Need assistance with a Umnumzaan.

ice_man

ice_man

Joined
Sep 16, 2014
Messages
2,043
Hey guys! Happy Thanksgiving!

Today I got my 2nd Umnumzaan, the first one I decided to sell after 2 days as it was too big for me at the time.

I decided to give it another shot and got a lnib one form the secondary market. However, I am very puzzled by this one. Please bear with me as I am not familiar with this CRK model.

1st question: I've loosened the pivot a little so as to let the blade move a little freely, but it is very hard to open it unlike the first umnumzaan I had before. Will this break in? I already polished the washers and completely break down and lube the knife.

2nd question: when I open and close this Umnumzaan, I do not hear any audible click. A click much like opening any 21 and the lock engages and even on closing the knife, I cannot for the life of me hear anything except a little "thump". i figured it might be the rubber on the thumblugs? I did not have this problem before with my first umnumzaan.

Thank you guys!

ice
 
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The Umnumzaan is supposed to be silent. That is the idea and purpose of the o-rings.
 
kidcongo said:
The Umnumzaan is supposed to be silent. That is the idea and purpose of the o-rings.
Click to expand...

Thanks kid! Did not actually know that. My first one was not silent at all.. Lol. It clicked open and close like a Sebenza...
 
That's all I hear on mine, is a little thump. Try pushing up on the thumb lug as opposed to a arcing method for the 21 and 25. It will have a break in period and get easier to open.
My old style pivot Umnumzaan is way smoother than the newer style pivot. The ones I have make the thump and that's it.
Your first one could have had a flat spot on the O-ring that caused a distinct 21 sound.
 
Worn O-rings will let them be noisier, but they should be pretty quiet. Ajack60 is also very correct in the push deployment advice. My murdered blue old pivot tanto is the easiest opening knife I've ever owned, it is perfection. Probably a very minute amount of wear needs to occur around the detent hole in the blade, allowing the ceramic ball a slight ramp to climb out of engagement.
 
I would say that the o-rings are intended to be shock absorbers rather than sound dampeners. But practically speaking, they do both.
 
Ajack60 said:
That's all I hear on mine, is a little thump. Try pushing up on the thumb lug as opposed to a arcing method for the 21 and 25. It will have a break in period and get easier to open.
My old style pivot Umnumzaan is way smoother than the newer style pivot. The ones I have make the thump and that's it.
Your first one could have had a flat spot on the O-ring that caused a distinct 21 sound.
Click to expand...

Thanks for the explanation Ajack! My thumb's muscle memory is just so used to the 21 that I make the same arching movement rather than push most of the time last night.

The moment I got it yesterday, I just can't understand why it was not making any clicking sound. I figured that it might be the rubber washers but just got me really confused. Did not honestly know that the Umnumzaan was designed to have a quiet deployment. Lol
 
Officer's Match said:
Worn O-rings will let them be noisier, but they should be pretty quiet. Ajack60 is also very correct in the push deployment advice. My murdered blue old pivot tanto is the easiest opening knife I've ever owned, it is perfection. Probably a very minute amount of wear needs to occur around the detent hole in the blade, allowing the ceramic ball a slight ramp to climb out of engagement.
Click to expand...

Lol. I bet my first umnumzaan had 2 really worn out O-rings. I was not able to find out as it was with me for only 2 days before I sold it off.

I think you are probably correct about the detent hole. It really still is a new knife, so that is definitely the case.
 
powernoodle said:
I would say that the o-rings are intended to be shock absorbers rather than sound dampeners. But practically speaking, they do both.
Click to expand...

Essentially, now that I understand a little about the design of the Umnumzaan, I think the o-rings serve both purpose perfectly.
 
By the way guys, I did not get any tools, grease and locktite with this one. Does CRK send / sell the tools for the new pivot? I know I can buy from Home Depot or something, but just wanted one from CRK anyway.

Also, is the locktite absolutely necessary? If so, where do I actually put them? Do I buy the red locktite or the blue one?

And lastly, what size are the o-rings? Will the ones sold off the shelf be okay to use?

Thanks guys!
 
CRK uses purple locktite, which can be tricky to find. Blue is ok, but only use a tiny amount (same for purple). It may not be necessary, it is there to hold your desired position in terms of pivot tension/tightness. It may or may not hold that adjustment on its own. As for O-rings, hopefully other's with experience can chime in, as I've never replaced mine. I do recall someone posting about replacement O-rings causing earlier lockup, but flicking still allowed the CRK later lockup.
 
Officer's Match said:
CRK uses purple locktite, which can be tricky to find. Blue is ok, but only use a tiny amount (same for purple). It may not be necessary, it is there to hold your desired position in terms of pivot tension/tightness. It may or may not hold that adjustment on its own. As for O-rings, hopefully other's with experience can chime in, as I've never replaced mine. I do recall someone posting about replacement O-rings causing earlier lockup, but flicking still allowed the CRK later lockup.
Click to expand...

Thanks for the response OM. Do I put the locktite on the threads of the pivot screws? I noticed when I disassemble last night that there were some residue on the pivot screw threads.

So you have not worn out an O-ring yet on your Umnumzaans? Ok, I guess I'll not worry about it anymore.. [emoji16]
 
As for O-rings: a guy known here as Andrew Nik once replaced O-rings. He bought them in a radiocontrol toys store (Silicone O-Ring P-3). OD 6 mm, ID 3 mm
http://www.amazon.com/HPI-Racing-6819-Silicone-O-Ring/dp/B000BLNS0W
1078484.jpg

1078485.jpg

pictures by Andrew Nik
 
rings are available in many colors including glow in the dark

id suggest locker is mandatory for care free performance (NOT red)
 
unit said:
I'd suggest locker is mandatory for care free performance (NOT red)
Click to expand...

What is "locker"?

My orings are worn. I use my Zaan for work a lot. I bought my Zaan new. It was quiet for a few months, but it clicks open and closed now and has for maybe the last 5-6 months. I have rotated the orings over time which kept it quiet, but it doesn't matter anymore. It clicks no matter what.

I'm fine with it clicking open/closed, but I'd like to get replacement orings for it that don't wear out as quickly. It is nice when my Zaan opens and closes quietly.

Anyone have a link to what orings we can buy to solve this?
 
socom1970 said:
What is "locker"?

My orings are worn. I use my Zaan for work a lot. I bought my Zaan new. It was quiet for a few months, but it clicks open and closed now and has for maybe the last 5-6 months. I have rotated the orings over time which kept it quiet, but it doesn't matter anymore. It clicks no matter what.

I'm fine with it clicking open/closed, but I'd like to get replacement orings for it that don't wear out as quickly. It is nice when my Zaan opens and closes quietly.

Anyone have a link to what orings we can buy to solve this?
Click to expand...

O rings are cheap..Just buy a bunch of them and swap them out when you reach unbearable. Unfortunately, I don't think any O rings exist that will last forever- It's just a function of the operation that the O ring has to have a somewhat soft durometer (hardness measurement) to absorb the impact.
 
socom1970 said:
What is "locker"?

My orings are worn. I use my Zaan for work a lot. I bought my Zaan new. It was quiet for a few months, but it clicks open and closed now and has for maybe the last 5-6 months. I have rotated the orings over time which kept it quiet, but it doesn't matter anymore. It clicks no matter what.

I'm fine with it clicking open/closed, but I'd like to get replacement orings for it that don't wear out as quickly. It is nice when my Zaan opens and closes quietly.

Anyone have a link to what orings we can buy to solve this?
Click to expand...

Probably means "thread locker" like Locktight.
 
bhyde said:
O rings are cheap..Just buy a bunch of them and swap them out when you reach unbearable. Unfortunately, I don't think any O rings exist that will last forever- It's just a function of the operation that the O ring has to have a somewhat soft durometer (hardness measurement) to absorb the impact.
Click to expand...

Hi bhydr, do you happen to know what size O-rings we need to get for the umnumzaan?

Thanks!
 
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