZT's lockup to the point where it requires 2 hands to close the knife; not good for a fast-paced work environment or when wearing gloves.

Personally, I have just moved away from ZT and have focused more on custom knives. The only thing "production" I really carry now is CRK's, which have proven reliable in any situation I've thrown them into. I think ZT has some unique designs here-and-there especially with some of the collaborations they've done, good for them; but they are no longer my cup of tea.
 
PURPLEDC said:
lockbars with steel inserts and flat lock faces will move over if manipulated to do so. Especially when paired with a composite handle half.
Click to expand...

If you watch the videos the guy shows a ZT 0777 that has the composite handle and it will not move over at all, so there's more to it than that. I think it's just ill fitted lock inserts to tang.
 
Ken44 said:
Sorry you got a bad one, Jill. I would send it back and see what they can do. Maybe they can get it right, and sure hope so.

I was about ready to get this knife, and my first ZT. Awesome looking knife, light weight, and it looks like it would fit my large hand well. I hate a lockbar that moves making it hard to release. I'll hold off, yet again.

Good luck, Jill. Hope they can make it right.
Click to expand...

Mine is perfect as are the rest of 6 ZTs. Not sure how to view this situation. I respect the OP and Blues and don't doubt their experience. It's just not mine and I don't know if there is enough of this issue going on to declare it a flaw or downgrade its reputation.





Mike
 
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