"Quiet" Opening/Closing of Umnumzaan?

MostMenAreRuthless

MostMenAreRuthless

Joined
Sep 27, 2011
Messages
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CRK Brothers and Sisters,


I am fairly new with the Umnumzaan and I have read several posts regarding how quiet it is to open and close due to the rubber o-rings. I am concerned that mine may not be outfitted with the correct size of o-ring (they are not stock) because upon opening/closing there is a gentle, but still audible "clack". If I apply very little pressure on the opening or closing it is soft, but with any pressure it is a clack. Any thoughts?



Shaun
 
As long as there is some sort of rubber interfacing with Ti handle I think you should be ok. I know the aftermarket ones don't last as long as the polyurethane but there cheap. I think I heard So-Lo say there # 60 from Home Depot or at least thats what he uses. Mine are getting a little looser than new so I might give Heather a call and se if I can order some.
With my Umnum I've noticed its much quieter than my Sebenza 21's & 25, but it still does make a little noise, very quiet though if you open it slow and a bit louder when opened quicker. My 25 is louder than my 21's also. Maybe try new ones from CRK and see if that helps.
 
I've heard people say there not necessary and the knife can go without just fine, but I like the quite opening myself. It could depend upon lockbar tension on the also. If yours is very strong and snaps over really quick to 80% that might be making some noise also, my 25 is very strong and snaps to 75% with a nice satisfying clack.
 
I'm playing with my 'Zaan right now, with stock o-rings it is definitely not completely silent. It's quieter than other knives by a long shot, but not dead silent. I do suggest picking up some of the polyurethane o-rings as I've tried some aftermarket o-rings on her to give her some flare and they've all started to get loose after not-too-long. The stock o-rings fit nice and snug making them function better and look better. I find that aftermarket o-rings will start to loosten and shift around, it's not pretty and not as cushiony.
 
jsd--thanks for the input.

I just sent an email to Heather to see if the ones CRK uses can be bought at a hardware store or if I have to order them direct. I will post when I hear back.
 
I just put o rings from online on my 2011 Zaan and it def clicks when it opens.m the only way I can get silent opening and closing is to ease the lock bar when it opens and shuts. Sounds like your Zaan is perfectly normal :)

I prefer a nice click when it opens! Just my 2 cents
 
Over time the o rings do degrade. The first pair on mine started to fray and started to sort of dry rot. I emailed CRK about it and they sent me four new ones within just a few days.
 
Honestly, the CRK rings do flatten out or degrade or something like that. I bought a package of O-rings that someone here recommended from Amazon and they have held up perfectly so far - and yes, like several of you, I totally love the silence of the Umnu when the rings are doing their job. :thumbup:
 
I carried my tanto Umnum for over two years as my edc, needed new o rings for a long time before I replaced them because the originals kinda bagged out and became a bit loose. It never caused a problem and the knife absolutely does not need them. I did however very much enjoy the quiter opening and closing of the knife after I put some new one son from the hardware store, for some reason I find the smoothness of the ceramic ball interface and the quiet operation of that knife very satisfying.

It sounds like yours is just fine, try turning the rings a little to get some fresh rubber hitting the Ti, it's a short term fix but it may help the clack a bit until you get another set.
 
Mine has always made the loud "clack" as you mentioned. Mine was even sent to CRK and Chris himself worked on it for me and I even spoke to him over the phone about it. Nothing to worry about.
 
Mine was very quiet when it was new. Surprisingly actually. But after a few months of use it developed that "clack" sound. Its Normal I'd say. Even after I replaced my worn out gummy Orings with new CRK replacements it still wasn't as quiet like when it was new.
 
The physics of quiet opening and closing is quite complex. The ring has to compress at a slow enough rate that it damps the noise but allows full opening and closing. Otherwise the blade would not open fully or have a bit of play. There's likely some ring made of unobtainium that would work perfectly......
 
When I had an Umnumzaan the rings would allow a quiet opening the first time or two after rolling the "o" ring in my fingers but after that they would flatten and would have a muffled clank sound on opening.
 
I had the same experience. Someone here suggested some O-rings from Amazon that have turned out to be almost infinitely more durable as far as not flattening out, and therefore maintaining silent opening, goes.
 
Mine is still quiet to this day. It may depend on the condition of the rings as to whether they are dried out or misshaped.
 
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