Who needs dual thumb studs?

alpine0000 · Mar 4, 2011

I'm just messing around tonight and bored. But if you guys remember, when I got my sebenza, I was having big problems with it (see this thread: http://www.bladeforums.com/forums/showthread.php?t=779879 ).

After bending the lockbar backwards to loosen the ridiculous pressure on the blade a bit (yikes!), and then practicing with it a bunch, I can finally (easily) open it one-handed with either hand (single thumb studs!).

Now, I know I know... I don't usually 'flick' it open like this. I'm just doing it here to show how easily I can open it now. Usually I just glide it out with my right hand

http://www.youtube.com/watch?v=cRecSoibdp8

ZippoThisKnifeThat · Mar 4, 2011

Wow never seen that done before with a Sebbie!

Glad it's to your liking now.

cmichael · Mar 4, 2011

WOW..I wish mine open like that, But I just got it last week.

kadinh · Mar 4, 2011

the way you open it left handed is how i open my spyderco manix 2 with my right hand. with my middle finger, but no wrist flicking, just a quick flick of the finger and it glides open.

cziv · Mar 4, 2011

I'm sure your lockbar is way over to the side at about 110% lockup after that. I have come near to shaving the epidermal layer of skin of my thumb many times but I'm getting it opened finally with less trouble.

The trick for my big fingers is to keep them off the lockbar while at the same time staying right on the blade at the bottom of the thumbstud with my thumb. I always have to think of every bit of the opening or it won't open, thumb slides off over the top, thumb slides off and almost slices thumb. What a pita!

The d*amn hardest folder I've ever owned in my life to deploy and other than that so beautiful.

ForestRoamer · Mar 4, 2011

My Small Sebenza that I have had for 2 years opens nearly as fast as that, but my newer Sebs are slower. I guess they require a break in period, but you don't have the patience for that haha.

charlOOsi · Mar 4, 2011

Work out that left middle finger and you'll be able to flick it open without the wrist. It's how I use all my knives ambidextrously. Even my Umnumzaan.

alpine0000 · Mar 4, 2011

cziv said:
I'm sure your lockbar is way over to the side at about 110% lockup after that.

My lockbar only comes about 40% over the blade, regardless of how hard i flick it. TBH, I dont flick it hard at all. Just enough to get it open.

cziv · Mar 4, 2011

alpine0000 said:
My lockbar only comes about 40% over the blade, regardless of how hard i flick it. TBH, I dont flick it hard at all. Just enough to get it open.

I misundertood your post. Of course, bending the lockbar outward would give an earlier lockup. My bad.

giant1 · Mar 4, 2011

That's pretty quick opening :thumbup:

I have carried the same large sebbie for at least the last two years and would say that mine deploys nearly as quick, but I have never adjusted the lock bar. I'd say mine is broken now

I like how you can do it both sides, I definitely cannot do that.

alpine0000 · Mar 4, 2011

cziv said:
I misundertood your post. Of course, bending the lockbar outward would give an earlier lockup. My bad.

No. My lockup is the same. Bending it outwards a bit just results in less pressure on the blade when opening/closing it. It still locks up exactly the same. It's not a permanent bend or anything.

arjung · Mar 4, 2011

strange my sebenza I got in July can do that without any modifications. It did a little breaking in but that was in.

snowreaper1 · Mar 4, 2011

The day after I got my brand new tanto I took it apart and lubed it up with
the CRK grease. Im able to flick open with no wrist movement at all. And its
a really fast deployment. Its just sometimes inconsistent with a for sure
deployment because my thumb sometimes slips on the small pointed
thumbstud.

alpine0000 · Mar 5, 2011

arjung said:
strange my sebenza I got in July can do that without any modifications. It did a little breaking in but that was in.

I am convinced that the tension is not the same on each lockbar that leaves CRK. Some people say theirs is nice and smooth, and some people say its very tight. I could barely move my blade, even with two hands. One hand was nearly impossible.

wintersix · Mar 5, 2011

I got a large sebenza recently and I have a hell of a time opening it. Seems to take a lot of force on the stud to get it moving, once it does it is like glass.

I dont know what the issue is, I have actually had to use two hands to get it started a couple times.

The umnum that I got at the same time, I dont have that issue with, seems like there is more space for my thumb to engage the thumbstud, also on the Sebenza the thumb stud seems really recessed and pointy so it makes for a very narrow window when trying to engage. I am going to try and open and close it as much as possible and break it in ( break me in) and see if it gets better, other wise the Seb is getting relegated to the lunch box.

On the other hand the Umnumzaan is one hell of a knife, I dont even know what else to say, other than I wish they had more customization options like the Seb.

alpine0000 · Mar 5, 2011

wintersix said:
I got a large sebenza recently and I have a hell of a time opening it. Seems to take a lot of force on the stud to get it moving, once it does it is like glass.

I dont know what the issue is, I have actually had to use two hands to get it started a couple times.

The issue is that the lockbar is applying a lot of force against the blade, and the little ball on the lockbar sits in the hole in the blade. All the force from the lockbar makes it hard to get the ball out of the hole in the blade and get the blade moving. bending the lock bar back about an inch for a few seconds will make it so that there isnt as much tension on the blade, hence making it easier to open. It doesnt take too much, and doing that doesnt effect the lockup at all. mine is perfect now, but when i first got it, it was HORRIBLE. i wanted to return the knife.

Its easier now, but still my hardest knife to engage. To me, its the most difficult and worst engaging knife I have ever handled, but it is still good quality overall

In my opinion, if they re-designed the thumbstuds and better controlled the lockbar pressure so some of the knives leaving the factory arent painful to open, then the knife would be a perfect 100%. Right now, i give it like a 95%.

Still love the knife though.

ThumperACC · Mar 6, 2011

wintersix said:
I got a large sebenza recently and I have a hell of a time opening it. Seems to take a lot of force on the stud to get it moving, once it does it is like glass.

I dont know what the issue is, I have actually had to use two hands to get it started a couple times.

.

I had the same issue with my first sebenza. There were 2 issues. The first was me. I was unknowingly placing my middle finger on the lock bar when I was trying to open the knife. The harder I tried to open it the more I was preventing myself from opening it.

The second issue was just a breakin required. I (using 2 hands and my thumbnail instead of my thumb) popped the blade in and out of its detent (closed it, opened a 1/4", closed again, opened 1/4", repeat) 1,000 times one day and the detent relaxed just enough to make it reasonable to open but with still a strong detent to keep it closed. Since I carry in waistband, keeping it closed is very important to me.

Good luck and enjoy,
ThumperACC

cziv · Mar 6, 2011

alpine0000 said:
The issue is that the lockbar is applying a lot of force against the blade, and the little ball on the lockbar sits in the hole in the blade. All the force from the lockbar makes it hard to get the ball out of the hole in the blade and get the blade moving. bending the lock bar back about an inch for a few seconds will make it so that there isnt as much tension on the blade, hence making it easier to open. It doesnt take too much, and doing that doesnt effect the lockup at all. mine is perfect now, but when i first got it, it was HORRIBLE. i wanted to return the knife.

Its easier now, but still my hardest knife to engage. To me, its the most difficult and worst engaging knife I have ever handled, but it is still good quality overall In my opinion, if they re-designed the thumbstuds and better controlled the lockbar pressure so some of the knives leaving the factory arent painful to open, then the knife would be a perfect 100%. Right now, i give it like a 95%.

Still love the knife though.

I've watched the video that was recommended in another thread on the thumbstud and how to open the Sebenza properly http://www.youtube.com/watch?v=HcXu6dVRCOE - horse hockey! Mine is like yours. You could hit the volcano lug with a punch and a ball peen hammer and the blade wouldn't start (like described in this video).

I have to use my thumbnail to start the blade and try to catch up with my thumb after it pops out, before my thumb falls into the blade. I've nearly taken the thumb skin off a few times by trying to deploy my large 21.

This dude has to have a smooth detent or very tiny thumbs. I can't even get my thumb into the area he illustrates. I believe it will break loose one of these days, as it's only been a few weeks and a couple hundred openings so far. I have to hold my large Sebenza with only the tips of my fingers on the top 1/2 of the handle and dig the blade out with my thumbnail, and then quickly catch up to the described area & into the proper placement quickly to complete the sweeping motion that completes the movement.

I can open my CS Rajah 1 easier and faster with my thumb than this knife. I'm not kidding a bit either. I've never put so much thought into opening a folder in my life - mentally going through the sequence before even trying.

My 1st large 21 came right out of the box like butter. Not this stubborn one though. It will lose in the end and become part of my rotation, but not until it will open w/o a lot of thought.

Fooj · Mar 7, 2011

cziv said:
I've watched the video that was recommended in another thread on the thumbstud and how to open the Sebenza properly http://www.youtube.com/watch?v=HcXu6dVRCOE

My experience has been like you see in the video. The two things that have made it easy for me to open every Sebenza I've handled (which is a shamefully large number . . .

) is:

Push on the side of the thumbstud (cone) like you're trying to slide the thumbstud across the surface of the blade, NOT pressing the thumbstud into the blade, and
Push in the direction of the pivot, NOT perpendicular to the handle.

I don't like the thought of reducing the lockbar bias for three reasons:

When closed, the lockbar pressing the ball into the detent holds the blade secure -- you don't want the blade coming open in your pocket
With the knife opened, you want the lockbar to snap into place behind the blade with as much force as CRK adjusts at the factory, to insure strong engagement
Undue messing around with the lockbar could weaken it at the scallops

If you've got problems opening your knife, I'd encourage you to give CRK a call, and let them help you with a solution that keeps you safe, and the knife from damage.

cziv · Mar 7, 2011

Fooj said:
My experience has been like you see in the video. The two things that have made it easy for me to open every Sebenza I've handled (which is a shamefully large number . . . ) is:

Push on the side of the thumbstud (cone) like you're trying to slide the thumbstud across the surface of the blade, NOT pressing the thumbstud into the blade, and

Push in the direction of the pivot, NOT perpendicular to the handle.

I don't like the thought of reducing the lockbar bias for three reasons:

When closed, the lockbar pressing the ball into the detent holds the blade secure -- you don't want the blade coming open in your pocket

With the knife opened, you want the lockbar to snap into place behind the blade with as much force as CRK adjusts at the factory, to insure strong engagement

Undue messing around with the lockbar could weaken it at the scallops

If you've got problems opening your knife, I'd encourage you to give CRK a call, and let them help you with a solution that keeps you safe, and the knife from damage.

Thanks Fooj! Good illustration. The regular allows a lot more room to access the thumbstud than the tiny cutout of the 21. I learned for your post (Sebenza is between my arms as I type) that when exerting almost zero downward pressure toward the blade, it come out much smoother and easier.

Mine's breaking in a little more every day. Last night I opened it for about an hour or more using various directions and thumb positions. It's feeling smoother this morning. I'll probably be carrying it in another few days to a week of breaking in. It will be the day when I pick it up and open it without having to remember all of these instructions.

I just reached out and opened it, and it went pretty smooth. :thumbup:

That is one beautiful graphic "Okinawa karate" my style man! http://teicon.blogspot.com/