Umnum thumb

S

shooterpunk

Joined
Mar 22, 2005
Messages
521
Hey guys, I bought an Unmumzaan last week and since then I've had a pretty sore thumb. Am I the only one that has a hard time disengaging the lock bar? I feel like it should be a little more rounded and have a little more of a cutout so you can get a little more purchase on it. Oh well, I love the knife though, it's great! Any tips for my sore thumb? Thanks guys!
 
I definitely experienced the same thing with my production Umnum; it just needs to be broken in. I thought they needed to change the lockbar, but once you break it in you'll realize it's perfect.
 
I picked one up new from my local brick and mortar store about 2 weeks ago. It was born mid July 2010. It is smooth as butter and very easy for me to disengage the lock. There is a small teardrop shaped cutout in the lock (blade side) that my thumb catches that helps provide grip when I disengage. I can't post pics - at work right now - does yours have that?

I've never handled one until now - maybe this is something new that Chris is doing in newer models to help with the issue?
 
Congratulations on your new knife! Disengaging the framelock on the Umnum is not as comfortable as the Sebenza. I've had the same problem too but no biggie for me. Just keep going 'till you develop callus on your thumb, then it won't be sore anymore.
 
shooterpunk said:
Mine was born July 15, 2010 and has that little teardrop cutout, but that is what hurts my thumb.
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Sorry to hear that. I will say that the ceramic ball makes disengaging the lock much easier than metal to metal or metal to titanium contact.

The toughest I ever had (and the only one to ever make my thumb hurt to the point where I had to give up opening the knife for a while) was a brand new Strider SnG. It took several hundred openings before that one got smooth.

Hopefully yours will break in nicely and become less of an effort to open.
 
Ya I had a Strider SNG as well and it took a little while to break in but I never got a sore thumb from it. Oh well, Im sure it'll break in soon and become easier. Thanks for the comments guys
 
I noticed a bit of an issue at first, but I think it's mostly technique. The small bit that's milled out I really like though.
 
I do think the lock bar could use a little more purchase area for my thumb. With that said, mine has gotten a lot easier to open over time. When stiff, I would sometimes use my index finger to disengage the lock which was easier for me. Also, I have found it easier to use either my thumb or index finger farther back on the lock bar than where the little divot is.
 
I've noticed that its not real smooth opening now either, feels gritty. I dont have the take down tool so i squeezed in some breakfree (as I have with all my knives) but it doesnt seem to help it much.
 
The sebenza and umnumzaan open and close a little differently. Once your umnumzaan breaks in a little, you will be opening it like a automatic. Just takes some getting used to is all. Your thumb will get used to it too and toughen up a bit.
 
shooterpunk said:
I've noticed that its not real smooth opening now either, feels gritty. I dont have the take down tool so i squeezed in some breakfree (as I have with all my knives) but it doesnt seem to help it much.
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Because of the Very Tight CRK Tolerances, I have found often that lube will not work its way in like it would on a cheaper knife.

When I first got my zaan, I did not have the take down tool either and took it apart. I got 2 round toothpicks and cut the point off until it fit into the holes of the pivot. Place them in the 2 holes, hold the other side of the pivot and it will unscrew easily. When I put it back together, I put a very small piece of teflon tape on and it held it in place very nicely. I did get the takedown tool eventually, but by doing it this way, its not really a necessity.
 
shooterpunk said:
I've noticed that its not real smooth opening now either, feels gritty. I dont have the take down tool so i squeezed in some breakfree (as I have with all my knives) but it doesnt seem to help it much.
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As mentioned the tolerances will probably prevent anything from getting in there. Toothpicks are one way, the tool is rather inexpensive and very useful if you have to take it down.
 
I tried with mine for 2 months prior to selling it, had a good blister on my thumb, High tolerances seem to have their downsides in some designs.
 
I have a feeling I may end up trying to trade this for a small micarta sebenza like I had before. Oh well I guess.
 
The umnum also gave my thumb a beating. I wonder why they didn't make the lock bar rounded like on the Sebenza. Unlocking my Sebenza feels smooth as a baby's butt.
 
shooterpunk said:
I have a feeling I may end up trying to trade this for a small micarta sebenza like I had before. Oh well I guess.
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This is what is so great about knife collecting. Each person's experience is unique. I actually feel the opposite of this. My Umnumzaan and Mnandi have pushed my small Sebenza back to the safe and nearly to the auction block. When not wearing light dress clothing the Umnumzaan is my absolute favorite.
 
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