Zero Tolerance 0550 issue.....

jeremy1517

jeremy1517

Joined
Sep 11, 2012
Messages
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I recently purchased a ZT0550. I've never owned a 0550 but know many of you have. I've heard the knife is easy to open one handed. Mine is near impossible to open with one hand using the thumb stud. It just doesn't want to move. I've not tried to loosen any screws and haven't oiled anything. Is this a new knife issue that will get better with use or is there anything I can do?
 
You could be putting pressure on the lock bar.
Or it could just need break in time.
Maybe loosen the pivot a little.
Maybe try some Benchmade Blue Lube.
 
Take the knife apart, clean out the grease, and put some oil in there. The 0550 is not the type of knife that you can open slowly, you have to learn to flick it out because of the strong detent.
 
Its going to need a little break-in time. Push UP on the thumbstud and not outward. Take some time to open/close and the detent should get easier to work with (either that or your hands are just getting tougher). Its a great knife, just gotta give it a little time.
 
I make it a habit to always take down a brand new knife, and lube it up. Also make sure you're not putting any pressure on the lock, and it may require a break in period. And if you could comment back saying whether, or not your problem has been resolved, that would be helpful.
 
Takes time to break in - mine was super-stiff, but eventually has become one of the smoothest opening knives I own.
 
I think it's me as well. For some reason I can't seem to get the proper movement with the thumb stud. I can lightly grip the blade under the blade with my thumb and middle finger on each side of the blade it easily comes open. Not ideal and fast but I think I know it's me. I need to figure out how to open it.
 
jeremy1517 said:
I think it's me as well. For some reason I can't seem to get the proper movement with the thumb stud. I can lightly grip the blade under the blade with my thumb and middle finger on each side of the blade it easily comes open. Not ideal and fast but I think I know it's me. I need to figure out how to open it.
Click to expand...

point the knife forward with the g10 side up push forward on the thumb stud and it should open easy

It took awhile for mine to break in but I could always use the thumb studs
 
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Your pinky, ring, and middle finger should be back on the clip and not putting any pressure on the lock bar. I put my index finger up on the front corner of the knife. Your thumb should press in line with the handle. When enough force is exerted, the detent will let go and the blade fill fly open.

There is a definite break-in period with the 550, but a very large portion of that break in is in the user figuring out a proper technique, and not in the knife its self.

If you feel you have gone as far as possible with the technique and the knife just doesn't seem to be breaking in at a reasonable pace, there are a few ways to speed up the process. HERE is a thread I started on the subject a while back. It might help you out but I advise you to try and figure things out before you go modifying anything or doing anything drastic. It can take some time to get the technique figured out, but it is well worth it in the end. I have handled a lot of knives and can say that I haven't found anything to be as much of a pleasure to hold, handle, and use as the ZT550. YMMV
 
If you're right-handed like me, you may be resting your index finger on the lockbar. That additional pressure makes it difficult to overcome the detent. If you move your hand position to avoid pressing on the lockbar, it should open much easier. For me, I moved my index finger to the flat area by the pivot, and my remaining fingers rested on the pocket clip (set for tip-up carry).

There's also a break-in period before the 0550 will be as smooth as it can get. For me, it was a couple of weeks of carry and use. If you just sit and flip it open and closed repeatedly several hundred times, that may do it as well. After it's been broken in, it should be incredibly smooth. My 0550 gives my 0560 (w/ KVT) a run for its money with respect to how smoothly the blade opens.
 
I'm curious; is it a gen 1 or gen 2? In any case, all of the afore mentioned remarks are well within their rights. The issue could be that the pivot is too tight/your hand is in the wrong position/the knife is not as well cleaned or lubed as need be, etc. Another note on opening via the thumb stud: begin with your thumb pointing directly toward or on the pivot in a straight line from the butt, then move only your thumb to the point rear of the finger choil, arch your thumb so that the tip of your thumb is on the point, move your thumb swiftly to the thumb stud and follow through. If you by chance have a blur, it's the exact same form and function without the ramped thumb stud and speedsafe. Work on your technique for a few days, then I would suggest possibly adjusting the pivot. Also, if you believe the detent has anything to do with the situation you can leave the knife 1/2 opened at night, putting constant pressure on things, possibly making things work a bit easier for you.
 
I just got my 1st gen 0550 this morning and with a little flick it opens as fast or faster than any assisted open knife I currently have. It is a little difficult to open with just a thumb and no flick but I can open it that way as well and I have relatively small hands.
 
Both my 0551's open easily, and smoothly with the thumb studs. Just the right amount of resistance and retention too.
 
BenLong1018 said:
Take the knife apart, clean out the grease, and put some oil in there. The 0550 is not the type of knife that you can open slowly, you have to learn to flick it out because of the strong detent.
Click to expand...

I disagree with that statement , I've owned a few 550's and I've been able to open them all slowly without any "flicking" what so ever, like others have said make sure your not pushing the lockbar in when you are trying to open it, and give it a little time as well, It very well may need to be broken in, may i ask is it a gen 1 or gen 2 550 ?
 
I had a gen 1 550 just like this, Could hardly open it. I like strong detents too but this 550 was just too stiff. I would have kept it and broken it in but the thumbstud wasn't centered, it noticeably had more stud on the lockside so I sent it back and never got a replacement. I grabbed a 561 instead and love it. I would contact the warranty dept. at Kershaw/ZT and they'll take good care of you:thumbup:
 
My gen 2 has a super weak detent. It can fall out of the handle with the slightest of a shake. It also locks up too early and can disengage with pressure like most gen 2s. I've heard Kershaw fixes both of these issues if you send them back in. Maybe you could send in the gen 1 to have the detent weakened slightly?
 
It is a Gen 2. I can open it just fine using my left hand. This leads me to think it's operator error. I think I put pressure on the clip. I need to get a torx screw driver to move the clip. Don't know, can't seem to figure it out with my right hand. Ow well, fun to practice.
 
I had the same issue... Go to YouTube and search for something along the lines of "opening a zero tolerance 550". Seeing people do it made all the difference for me. Totally operator error on my part and as soon as I saw how it should be done it was like having a completely different knife. Good luck!
 
Update.... First off, I figured out the method of opening it. Now I don't feel so stupid. Second, I got a new scale from Kryptoglow so as I took the knife apart I made sure to clean it and lightly oil parts. After putting it together I think I overtightened the screw going into the pivot screw, impossible to open knife. I loosened it and found a point where it was easy to open. So, I think between me not being good with the thumb stud and I think the pivot screw was too tight, the knife didn't work well. Now it works wonderfully well for me. LOVE IT!! Thank you all for the great advice!!
 
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