Have you seen a ball bearing pivot fail?

[RX-79G]

Are you really not getting this? Seriously? For the last time and read it slowly. Since my experience is my experience it doesnt mean it didnt happen because you had a different result occur in your experience. I stand by my claim that I have never had a bearing headset fail in my years of riding bmx nor my peers. YOU did. So because you did my experience cant be true? And all of a sudden you take my one single instance of personal experience and turn it into a blanket statement claiming I said that bearing headsets dont pit? I said that MINE DIDNT and I didnt even use a specific term I simply said mine didnt fail. If you dont know the difference between a single personal experience given as an example and a generalization I dont know why I am even bothering debating with you. When you take something I say and twist it and put words in my mouth then what is the "engineering" term non engineers use impress others to describe it? I only ask because that is the term I want to use so you dont get confused and twist my words further.

I missed your other long rant. My apologies.

Look, I think you are doing some of the things you are accusing me of. So let's both stop whatever that is.

Specific to your posts:

A race is whatever the balls ride on. It doesn't matter how it is made, out of what, or anything else. "Race" is the word for the surface they run on.

"Work hardening" is a general term for what happens to some metals when they are deformed. On some metals it has a negative connotation, like aluminum. On other metals it adds strength. If there is a claim that IKBS makes the race surface harder, I'd like to see that. I don't know if that is going to happen or not with 6/4 titanium, and I have reason to believe it will not. But I'd be happy to read anything you might have specific to 6/4 and roll/deformation hardening. I could not find anything about it myself, which doesn't surprise me because titanium is not a material that is much used for high wear or compression, like IKBS is using it for.

There is no debate that you can form a race surface through plastic deformation in 6/4, and that a steel bearing will dent titanium. What seems to be the disconnect is that "dent" and "pit" describe two very different effects. A pit is a surface fracture that usually occurs from abrasion on hard surfaces - like walking over dried mud. "Denting" is like walking over wet mud. Very different.


Unfortunately, a preponderance of positives doesn't disprove a negative. Not observing a failure is like not seeing air. Permanently damaged 6/4 races in knives may not be a problem at all, and if Archie's scoring is the only example ever, than it isn't a problem. And I haven't said it is a widespread problem - I've just said that it all seems pretty sketchy considering that no other industry would make a bearing race for steel balls out of anything with a Rc in the low 30s.

The main thing that bothered me was this statement:

My example of bicycle headset bearings was only used because of my personal experience. But you having a differing experience doesnt automatically discredit my example. It simply means you had different results.

It really doesn't mean that. It means that your sample size was too small, and the experience of all bicycle users would disprove your sample. Pitted headsets aren't a weird thing I saw, it is a normal wear item known throughout the sport and industry, which I unsuccessfully tried to educate you about. If you would prefer to believe what you didn't see was just as valid, I don't know what to say to that attitude.

 

[ursamajor]

I see some people saying they don't like ball bearing pivots because it has more moving parts and whatnot, and they're worried it might fail.

So have any of you seen a ball bearing pivot break?

Do you mean the pivot breaking, or just the lock failing (closing without the user intending it to do as such)

 

[Fire_Brand]

RX-79G I definitely think you are making good points, and have fair arguments.

I think it is a logical conclusion that with enough cycles or pressure the titanium, being significantly softer than the bearings, will wear out. The thing that is hard to prove is that is there really enough movement (just opening and closing a knife) or enough pressure?

If someone is trying to come to a conclusion as to what direction they should go probably the best bet is choose a knife that has hardened steel races. They will likely never wear out, but if you happen to mess them up somehow you can just pop them out and replace them. Then you enjoy all the benefits of bearings without any of the potential issues.

As far as the gunk or debris argument... keep your knife clean people. They aren't indestructible and we can all come up with scenarios that will ruin whatever device you come up with. In general use it seems that the answer really is no, bearings aren't this finicky thing that will gunk up as soon as you stick it in your pocket so don't worry about it. If it gets dirty blow it out, simple as that. I honestly don't see what the big deal is regarding this argument...

 

[PURPLEDC]

I missed your other long rant. My apologies.

Look, I think you are doing some of the things you are accusing me of. So let's both stop whatever that is.

Specific to your posts:

A race is whatever the balls ride on. It doesn't matter how it is made, out of what, or anything else. "Race" is the word for the surface they run on.

"Work hardening" is a general term for what happens to some metals when they are deformed. On some metals it has a negative connotation, like aluminum. On other metals it ads strength. If there is a claim that IKBS makes the race surface harder, I'd like to see that. I don't know if that is going to happen or not with 6/4 titanium, and I have reason to believe it will not. But I'd be happy to read anything you might have specific to 6/4 and roll/deformation hardening. I could not find anything about it myself, which doesn't surprise me because titanium is not a material that is much used for high wear or compression, like IKBS is using it for.

There is no debate that you can form a race surface through plastic deformation in 6/4, and that a steel bearing will dent titanium. What seems to be the disconnect is that "dent" and "pit" describe two very different effects. A pit is a surface fracture that usually occurs from abrasion on hard surfaces - like walking over dried mud. "Denting" is like walking over wet mud. Very different.


Unfortunately, a preponderance of positives doesn't disprove a negative. Not observing a failure is like not seeing air. Permanently damaged 6/4 races in knives may not be a problem at all, and if Archie's scoring is the only example ever, than it isn't a problem. And I haven't said it is a widespread problem - I've just said that it all seems pretty sketchy considering that no other industry would make a bearing race for steel balls out of anything with a Rc in the low 30s.

The main thing that bothered me was this statement:


It really doesn't mean that. It means that your sample size was too small, and the experience of all bicycle users would disprove your sample. Pitted headsets aren't a weird thing I saw, it is a normal wear item known throughout the sport and industry, which I unsuccessfully tried to educate you about. If you would prefer to believe what you didn't see was just as valid, I don't know what to say to that attitude.

You are officially hopeless. AGAIN!!!!!! I am not arguing anything about the bearings besides saying my results were not the same as yours. I am NOT saying that your experience isnt the norm. I am not saying what you experienced was a fluke. And I can accept it is normal wear. All I said was just because that is your experience it does not mean my experience didnt occur. My bearings did not fail. Why are you reading into it more than that? You are creating a non existent argument.

If I come on the forum and say I have never had a brain freeze from drinking a slurpy all I am saying is I didnt have a brain freeze. If you have had them then fine. If you and your friends and all your relatives get brain freezes from a slurpy that doesnt mean I had to have had one and just didnt know what a brain freeze is. It just means my experience was different than yours. Sample sizes only matter if you are trying to verify something outside your own experience. I am not trying to do that. I have admitted this so many times yet you keep hammering the BS point home that I dont understand how bearings in bikes work. Now I do but that doesnt mean my bearings also failed. They didnt and that is all I said. My experience. And I am not saying that because my bearings didnt fail in the headset of my bike that yours couldnt have either. This is what I am talking about with you creating an argument that doesnt exist and twisting my words. So drop the bike thing will you? As to your other quote I didnt even read it. I simply dont care.


Did you read this or did you miss it as well? It talks various titanium alloys. You would know better than I if the information is in there you are seeking.
http://dspace.mit.edu/bitstream/handle/1721.1/42485/25097927.pdf?

 

[The Aflac Duck]

My brain hurts from all these bicycle and slurpee analogies

What are we even discussing anymore

 

[crom]

Bearings in a knife pivot will only fail in the sense they would get dry dirty and ultimately gritty. The blade will still open and lock so all else can be remedied. My concern would be availability of replacement pieces years down the road. I will buy a knife when it comes with Bones Swiss caged bearings haha!

 

[stabman]

Most answers are going to be no. Most people haven't seen a plane crash either, but that doesn't mean they never do. The relative importance of "no" answers is pretty low.

So were the "yes" answers here...bear with me a moment.
The question was "will the pivot fail."

The supposed "yes" answers you reference were not actually yeses, because the pivot did not fail.
It got a little stiff or "gritty", but no failure occurred in any sense of the word.

My Buck/Tops CSAR-T (which has washers) got slightly "gritty" action-wise after the last woods outing I used it for.
That is not a failure...it is slightly less smoothness.

So, if the question had been "Do bearing equipped knives sometimes become less smooth in opening?", then the answer would be yes.
But the answer to the actual question, as stated by the original poster, has so far been no all across the board.

No failures reported yet...sorry.

 

[RX-79G]

So were the "yes" answers here...bear with me a moment.
The question was "will the pivot fail."

The supposed "yes" answers you reference were not actually yeses, because the pivot did not fail.
It got a little stiff or "gritty", but no failure occurred in any sense of the word.

My Buck/Tops CSAR-T (which has washers) got slightly "gritty" action-wise after the last woods outing I used it for.
That is not a failure...it is slightly less smoothness.

So, if the question had been "Do bearing equipped knives sometimes become less smooth in opening?", then the answer would be yes.
But the answer to the actual question, as stated by the original poster, has so far been no all across the board.

No failures reported yet...sorry.

If you want to take that point of view, there is no such thing as "bearing pivot" knife. All these knives have solid pivots, with bearings on the side of the blade to keep it running parallel to the scales. How those bearings located so far from the pivot post could hurt that post is beyond me.

Which is why I think you might be mischaracterizing the thread OP.

 

[stabman]

If you want to take that point of view, there is no such thing as "bearing pivot" knife. All these knives have solid pivots, with bearings on the side of the blade to keep it running parallel to the scales. How those bearings located so far from the pivot post could hurt that post is beyond me.

Which is why I think you might be mischaracterizing the thread OP.

Nope, you're just grasping at straws now is all.
Failure of a pivot would entail not being able to open it...unless someone was talking about it breaking in half, which we all know isn't the case.

But hey, if you want to continue on the Great Anti-Bearing Crusade, have at it. :thumbup:
But it seems you're running low on anti-bearing munitions at the moment.

 

[ron_m80]

Analyzing any mechanism must be done with material science and physics in mind.

As an example;
I think the sliding jaw pliers Gerber makes on their multi-tool are incerdibly strong despite using cheap and simple materials. There are more parts than if it were simple a solid steel jaw that slid in and out of the handles, but that would actually be inferior to more cheap parts in the case of the Gerber.

 

[PURPLEDC]

Nope, you're just grasping at straws now is all.
Failure of a pivot would entail not being able to open it...unless someone was talking about it breaking in half, which we all know isn't the case.

But hey, if you want to continue on the Great Anti-Bearing Crusade, have at it. :thumbup:
But it seems you're running low on anti-bearing munitions at the moment.

what I THINK he was trying to say is that bearing pivot knives dont actually exist because the pivot doesnt actually have bearings. The bearings fit over the pivot but the pivot itself is independent of the bearings and simply support the blade in relation to the pivot.. But again this is why you cant win with him because he takes everything so literal that if you say the sky is blue he would say no and explain why the sky actually only looks blue but is made of a variety of colors. Its word manipulation when he very well knows what you mean. But because that isnt EXACTLY what was said he exploits it.

 

[stabman]

what I THINK he was trying to say is that bearing pivot knives dont actually exist because the pivot doesnt actually have bearings.

Yep, I know what he was saying...and everyone here already knew that, and just didn't decide to nitpick on the wording of the OP because we all knew what he was talking about.

Well hell, let's redefine away...according to certain philosophical concepts, nothing except my own consciousness exists.
Hence, no one that disagrees with me can be correct, because they do not exist.
Any disagreements I think I perceive are only manifestations of my fractured psyche working at greater integration.

 

[Tyronethepro]

Using my Foresight working construction and not maintaining it like I know I should by cleaning it and such, I've never had a problem with the pivot. It's been dropped in dirt, used to cut gypsum board, used around tons of paint dust while my hands were crusted with it and the dust was even in my pocket. No problems with the IKBS, and after all of the use, I'm not expecting there to be.

 

[RX-79G]

Yep, I know what he was saying...and everyone here already knew that, and just didn't decide to nitpick on the wording of the OP because we all knew what he was talking about.

Well hell, let's redefine away...according to certain philosophical concepts, nothing except my own consciousness exists.
Hence, no one that disagrees with me can be correct, because they do not exist.
Any disagreements I think I perceive are only manifestations of my fractured psyche working at greater integration.

And what I was getting at is that you have defined "failure" so narrowly, no possible "failure" could ever exist. The bearings could be rust away and the blade would still open. Just as a destroyed wheel bearing won't prevent the wheel from turning.

Is that your intent?

 

[kniferbro]

FWIW, here are some pics of the race on the Ti side of my 0562, which has been my "KVT T&E" knife. Subjected to lateral loads and the like, flipped a million times. I run my pivots really tight.

You can see the races aren't symmetrical or uniform and dents from the ball bearings. Still smooth.

 

[bpeezer]

IMHO, this doesn't prove anything, it just shows one variable. Have you tried cutting hundreds of feet of rosin paper that's been covered in gypsum dust? I have, and I can tell you first hand that dust will affect a bearing system. Try cleaning a pivot that's been covered in gypsum without taking it apart... It won't happen. Lubrication will just turn the gypsum into a paste and further affect the action.

Dipping the knife in fibers and flipping it a couple times doesn't simulate a dusty work environment, it doesn't even allow time for the particulate to settle into the track; which is what will affect the action.

It does prove something...it proves that briefly burying an IKBS knife in pine-based kitty litter won't cause failure

Personally, I'm more likely to drop a knife in kitty litter than I am to cut hundreds of feet of gypsum covered rosin paper. I certainly don't claim to have performed a FMEA on bearing pivots! Honestly I was expecting the dusty litter to bind the pivot right away, so I was pleasantly surprised with the result.

 

[flarp]

Have never seen one fail or break on my ZTs, Kershaws, or CRKTs.

 

[RevDevil]

Some of you arguing are unable to see the forest through the trees, again. You know who you are. The same thing happens when certain people try and "contribute" something to a thread. What they don't know is that what they contribute is empty argument. Way to tank a thread. :thumbdn:

 

[NeilB]

Wouldn't it make more sense to define exactly what we mean by failure before we ask the "Did it fail?" question?

 

[RX-79G]

Wouldn't it make more sense to define exactly what we mean by failure before we ask the "Did it fail?" question?

I believe Stabman did.