New umnumzaan very difficult to open

First of all, I really wanted to love the umnumzaan, as with my sebenza, and could hardly wait until one was available. So to say I am disappointed is indeed an understatement.

Reeek, it was no better trying to open it with my left hand than with the right.

As for the plastic wrench setup, I tried it without inserting the allen wrenches at first, but the lockup was too tight to loosen the bushing. Trying to use them with the allens was an exercise in futility.

The situation reminded me of an Old Chinese Proverb, "Insanity is doing the same thing over and over and expecting a different outcome.”

If I get a reasonable response from CRK, including a willingness to test the knife to ensure it opens smoothly before sending it on, I will probably get another one.

The times that it did open, I loved the look and feel.
 
I haven't actually handled the plastic wrenchs myself, my take would be to put allen keys in first, then hold the two in the knife and twist. Also, mine didn't have loctite in it. A good idea when taking something apart that has it is to run hot water on the pivot for a minute, like steam rolling off hot. This will melt the loctite. Medium strength loctite has to be removed with it, or a good impact:)
 
The kit is so easy to use it is mystifying how someone couldnt do it.

One tool in one hand, one tool in the other, knife in the middle. Hold the allen wrenches in the holes while you are doing so. Do you only have 1 finger on each hand?
 
Sarcasm is a very poor substitute for compassion, helpfulness, and understanding.

Inserting the allen wrenches caused the plastic tools to fall out of the pivot screw holes, endlessly, no matter what I tried. Perhaps I inserted them incorrectly??? Or perhaps the lockup was so tight that I could not maintain a good grip on the allens, and so the plastic wrenches fell out of the very small holes in the screws.

But clearly I should not have to perform this on a brand-new $400 knife!

YMMV.
 
Last edited:
merlinus said:
Sarcasm is a very poor substitute for compassion, helpfulness, and understanding.

Inserting the allen wrenches caused the plastic tools to fall out of the pivot screw holes, endlessly, no matter what I tried. Perhaps I inserted them incorrectly??? Or perhaps the lockup was so tight that I could not maintain a good grip on the allens, and so the plastic wrenches fell out of the very small holes in the screws.

But clearly I should not have to perform this on a brand-new $400 knife!

YMMV.
Click to expand...

The wrenches are easy to use, once you have used them once or twice, CK has pretty good instructions with them. I do think by that time though, you were pretty frustrated which is understandable. My advise would have been to call CRK (after trying the tips we gave) and have them make it right, and they would have made it right, no questions asked..........It is a different knife though, and does not open like a sebenza at all and if you were initially trying to open it like the sebenza, that's where your thumb became sore.
 
merlinus, you're a computer tech right? I built a computer in January with a Asus P67 board.Sure you know the story behind that. That and the GSkill ram was bad. Both great companies like CRK. It happens. You never gave the knife a chance to break in, as every post I've read about the Umnumzaan says is needed. This is also the first time I've read that someone couldn't use the CRK tools for the umnum. Gimme a few minutes and I'll post a pic.

imag0118rf.jpg


imag0117b.jpg
 
Last edited:
Thanks, nyefmaker and ssblood, for your feedback. In hindsight, my frustration, and probably lack of faith in the manufacturer (been burned too often!) led me to return the knife, in fear that it would never break in and I would be out $400.

But I never read anything about the need for a break-in period in my research, and the folks at CRK customer service did not mention it either.

And I probably did not insert the allen keys into the plastic wrenches properly.

No doubt in near future I will give it another go... unless, like Joe, I head down Mexico way with a gun in my hand. :D
 
Also, if you do decide to get another one merlinus, I would advise against using a pair of snap ring pliers like I do. Because the holes in the pivot are not chamfered the movement of the snap ring pliers will dent the top of the pivot where they enter. Sorta deforms the metal just a little bit. It bothers me slightly but I choose to be impatient :) This is probably the exact reason the tools are made out of plastic instead of another metal, especially forged steel snap ring pliers:D
 
ssblood, your use of snap-ring pliers is a great idea! Never mind the slight dents, it's a whole lot better than those plastic thingies! :D

Now all I need is some close-up photos of how to place, and hold, the allen wrenches in the plastic ones.

BTW, my arcane reference to Mexico with a gun in my hand was Jimi's "Hey Joe."
 
four_shore said:
reeve would be a total genius if he made knives that opened comfortably.
Click to expand...

Hallelujah brother. I really like my new 21 small Sebenza, but it is stiff to open. I took it apart and there was no lube in it, but it really didn't make a difference after I gave it a light dose of the Reeve lube. The opening studs are useless on mine with the small and relatively pointy rounded tops - HUH? They look nice, but on the small Seb, there's hardly any space to squeeze your finger in there next to the stud so you can weasel the blade open. Plus, the pointy studs make my fingers sore. Honestly, I'd prefer to simply have a long pull nail nick to open it.
 
Last edited:
I wish I had them I'd make a video for you. The dents are very insignificant. Reminds me of the paint on Emerson screws :) I can't even cut nothing now. If you slid the allen key all the way in and hold the tool and key as one piece. Palm the knife and use the thumb and pointer to hold the bottom tool then use the other one on the side without the clip. I don't think you can turn the pivot pin, just the screw side. The pivot is all but an interference fit in the handles and blade. You could loosen the screw side have a turn and still not have blade play due to the tolerances.

This is a standard pivot done right IMHO. Loosen and Emerson or Strider half a turn and you will have blade play. My Umnumzaan doesn't. The biggest resistance I encounter in mine is the ceramic detent ball. I'm using only Miltec1 until I can order the grease Monday.

Almost seems like I was ranting but I hope this explains it better. The tolerances are just so tight that some things are going to have to be abraded (sp?) or polished by use to get it operating smoothly.

David
 
I must admit to being a tad confused at how folks can have so much trouble opening (or closing) the knife.
The studs are rounded and a bit less easy than on some knives, but if you don't need split-second samurai combating capability, I've never had an issue with them.:)
I personally like the less exposed cut-out for closing as it makes it harder to accidentally disengage the lock while using the knife.
 
The studs took getting used to for me. Been relying on holes or discs for a long time :) the cut out for the look is great and it doesn't make my thumb sore unless I try to open and close it 50 times.
 
The break in period for my brand new Zaan was about 3-6 openings and that was just to defeat the detent. My knife was CRK smoooooth right after a few openings and once you realize you push the studs toward the front of the knife and use the normal frame lock avoidance of squeezing the lock bar against the detent, it is everything I expected. So my point is, the "break in period for mine was about 10 minutes before super smooth and easy opening . . . What break in period?

Maybe the OP's knife got locked down too tight on the pivot before the Loctite set and wasn't tested after the assembly. I'm inclined to believe that it you have a hard knife to open with two hands, the pivot is too tight or something else is wrong. This isn't rocket science . . .

I think he needs to be cut some slack.

For what it's worth.
 
stabman said:
I must admit to being a tad confused at how folks can have so much trouble opening (or closing) the knife.
Click to expand...

I agee! I have had (all brand new) a small 21 Sebenza, Large Regular Sebenza, Umnumzaan and a Strider SNG. I have never had any problems opening any of them and never had any sore thumbs. I found the Umnumzaan disassembly tool very easy to use. Maybe I got lucky and got all the ones that are easy to open. :)
 
ssblood said:
I wish I had them I'd make a video for you. The dents are very insignificant. Reminds me of the paint on Emerson screws :) I can't even cut nothing now. If you slid the allen key all the way in and hold the tool and key as one piece. Palm the knife and use the thumb and pointer to hold the bottom tool then use the other one on the side without the clip. I don't think you can turn the pivot pin, just the screw side. The pivot is all but an interference fit in the handles and blade. You could loosen the screw side have a turn and still not have blade play due to the tolerances.

This is a standard pivot done right IMHO. Loosen and Emerson or Strider half a turn and you will have blade play. My Umnumzaan doesn't. The biggest resistance I encounter in mine is the ceramic detent ball. I'm using only Miltec1 until I can order the grease Monday.

Almost seems like I was ranting but I hope this explains it better. The tolerances are just so tight that some things are going to have to be abraded (sp?) or polished by use to get it operating smoothly.

David
Click to expand...

I use the Militec-1 as well, Ive compared it to the fluorinated grease and I much prefer the Militec.
 
Deleted post. Issue better handled by contacting CRK for clarification.

merlinus, out of curiosity was your problem with the detent or once it was passed that point. I ask because your umnum was from NGK and probably in the same batch as mine.

Thanks
David
 
Last edited:
Reeek said:
The break in period for my brand new Zaan was about 3-6 openings and that was just to defeat the detent. My knife was CRK smoooooth right after a few openings and once you realize you push the studs toward the front of the knife and use the normal frame lock avoidance of squeezing the lock bar against the detent, it is everything I expected. So my point is, the "break in period for mine was about 10 minutes before super smooth and easy opening . . . What break in period?

Maybe the OP's knife got locked down too tight on the pivot before the Loctite set and wasn't tested after the assembly. I'm inclined to believe that it you have a hard knife to open with two hands, the pivot is too tight or something else is wrong. This isn't rocket science . . .
Click to expand...

Exactly. Thank you!
 
ssblood said:
merlinus, out of curiosity was your problem with the detent or once it was passed that point. I ask because your umnum was from NGK and probably in the same batch as mine.
Click to expand...

If I could get the knife part way open (about 50% or so), the rest was relatively smooth.

IIRC, the birthdate was 20 April 2011.

And many thanks for your suggestion about how to use the wrenches. It will come in very handy should I decide to purchase another one.
 
Last edited:
You must log in or register to reply here.
Back
Top