Zero Tolerance Liner Lock Closures?

[sharp_edge]

The only ZTs I own are an 0350 and an 0400, and I just checked them. I lightly spine whacked them against the heel of palm of my hand, and luckily they didn't fail. I've had both of them for years, but admittedly I haven't used them much at all. I did the same with my Spyderco Military. Even though the ZTs didn't fail, my Military felt more solid when doing that than my ZTs did, even though at first glance, the Zts "look" stronger.

I really don't habitually spine whack, but tend to use hand pressure to the back of the blade as a test.

Jim

There is actually an easier way to check if the framelock will fail due to negative pressure without smashing the spine. Just lightly tapping the spine when the blade is locked open. If you can hear the noise of metal hitting metal (that's the lockbar or lockbar insert contacting the blade tang), increasing the strength of tapping/whacking will most likely disengage the blade. If all you can hear is the sound of the spine hitting the surface, then the knife is good to go.

 

[Yonose]

I’ve just tried to reproduce the lockslip as shown in the videos. Mine is ser. # 4417 and I couldn’t get it to slip, moving up to wood to see if it would hold, which it did. I wonder if this is an issue with earlier serial numbers in this case and some of the other knives, or if it occurred throughout the entire run. My 0804cf is earlier, #0482, no slip, and my 0562cf is #10683(also no slip). I haven’t checked any of my backups yet.

 

[stabman]

I'll keep buying and using them.

 

[Yonose]

I'll keep buying and using them.

Me too, but I’ll test them right after I purchase them just in case. Btw, I didn’t see an 804cf in the pics, considering that they’re $200 right now, down from $280, just saying...

 

[stabman]

Me too, but I’ll test them right after I purchase them just in case. Btw, I didn’t see an 804cf in the pics, considering that they’re $200 right now, down from $280, just saying...

I have an 0804CF as well.
It is in different pictures, doing much the same sort of thing.

 

[Yonose]

I have an 0804CF as well.
It is in different pictures, doing much the same sort of thing.

Ok, now I’m jealous, since I couldn’t get a 0561!

 

[stabman]

Ok, now I’m jealous, since I couldn’t get a 0561!

They have had some really nice ones over the years.

 

[bobobama]

Stabman to the rescue!

 

[stabman]

Stabman to the rescue!

I also decided to try a couple knives with spine whacks on my leg and knee, and all I got was a bit of a sore knee.
Not going to go whacking them all, or bashing wood with the spine, because well, I just don't bother with that.

 

[bobobama]

I hear ya. This whole threads gotten kinda whacky.

 

[jill jackson]

The main problem is ZT is not fixing their knives that have problems. Not that some of them are okay. Small consultation for people with bad locks getting them back still with a bad lock. For the price charged all of them should be good.

 

[stabman]

I hear ya. This whole threads gotten kinda whacky.

 

[Lapedog]

Nor would my $40 concierge.

How you liking that concierge btw? That is a really awesome looking knife! It’s not assisted I hope.

I kind of want to get the Natrix with the cf inlays (non assisted) in hand to check out its construction too. If it has minimal steel liners and the knife is mostly built out of g10 I think it could be interesting. Also wanna check out the bareknuckle if its not assisted and aluminum frame.

It sure appears that way. Liner/frame locks rely on proper contact geometry. It needs to be an acute enough engagement angle for the coefficient of friction/contact forces to keep the lock in place, but enough of an angle to allow for wear over time. That's a delicate balance and it's something that a number of knife makers have ignored over the years, to their detriment.

Spyderco makes their knives with a concave blade tang and it locks properly. A number of ZTs apparently use a lockbar/tang engagement geometry that lets the lock slip, which seems to me to be a result of a steep angle.

Those concace radiused lockfaces are hard to get right too. Strider’s entire lock rock issue in the past was due to the concave lockface being a portion of a too small hypothetical circle. For the radiused lockfaces to work it seems like one needs to have the curve be very slight.

Also the shorter the lockbar the tighter the circle the end of the lockbar’s motion is a portion of will be. The motion of the end of the lockbar traces a section of an imaginary circle. A longer lockbar means a bigger circle. A shorter lockbar means a smaller circle and thus the lockface of the lockbar will pull down (towards the butt direction) more quickly as it moves to a higher % of lockup. Apparently it was the very short lockbar on the Spyderco Tuff that caused lockrock issues for that knife.

 

[Lapedog]

The problem of your proposed fix is that if not done precisely, it will result in lock rock and also potentially void the warranty.

Yeah but if the warranty is them not fixing your knife anyway...

Still I agree. I wouldn’t mess with the lockfaces.

The guy in the video needs to send ZT those videos of their “repair job” and demand the knives be replaced with working models.

 

[SpySmasher]

How you liking that concierge btw? That is a really awesome looking knife! It’s not assisted I hope.

Not assisted. This is what I posted in the "Budget Knives From Last Year" thread:

I got it. It's good.

May have the best clip ever. I know it's slightly crazy to mention the clip before anything else about the knife but it's that good: easy on, easy off, grippy, almost no hotspots.

Cheap steel. VERY good looking for $40. Decent flip. Decent size.

This could be a real favorite for EDC if people take notice.

 

[Lapedog]

Not assisted. This is what I posted in the "Budget Knives From Last Year" thread:

I’m surprised more people haven’t noticed. I think the concierge is their most compelling knife since the kershaw emerson collabs.

The clip is actually revolutionary. Simple ideas are always the best it seems.

Seems all the focus has gone to the far more boring Atmos (or whatever its called, the other sinkevitch design) they’re even releasing a ZT version of the Atmos, which is ugly imho. A ZT concierge would be hugely interesting. Hopefully they’ll fix the damn lockups before they make a ZT concierge.

How does the clip feel in pocket? Does it cause the knife to press up strangely against the wall of your pocket oddly?

 

[SpySmasher]

How does the clip feel in pocket? Does it cause the knife to press up strangely against the wall of your pocket oddly?

Not that I can sense. I will admit that I'm happying pocketing almost anything but really behemoth knives.

 

[hexenjager]

After reading this thread I checked my 0909 with light taps on a roll of tape at first and working up to smacking it pretty darned hard. No failure or visible sign that the lock bar had moved. The serial number on mine is fairly low, in the mid 0900's. Just adding another data point for those trying to figure out if there's a pattern or if getting a good or bad lock is just luck of the draw.

 

[peterbright]

I've never had a knife close on my hand even those without "locks", never shot a weapon except aimed where I wanted it to hit, I could go on and on. When using a deadly weapon of any kind, stay out of its "line of fire". Blades should be "aimed" only at what you intend to cut, and your eyes should be on the blade.

 

[ScooterG]

I've never had a knife close on my hand even those without "locks", never shot a weapon except aimed where I wanted it to hit, I could go on and on. When using a deadly weapon of any kind, stay out of its "line of fire". Blades should be "aimed" only at what you intend to cut, and your eyes should be on the blade.

Fixed blades only then, by this logic.