CHRIS REEVE: Thumb- Numb- Zaan

Discussion in 'General Knife Discussion' started by Dave Agazzi, Feb 28, 2021.

  1. Dave Agazzi

    Dave Agazzi

    Feb 28, 2021
    I own and use Chris Reeve knives. I have done so for about 12 years. Recently I ordered a large Umnumzaan and tried over a week to open it easily, and many other ways too. I don't think opening a folder should require instructions or techniques. I get the fact it opens differently. I finally gave up and sent it back. Great knife with a design flaw. Thumb stud is hard to contact with the thumb as its too close to the scale. Also, thumb stud is small and shaped so it hurts to push, straight up as they specify and not out in a arc. I was told to hold the knife so as not to put pressure on the lock bar. Good luck on that one. It can be done while holding the knife in a very awkward way.When doing so it becomes easy to drop the knife as you are not holding on to much. Love Chris Reeve knives, just not the Thumb- Numb- Zaan!
    Alsharif likes this.


    Aug 7, 2010
    I loved my Startac Umnum but that's exactly why I traded it off. I didn't like how it opened.
  3. Alberta Ed

    Alberta Ed

    Jun 29, 1999
    I generally use two hands to open my 21; the small thumb stud is a bit awkward though still usable. OTOH, a larger thumb stud would be obtrusive, so I can live with it. It's still a masterpiece of design.
    Dave Agazzi likes this.
  4. jumpstat


    Mar 9, 2007
    I love my Umnumzaan and the way it is being deployed. Indeed one need some training time to be able to deploy it properly. Once you get the hang of it, its very satisfying to use.
  5. hhmoore

    hhmoore Gold Member Gold Member

    Feb 7, 2014
    How many times did you drop it?
  6. Ajack60

    Ajack60 Platinum Member Platinum Member

    Apr 21, 2013
    The Umnumzaan isn't for everyone. I find it easier to open than some 21's.
    Maybe the lock bar tension needs adjusting, maybe the pivot can be loosened until it's broken in. Maybe it needs to be taken apart and thoroughly cleaned.
    Just because it's not meant for everyone doesn't mean it's a difficult knife to open. Sometimes learning little techniques to open/close a knife make it more enjoyable.
    highestpoint and flipe8 like this.
  7. Terry M.

    Terry M. Platinum Member Platinum Member

    Feb 5, 2006
    Had trouble opening one when I got it too. I’d tell you it gets easier but you already sent it back so.........
  8. Makael

    Makael Books temporarily closed on sheath orders. Knifemaker / Craftsman / Service Provider

    Oct 17, 2015
    Mine was easy once you stop trying to push the stud out and learn to push up instead. Not very difficult.
  9. Makael

    Makael Books temporarily closed on sheath orders. Knifemaker / Craftsman / Service Provider

    Oct 17, 2015
    Should post your issue in the CRK area.
  10. Wolverine666

    Wolverine666 Gold Member Gold Member

    Dec 7, 2009
    I saw someone on here do a custom Spydie-style hole on a Sebenza and it looked beautiful. Perhaps that’s what would benefit some people on the Umnumzaan.
    JDRanger likes this.
  11. goldie


    Feb 18, 2000
    I wound up selling mine for similar reasons. Its bad enough that its so close to the scale, but it being so polished doesnt help either. i think it should be knurled so you can get a better purchase on it. Always had misfires trying to open which really annoyed me. Ive also noticed that over time those o rings wear and need replacing.It makes a difference when new ones are installed.
    Dave Agazzi likes this.
  12. Alsharif

    Alsharif Gold Member Gold Member

    Jan 8, 2018
    90s heritage brand stuck in the past.
    K.O.D. and scottyj like this.
  13. braillediver

    braillediver Gold Member Gold Member

    Oct 6, 2007
    Love the knife but resold 3 or 4 since I never got the hang of easily opening it.
  14. Mako109

    Mako109 Gold Member Gold Member

    Dec 17, 2008
    Mine was stiff as hell when new and I almost returned it. Adjusted the pivot, disassembled and polished the washers, tried different lubricants, and it was still Very unlike my Hinderers, Koenigs and almost every other knife of that caliber where the blade flies out on deployment and drops shut straight out of the box.

    I decided to give it a chance and kept it my desk where I would fidget with it while working. About 3-4 months later it broke in, or I finally developed a feel for it, but probably a combination of the two. Now the blade can be slow rolled smoothly or thumb flicked out with authority. The pivot is quite tunable too. Just a smidge to the right or left will change the action, so I put a tiny bit of blue Loctite to hold it firmly where I like.

    The Umnum and Inkosi were a lesson in patience and perseverance, but now they have become two of my favorite knives.

    Edit to add: I do agree with the OP as my thumb was pretty torn up during the break in period.
    Last edited: Feb 28, 2021
    kobold likes this.
  15. Hackenslash

    Hackenslash Don't feed the Trolls Platinum Member

    Jul 25, 2014
    The Zaan has perhaps a steeper learning curve than many other knives, but it’s definitely do-able with a nice hydraulic action. You just have to stick with it and develop some muscle memory. I guess not much point for the OP as they already punted.
  16. Kmikaz3

    Kmikaz3 Gold Member Gold Member Basic Member

    Aug 28, 2019
    I find it really easy to open with factory tightening. If your thumb slides along the scale chamfer or ramp and push it upwards, the blade will comes along with your thumb motion instead of trying to push to the side.


    With that said, you can even flick the blade out by building pressure and flick it upwards

  17. Silvanus

    Silvanus Gold Member Gold Member

    May 17, 2012
    I’ve seen more and more posts that are similar to this one popping up lately than I ever have before. I myself have had a similar issue with a Sebenza 31 which uses the same lock interface as the Zaan. I’m wondering if some specs have been tweaked, the detent strength has been increased, or if it’s another factor like how their stop pins on the Sebenza 31’s are rumored to be made differently leading to tolerance issues?

    I feel that this is a recent problem as I owned an Umnumzaan and a Sebenza 25 that were both made in 2012 or so and I remember a much smoother action and a more appropriate detent strength.
  18. mongomondo

    mongomondo SUPPRESSING FIRE

    Sep 17, 2006
    The last umnum I had was made in 2015 and it was easy to open. Closing on the other hand was torture because the lockbar was so sharp.
  19. ron finkbeiner jr

    ron finkbeiner jr Gold Member Gold Member

    Jan 6, 2012
    This is why I like Spyderco.
  20. jjg6319


    Dec 19, 2011
    Post 15 nailed it with the videos. You have to push along the scale and NOT perpendicular to the thumb stud.
    marrenmiller and Peakbagger46 like this.
  21. goldie


    Feb 18, 2000
    I think if you have to use a certain method and process to open a knife, that knife is not for me.
    JBradley500 and Triton like this.

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