One-hand opener ergonomics

[johnniet]

I am posting here because I do not own enough knives to know the answer already.
With many knives designed as one-handers, it is difficult to move my thumb all the way from the closed position to the open position. This leaves two alternatives:
(1) open it partway and then "flick" it the rest
(2) twist your hand around a bit, maybe awkwardly, maybe painfully, so your thumb can reach the closed position.

I have had such problems, so far, with an Ascent 820, a Jot Singh Khalsa, and now an EDI Genesis.
NO such problems with my Cricket and Dragonfly.
Question: is the difference just size, or design? For example, I think the Genesis (with the 3.9" blade) *would* be fine if not for the widening of the handle at the top. Presumably this is meant as a guard, but it gets in the way of my thumb...

Now -- will I find this to be less true if I stick to Spydercos? (I assume JSK is an exception, as a collaboration model with a very unusual design.) What steps do most of you use in opening your Enduras, Wegners, Calypsos and Natives? Is there anything in the way of the smooth motion of the thumb, or do you have to "flick" at the end?

 

[Ferret]

Never had this problem myself but maybe that's 'cause I'm a lefty opening RH knives

 

[Brian_Turner]

What you're really talking about are differences in the opening arc, and these are going to differ with each knife. Additionally, it will have something to do with your thumb.

I think that Spyders will have an "edge" on most other knives in this area, because a hole allows the thumb to be in a variable position during the opening, as opposed to a stud, which requires every user's thumb to sit in an identical position, ie. the tip of the stud.

With the hole, you can dig your thumb deeper in, or just use the tip of the thumb. As the blade moves through the opening arc, your thumb will "automatically" adjust position to keep your position comfortable.

Of course, the placement of the hole and it's size will have something to do with comfort as well, but I think that a hole "in the general vicinity" will be more comfortable than a stud placed in the same spot.

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AKTI Member #A000832

"A man's got to know his limitations." - Dirty Harry

 

[edrozen]

With all due respect, you should try posting this in general discussion. Now that I've got that overwith, I can say I think you probably need to try with a smaller knife. The BM and Jot S. Khalsa are both good, but you're just going to need more practice. I have a few other ideas, some of them are the spyderco, but I have a few other ones that aren't so I'm not going to post them here. I have a Spyd. Rescue that I use a lot, and it is easy to open. good luck

 

[David Rock]

johnniet:

Are you positioning the knife handle diagonally across your palm? Try orienting the handle perpendicularly across your fingers, with your finger tips curved around and braced agaist the edge of the clip. This will put your thumb at a better angle to complete the entire arc. Of course you'll have to adjust your grip a bit once the blade is open. Works for me.

For quick draws, I generally don't try to complete the arc. I use the hole or stud to pop the blade into motion with a bit of a wrist flick to assist.

David Rock



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AKTI Member # A000846
Stop when you get to bone.

 

[Sal Glesser]

Johnniet - "In house" designs favor ergonomics over appearance. We have developed a number of formulas and sizes that we work from. 20 years of making "one handers".

Collaboration designs are more in the hands of the designer. Their designs are usually prettier.

For your own use, try putting the knife farther down in your hand, so the pivot pin is just above the index finger knuckle. Wedge the back of the handle in the base of your fingers and grab the clip with the remaining fingers. This gives the thumb a larger arc capability.

sal

 

[johnniet]

Thanks for the advice guys!

Brian -- I think you are right on target about holes and studs.

Ed -- the reason I posted in this forum was because Spyders are (famously) designed a little bit differently from most folding knives, partly for this reason. If I had directly asked "are spydies better", "does the hole make opening easier", etc., I was afraid I would get 200 posts saying "Yeah, Spydercos rock" without the insights that I have gotten here.

David and Sal -- thanks for the tip on holding the back against the base of the fingers. It works very well--even on thumb stud knives. (Hm...maybe I don't really need that hole anymore...yeah right) ;^)
It's good to hear that, as I suspected, the in-house designs have already had a lot of thought on this put into them. Sounds like time to put a few more of those on my wish list...