Umnumzaan stiff

K

Kyle_4

Joined
Mar 21, 2013
Messages
616
I am wondering if Umnumzaans are normally not as smooth to open as a Seb 21? I bought a used one and sent it back for a spa treatment, it was very stiff upon return. After using it for a few months now, it is still very stiff whereas the other Seb 21 that went in for a spa treatment is nice and smooth again. I know how to properly open it and how it opens differently than a Seb 21. I put a tiny bit of flouro grease on the detent ball, which temporarily smoothed it out but it is stiff again.

Any suggestions?
 
Last edited:
The Umnumzaan doesn't have the bushing system that the 21 has so it's down to tuning the pivot tightness. :)
 
If you back the pivot out the blade doesn't loosen at all ? :confused:.....When you say "stiff" how would you describe that ?

Is it being slowed by tension or are you feeling some other resistance ? To word it differently, is it like waving your arm through water or rubbing your hand along the wall ? :D
 
Is it stiff when you hold the lockbar of of the blade? If so, I would think the pivot is too tight. If not, I would say that it needs to break in a bit more. The detent ball creates a track or path on the tang. If that isn't there or fully developed yet, I believe that it can feel a bit stiff until it wears in.

Did CRK mess with the detent ball or do a blade swap?

FWIW, my Zaan is not nearly as 'free' as my 21's; still smooth as butter though.
 
Last edited:
Gadt said:
Grease the pivot
Click to expand...
The knife is properly lubed with flouro grease

Haze said:
If you back the pivot out the blade doesn't loosen at all ? :confused:.....When you say "stiff" how would you describe that ?

Is it being slowed by tension or are you feeling some other resistance ? To word it differently, is it like waving your arm through water or rubbing your hand along the wall ? :D
Click to expand...

If I loosen it anymore then it is, the blade is off center and has blade play. It feels like it is being slowed by tension, I have had that feeling on other knives before and usually a small drop of flouro grease on the detent fixes it.
 
This is just the difference between the two knives having a different pivot set up. The 21s blade with the bushing is pretty much free swinging, the umnumzaan is just as smooth but that extra tension is always there. :)
 
I don't want to read things into the OP that aren't there, but even a properly set up Umnu is going to feel quite different (or at least they do to me) than a Sebenza because of the relative position of the lug and the pivot. The Umnu is always going to require a different motion that (to me) feels like it needs more force. YMMV.
 
JNewell said:
I don't want to read things into the OP that aren't there, but even a properly set up Umnu is going to feel quite different (or at least they do to me) than a Sebenza because of the relative position of the lug and the pivot. The Umnu is always going to require a different motion that (to me) feels like it needs more force. YMMV.
Click to expand...
That is my experience as well.
 
And you probably already know this, but tiny adjustments of the pivot make big differences in the operation of opening. If the difference between having the blade off center and being too stiff is 1/2 of a turn then you can try messing around with 1/16th of a turn increments until it feels right within that 1/2, if that makes any sense. I am always surprised how much difference those 1/16th or 1/32nd adjustments make.
 
Kind of funny about the adjustment. My last Umnum was pretty stiff and I could never get it adjusted to my liking. That's a small part of the reason I got rid of it and went to carrying a 21 full time. I have another one waiting for me when I get home to give it another try though. We'll see how it works out. I took it in trade so I will prob just flip it toward another 21 ... thinking a UG design.
 
You must log in or register to reply here.
Back
Top