Sebenza's actually not that smooth?

J

Jadis

Joined
Oct 2, 1998
Messages
438
I've noticed on every Sebenza (that I've owned and handled at shows) that, really, they are not that smooth. Be it brand new, or broken-in and relubed and everything, I have definitely handled folders that are smooth (a lot smoother), and I mean plain old production folders, not customs. The action on the Sebenza's seem to feel tight and stiff. Particularly, when you open/close the blade SLOWLY, there is a stop-and-go action. Have any of you experienced this and/or agree with my experiences?
 
The initial stop and go action (i.e. as it just opens) is probably due to four factors:

1. Ball/detent
2. Static vs dynamic friction
3. Hand/thumb mechanics
4. Edit - Thumb stud placement and liner/scale curve/relief

I get the initial stop and go action on all my knives (worse for some than others). The size of your hand will certainly influence how easily you can open a knife and not every knife will suit.

I have read here that many forum users have had great success improving their Sebenza action after disassembly, clean, relube, and reassembly. Haven't tried it yet.

My large Sebenza action is smooth (as butter) and firm (not tight). I have several knives that open 'more freely' so they appear more smooth but they are not (e.g. Benchmade, Microtech). My Strider SnG is quite smooth but also firmer than my large Sebbie. My Strider AR is also quite smooth but also more freely opening than the Sebbie (due to the bulk of the blade, positioning of the stud, and the liner relief/curve I can get excellent purchase on the blade and open it real fast).

IMHO the true test of a knife's smoothness is slow opening. A smooth knife will only have the stop and go jerky action at the start of opening. After that it should be smooth no matter how slow you go. I have tried this with Benchmade and Microtech and get jerky motion all the way through but to varying degrees. On my Sebbie it is smooth sailing as it is on my Striders. The differences are of course typically small but occasionally noticeable.

Cheers.
 
I checked a number of mine after reading the above post. Some are a little hard to start but they seem to be smooth through the range. My Mnandi was a little rough at first but I took it apart, cleaned and lubed it, carefully put it back together and now it seems fine. Jadis if you still have one that you don't think is smooth, send it back to CRK and have then look at it. Sorry to hear that your experience with Sebenzas leaves you less than satisfied.:confused: :cool: :p ;)
 
Jadis,
A Sebenza might indeed not be as smooth as other knives. I once handled a Benchmade Mini-Griptilian and that was the smoothes knife I ever handled.
But, the good thing about a Sebenza is, when you take it apart and put it back together, you get exactly the same action. On 99% of the other knives, you will have to carefully set the tension on the pivot with the pivot screw, and fasten it with loc-tite or other stuff. It also might loosen over time. This will not happen with the Sebenza. You can screw the pivot down tight and still have the same smooth action.

Ted
 
I've owned over 14 Sebbies and have only experienced one that was stiff. Even after relubing and initial 30-day break-in. But, after 3 - 4 months of use. . .it became buttery.

I think that they type of washers used (in all knives) will have a play on stiffness/how smooth a knife is. Knives with Teflon washers are typically extremely smooth out of the box ! Where as metal washers (i.e., bronze) shows signs of jerkiness if they have a patina on them.



By the way. . .very well put monanza !
 
my lg stars and stripes is smooth as smooth comes but my sm unique w/ damascus is not very smooth at all, the smoothest knife i own is a brend da from cutter knife and tool, awesome knife every1 should own imo
 
Both of my small Sebenzas and my Umfaan open very smoothly. No, they are not the fastest, but none of them have opened on me by accident either.

Paul
 
Knives with the crappy nylon washers are gonna be smoother. So yeah, the CRKT might be smoother upon opening. Sebenzas DEFINATELY get smoother with age. My EDC of 2 years is WAY WAY WAY WAY more "smooth" or slick opening and closing. It is just due to the washers smoothing down over time... there is just less resistance. Personally, I like a little resistance. I wish sebs were HARDER to open. There really is NO company that makes knives to the tolerances that CRK does. If it's been said, it's been said 1,000 times: You have to really use the thing to gain actual apprecation... WARNING... you may WANT to ding up your knife after getting it in the muck enough! I guess if one still can't understand the quality involved in a Sebenza, You don't deserve eachother! Sell it and buy a couble of "smoother" knives. Oh and make sure they have a bunch of plastic on them... that way the knife will corrode to dust in 10 years and you'll have learned a lesson the hard way... Of you could just visit the Smithsonian, and wee what they are having to do to "artifacts" made with plastic... space suits, army stuff, dolls, apliances, everything is deteriorating. Titanium, Stainless Steel, Bronze... There ain't much to go wrong. Beware of nylon washers.
 
IME, new sebenzas are a smooth but a little stiff, but after sufficient carry, maybe a month or so, they will break in and become less stiff.

That's the cool part about buying a used sebbie, they already broken in!
 
My large Sebenza action is smooth (as butter) and firm (not tight). I have several knives that open 'more freely' so they appear more smooth but they are not (e.g. Benchmade, Microtech). My Strider SnG is quite smooth but also firmer than my large Sebbie. My Strider AR is also quite smooth but also more freely opening than the Sebbie (due to the bulk of the blade, positioning of the stud, and the liner relief/curve I can get excellent purchase on the blade and open it real fast).
Click to expand...

Let's try to define smooth here guys. Can a folder's action be "smooth" AND not "freely opening"? What do you mean precisely by these terms? If you have ever handled a folder with ball bearings like a Larry Chew or a TiNives, those ARE what I would call incredibly smooth (very little resistant in the action, as if on air).

I'm sure many of you have experienced the looser action on plain jane production folders (like say, an AFCK) wherein the action becomes particularly more free moving if you signficantly loosen the pivot screw, and becomes less so if you tighten the screw. Clearly, this is due to less frictional force because the handle slabs aren't clamping down on the pivot assembly as much. I would call the looser, more freely flowing action "smooth" and the tighter action "not smooth".

Shouldn't a high-end folder, such as a Sebenza, have action as freely moving as when you overly loosen a plain jane production folder, yet still be completely free of play? It seems to me that Sebenzas' pivot assemblies are "clamped" too tightly.

If the Sebenza is supposed to have very high tolerances, shouldn't the assembly be made in such a way that the parts fit exactly together, with no play, yet don't need to have (barely) any force to hold it together? It would seem to me such a situation would produce, what I would call, a very smooth action.

To illustrate what I mean, think of the blade tang, bushing, washers, and handle slabs as a sandwhich of flat metal plates. If these metal plates surfaces are TRUE (i.e. precisely flat) and mate within high tolerances, then if you were to stack them on top of each other, there should be NO space between them (i.e. no play). You wouldn't need to push down on them (hardly) with your hand (i.e. clamp them with a pivot screw very hard).

But this is not my experience with (several) Sebenzas. If you screw down the pivot EXACTLY to the point where there is no play (i.e. you are now exerting the minimum clamping force required), then the action is still NOT what I would call free flowing, compared to other folders I have handled (that had NO play). Clearly, the pivot assembly (blade, washers, et al) together are slightly too "thick" for the space between the handle slabs.

Anyway, that's my take on things.
 
Jadis,

If you screw down the pivot EXACTLY to the point where there is no play
Click to expand...

With a Sebenza, there is (should be) no 'EXACTLY to the point where there is no play'.

Either the pivot screw is totally removed when dis-assembled, or it is screwed down as tight as you can when assembled.

If you're in a situation where you can't screw the pivot-screw down tight, it's probably assemblied wrong (a crimped washer).
The pivot screw on a Sebenza should always be as tight as you can.

And, I guess there needs to be a little room in between the slabs and the bushing/washers/blade, because of a tiny film of lube.

Ted
 
Jadis,
After reading your post again, I sense you might have tried to make a different point and you already knew about how the pivot works on a Sebenza. If so, disregard my reply

Ted
 
Good point on the definitions.

Here's mine.

By smooth I mean that when the blade opens there is no crunch from grit and no "grabbing" by metal against metal friction.

By stiff I mean that the blade does not swing freely ( from gravity for instance) and needs to pushed steadily open.

I imagine that in knives where the tolerance is tight, the "stiffness" to a greater degree is due to the "sheering" of the grease/lubricant.
 
I think that the reason that the tolerances are tight is for longevity. The reason that damascus blade Sebbies will be less smooth is that the metal has ridges. Also if you want to improve smoothness, I would suggest that you take the Sebbie apart and polish away the bead blasting in the pivot area. I've sent a couple of my Sebbies to Tom Mayo and I believe that is how he makes them smoother. Tightness of the pivot doesn't effect the blade on the Sebenza. It was made to be tight. The Sebenza is the only folding knife that I know of that is made this way. IME smoothness issues were the result of small debris in the pivot area and after a good cleaning (and proper re-assembly) they were just fine. I think that is why Chris meant for them to be taken apart and he's the only one I know of that encourages the knife to be taken apart. Try that with another knife and chances are you will void the warranty. The smoothest Sebenza I have is the first one I bought. Some of the others like the limited edition inlays and damascus bladed ones aren't as smooth only because I don't use them. Some less expensive knives may be "smoother", but as Archie pointed out, they may be made of less durable materials. But on the other hand Tom Mayo uses Teflon washers on his custom TNT's and I have never heard a complaint about blade play or smoothness or the durability of his knives. And last but not least the fact that I am left handed severly limits the availability of knives that I can use. The smoothness of the CRK folders has been a non-issue with me. And as Jardis points out, that is just my take on the situation at hand.:cool: :eek: :eek: ;) :p
 
I believe the stiffness is caused by the lock bar pressing against the blade. The lock on a sebenza puts a lot more pressure than some liner locks which is why the action may not move as freely.

If the Sebenza is supposed to have very high tolerances, shouldn't the assembly be made in such a way that the parts fit exactly together, with no play, yet don't need to have (barely) any force to hold it together?
Click to expand...

The parts do fit together perfectly. Try pushing over the lockbar so that it does not put any pressure on the blade and the blade should fall.
 
It's funny this topic should come up as I was just thinking about how I liked the smoothness of the Sebenza I had 10 years ago (wish I still had it) compared to the ones I've purchased over the past few years.

I think the older Sebenza's with the steel ball bearing in the lock bar were a lot smoother that the current model withe the ceramic ball bearing. In fact I think the older Sebenza's were the smoothest knives I've ever handled.

I think one reason Chris changed the ball bearing was to slow down the action. I can remember how smooth my first Sebenza was and how I would flip it open about a thousand times a day. One day I noticed that the lock was sticking and called Chris to talk about it. Chris said "you've been flipping it open haven't you?" to which I replied yes and was told to send the knife in and not flip it anymore when it comes back. Apparently the flipping damages the harded finish that engages the back of the blade and will eventually cause the lock to start sticking.

With all of that in mind it makes me think Chris changed the ball bearing just to prevent flipping.
 
Yes, I had considered that it might be the thick integral lock bar pushing against the blade that caused the stiffness and the (sometimes) stop-and-go action when opening slowly.

James Knight, sounds like I'd have liked the older Sebenza you had. But it makes me wonder, would the change from a ceramic ball detent from a steel one really make that much of a difference?
 
Jadis,

Sorry I wasn't clear on what I was talking about. To be specific what I meant was:

Smoothness: If one applies relatively constant pressure with the thumb then the knife will continue opening without jerkiness (apart from that annoying initial stop/go startup).

Firmness: The amount of effort needed to keep the knife opening (slowly) once it is going. I call knives that require very little effort 'freely opening' (don't ask me why I chose that term). e.g. a couple of my Benchmades are less firm (hence easier to open) than my large Sebenza. Same goes for my MT.

One thing I definately had to get used to (and I am still working at it) is how to start up my large Seb. I am experimenting with thumb and hand positions (while trying to keep my thumb thickness constant :D) trying to find that sweet spot.

I guess I better try a few of the other knives mentioned in this thread to get a better perspective. If your Sebenzas are not smooth then they are not. I won't contradict you ;).

James Knight, very interesting information. Thanks.

Cheers.
 
...wears significantly slower than stainless, heat-treated ball bearings such as those in just about every liner lock I've got. In fact, in one of my most used pieces, an AFCK with M2 blade steel, the ball detente has worn a bit of a flat surface on it where it contacts the blade.

As aforementioned, the Seb's pivot is either tightened all the way down, or it's not right. Ted, I think you were on the money in your first post. I'm not a Sebenzaholic by any means, however from an engineering perspective, everything on the Sebenza has been thought-out and then some (that's why of all the knives I've owned, custom and production, the small Seb has been in my pocket for 2 years and counting). Chris once said to me that he's put 10+ years of thought into the Sebenza, and in my opinion, it shows.

I too have had smoother operators, but long-term, my money's on the Seb for retention of tolerances. Great thread, by the way... :)

Professor.
 
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