Have you seen a ball bearing pivot fail?

[The Aflac Duck]

This is just one test, but you should check out IKBS's website they really throw some impressive tests at it and have a bunch of great videos showing the reliability of the system.

I have seen plenty of tests that show the reliability of loose bearings and really no evidence that shows them jamming up. It seems like even in a worst case scenario the knife wouldn't freeze up it just would be a little slow which is the everyday reality of a knife with washers (obviously with some exceptions).

The "everyday reality" of washers is not sluggish action, not sure why you believe that to be true. Washers are just as good as bearings granted that they are integrated into a well-designed knife. I have a lot of types of bearings systems, and a lot of washer knives. I'm not making this up...

I never said that a bearing system had failed on me, just stated my observations under heavy amounts of dust.

 

[RX-79G]

I have never had any issues with my bearing pivots, and in response to them wearing out faster I don't really see this as a concern for a number of reasons. First you can simply tighten the pivot and you are good to go and if in your life-time it starts to wear into the handles the channel cut will cup the bearings more providing more surface area reducing the speed that the bearings would wear the material.

In real life, this doesn't work. If you start to get pitting, you can't make it go away by tightening everything down and re-flattening the raceway. All that will happen is the pits will get worse.

Short of re-machining the races, you can't fix pitted races. And there would have to be enough space in the system to remove more material.

 

[PURPLEDC]

Why quote me at all?

Why not quote other people who also qualified their "No" with a statement about things getting in the pivot?

The added frustration of bearing pivots because of sensitivity to dust, dirt and other particles, as well as the inconvenience of disassembly and reassembly for pivots with loose bearings, are why I won't be purchasing another one. That doesn't mean I think bearing pivots are more likely to fail.

Its probably because people notice you are one of the most active people in the argument against bearing knives yet every reason you cite as being a problem you havent personally experienced. You simply arent speaking from an informed opinion based on experience but rather taking possibilities you have never realized and promoting them as problematic issues. What you have isnt even a theory as theories are based on supporting evidence and proof. You have a hypothesis rooted in what ifs. Of the two people who have reported bearing issues one of them openly admits it is an above normal amount of debris of a specific type and that it didnt result in a failure but a compromise of optimal effectiveness. The other i dont find too credible for various reasons. One of those reasons being that sticky fruit juice will harm the action of any knife. Not just one that rides on bearings.

 

[Fire_Brand]

The "everyday reality" of washers is not sluggish action, not sure why you believe that to be true. Washers are just as good as bearings granted that they are integrated into a well-designed knife. I have a lot of types of bearings systems, and a lot of washer knives. I'm not making this up...

I never said that a bearing system had failed on me, just stated my observations under heavy amounts of dust.

Sorry, I wasn't trying to imply that you said or suggested that it failed. I'm more saying that most evidence shows reliability rather than any kind of issues (considering only the videos I've found, I tried to look for some showing failures as well). I also wanted to point out the fact that there are many videos apart from the one posted showing IKBS bearings exposed to worse conditions.

I also have had some incredibly smooth knives on washers myself where the blade can fall closed, but it's hard to debate the fact that bearings are pretty much universally smoother and faster than washers, especially when you get into ceramic bearings. There absolutely are exceptions to this but most of the time that is going to be comparing the best washers to the worst bearings.

 

[skyhorse]

Not only have I never had a ball bearing pivot fail,I've never had a problem with a Ti frame lock W/O the steel inserts as well.

 

[RX-79G]

Sorry, I wasn't trying to imply that you said or suggested that it failed. I'm more saying that most evidence shows reliability rather than any kind of issues (considering only the videos I've found, I tried to look for some showing failures as well). I also wanted to point out the fact that there are many videos apart from the one posted showing IKBS bearings exposed to worse conditions.

I also have had some incredibly smooth knives on washers myself where the blade can fall closed, but it's hard to debate the fact that bearings are pretty much universally smoother and faster than washers, especially when you get into ceramic bearings. There absolutely are exceptions to this but most of the time that is going to be comparing the best washers to the worst bearings.

It is just debatable whether smoother, faster opening are attributes so important to a knife that the increased cost, maintenance and risk of permanent damage is worthwhile.

Bearings are not 100% upside.

 

[The Aflac Duck]

I hear you. I by no means find washers superior either, I've actually had problems with my Sebenza getting dusty due to the perforated washers. When opening/closing, some of the perforations are exposed, allowing dust/debris to easily channel inside; it's very easy to clean though.

A dusty bearing knife will work perfectly fine under heavy amounts of dust, but I'd be lying if I told you it has no effect whatsoever. Sluggish action doesn't equate to failure, however, I try to avoid this sluggish action, especially on flippers.

Also, bearings don't make a difference in smoothness (ie, the blade falling under its own weight), that's due to the detent type/shape and lockbar pressure. My sebenza falls closed under its own weight if I push the lockbar aside. I like bearings, but I don't see any advantage to them.

Sorry, I wasn't trying to imply that you said or suggested that it failed. I'm more saying that most evidence shows reliability rather than any kind of issues (considering only the videos I've found, I tried to look for some showing failures as well). I also wanted to point out the fact that there are many videos apart from the one posted showing IKBS bearings exposed to worse conditions.

I also have had some incredibly smooth knives on washers myself where the blade can fall closed, but it's hard to debate the fact that bearings are pretty much universally smoother and faster than washers, especially when you get into ceramic bearings. There absolutely are exceptions to this but most of the time that is going to be comparing the best washers to the worst bearings.

 

[PURPLEDC]

In real life, this doesn't work. If you start to get pitting, you can't make it go away by tightening everything down and re-flattening the raceway. All that will happen is the pits will get worse.

Short of re-machining the races, you can't fix pitted races. And there would have to be enough space in the system to remove more material.

I often see you saying things cant be done. But yet many of these things i have seen happen. I know you are an engineer right? Still i am reminded of the quote "man who says it cannot be done should not interupt the man doing it". What is being described concerns a bearing knife with caged bearings that didnt have a cold forged race or milled race but rather a knife that simply had a pocket milled to accept a captured set of bearings which simply ride on two completely flat surface. Sometimes due to lateral torque when the blade is not moving the bearings will make tiny indents into the handle material. Most times i cant even feel these indents as the bearings spin. But i have had those divots smooth out as that surface wears.

It is just debatable whether smoother, faster opening are attributes so important to a knife that the increased cost, maintenance and risk of permanent damage is worthwhile.

Bearings are not 100% upside.

Anything is debateable. but in his situation nothing is rooted in a need. As such its simply personal preference as to what features are important to the individual. You have to remember what you find unimportant another guy will find essential and there really is no way to prove an opinion wrong that is based solely in a want. what bearing flippers have you owned that your hypothesis have actually evolved into a problem?

 

[RX-79G]

I often see you saying things cant be done. But yet many of these things i have seen happen. I know you are an engineer right? Still i am reminded of the quote "man who says it cannot be done should not interupt the man doing it". What is being described concerns a bearing knife with caged bearings that didnt have a cold forged race or milled race but rather a knife that simply had a pocket milled to accept a captured set of bearings which simply ride on two completely flat surface. Sometimes due to lateral torque when the blade is not moving the bearings will make tiny indents into the handle material. Most times i cant even feel these indents as the bearings spin. But i have had those divots smooth out as that surface wears.




Anything is debateable. but in his situation nothing is rooted in a need. As such its simply personal preference as to what features are important to the individual. You have to remember what you find unimportant another guy will find essential and there really is no way to prove an opinion wrong that is based solely in a want. what bearing flippers have you owned that your hypothesis have actually evolved into a problem?

And I often read your examples, like bicycle headset bearings, that disprove your arguments. I have a fair amount of real world experience with both bearing systems and metal work. The indentations you're describing probably don't qualify as pits, because the metal is so soft. That doesn't mean that soft metal can't pit.


The purpose of these threads is to discuss the pluses and minuses of bearings. The stuff I bring up is not theory.

 

[PURPLEDC]

And I often read your examples, like bicycle headset bearings, that disprove your arguments. I have a fair amount of real world experience with both bearing systems and metal work. The indentations you're describing probably don't qualify as pits, because the metal is so soft. That doesn't mean that soft metal can't pit.


The purpose of these threads is to discuss the pluses and minuses of bearings. The stuff I bring up is not theory.

ok, then what technical term would be used for an indentation made in metal because a ball bearing was pressed into it and it leaves a dent that can be seen as well as felt? And if afterwards wear erases any trace of their previous existence what is that called? The problem i have with you telling people they are wrong is because you never offer an explanation that supports your claims. Its always something along the lines of, because i know what i am talking about. How do i know that what you say is true. And when you present these problems you see with bearing knives and they never seem to materialize in any ones personal use why do we just take your word on faith? many of us arent engineers and i dont know all the terms they use. And it frustrates the hell out of me because engineers are a lot like classically trained musicians. They think within a set of rules and they wont explain those rules to the lower life forms and simply say you are wrong yet wont elaborate. There has to be a way to dumb it down so the average person understands your argument.

And my examples dont disprove my arguments. We simply have different results with the same medium. You seem to feel that since YOU have seen problems with bearings in bicycles then my story cant be valid based on your case of differing results? Either way many times you point to other applications for bearings and use those results to denounce their effectiveness in aknife though you dont seem to account for different loads, environments and other variables that will change the end result.

 

[craytab]

No, but cleaning, disassembly and reassembly are much more frustrating. Plus, while bearing pivots are smoother than washer pivots when clean, once little bits of grit and lint get into the bearings (which can happen within a week) they're often worse than a washer pivot.

Not true at all. And in fact, the next time you made this claim you qualified it with loose bearings. That is a solid argument but to say all bearing knives are hard to take apart and clean is wrong, unless you have a hard time taking apart ANY knife to clean.

BTW, I have not had to take apart either of my 0560s in several years of regular EDC. So this whole "they'll fill up with dirt in a week and not work" argument must be an issue you have personally had with your bearing pivot knives. Can you elaborate on how you get so much dirt in your bearing pivot knife within one week on a regular basis?

I really don't have a preference of bearings or washers. I love the smoothness of my 0560s but my 0550 is just as smooth. The 915 triage whitty sent me today is more smooth than all of them :thumbup:

 

[PURPLEDC]

Not true at all. And in fact, the next time you made this claim you qualified it with loose bearings. That is a solid argument but to say all bearing knives are hard to take apart and clean is wrong, unless you have a hard time taking apart ANY knife to clean.

BTW, I have not had to take apart either of my 0560s in several years of regular EDC. So this whole "they'll fill up with dirt in a week and not work" argument must be an issue you have personally had with your bearing pivot knives. Can you elaborate on how you get so much dirt in your bearing pivot knife within one week on a regular basis?

I really don't have a preference of bearings or washers. I love the smoothness of my 0560s but my 0550 is just as smooth. The 915 triage whitty sent me today is more smooth than all of them :thumbup:

Actually he has admitted that none of the reasons he has cited for bearing knives being inferior he actually has never had happen. Which is what frustrates me so much about this argument. People with no first hand experience with any problems pushing them as realities.

"Man bearing knives are much more irritating to work on and debris is much more likely to fowl up the action"

Oh wow man you must have had a bad experience to feel that way. What happened?

"Oh nothing. .......(crickets) but just trust me"

 

[Fire_Brand]

And I often read your examples, like bicycle headset bearings, that disprove your arguments. I have a fair amount of real world experience with both bearing systems and metal work. The indentations you're describing probably don't qualify as pits, because the metal is so soft. That doesn't mean that soft metal can't pit.


The purpose of these threads is to discuss the pluses and minuses of bearings. The stuff I bring up is not theory.

A bit of a hyperbole but try putting washers on a bicycle and see how well it rides! More seriously bearings wearing out on a bicycle is a terrible example considering you could put on several lifetimes worth of cyclical wear in terms of what a knife goes through in a single afternoon on a bike. If my bearing knives last for as many rotations as a bicycle bearing I don't really see the problem...

 

[RX-79G]

ok, then what technical term would be used for an indentation made in metal because a ball bearing was pressed into it and it leaves a dent that can be seen as well as felt? And if afterwards wear erases any trace of their previous existence what is that called? The problem i have with you telling people they are wrong is because you never offer an explanation that supports your claims. Its always something along the lines of, because i know what i am talking about. How do i know that what you say is true. And when you present these problems you see with bearing knives and they never seem to materialize in any ones personal use why do we just take your word on faith? many of us arent engineers and i dont know all the terms they use. And it frustrates the hell out of me because engineers are a lot like classically trained musicians. They think within a set of rules and they wont explain those rules to the lower life forms and simply say you are wrong yet wont elaborate. There has to be a way to dumb it down so the average person understands your argument.

And my examples dont disprove my arguments. We simply have different results with the same medium. You seem to feel that since YOU have seen problems with bearings in bicycles then my story cant be valid based on your case of differing results? Either way many times you point to other applications for bearings and use those results to denounce their effectiveness in aknife though you dont seem to account for different loads, environments and other variables that will change the end result.

I am not an engineer. I use simple terminology that is easily available to anyone with a search engine. And I borrow from my real life experience making and servicing knives and machinery. My experience and knowledge comes from more places than just knives and knife related website material. I'm not sure why that is a sin.

In another thread you argued that soft metal races work harden. You didn't have a reference for that, but if it is true then you can't expect the metal to remain soft enough to iron out forever.

"Pitting" is when the pressure on the race causes the surface to fracture, not dent. Once the metal is gone, it is gone. Rolling it will only cause the edges of the pit to fracture more.


All this would be just academic nonsense if we were talking about $40 Gerbers. But for someone choosing between $500+ knives, maybe a little discussion about long term durability and serviceability isn't so inappropriate?


As I've said before, for most people none of this matters. But most people could have all their real world cutlery needs met with a Camillus Cub Scout knife. If we are going to talk about high end steels, lock failure and bearings - be prepared to discuss what happens when you actually put some wear on them.


You know what would be an ideal solution to all of this? PB or brass ball bearings. They would be the sacrificial part in the system, rather than a race in a pricey titanium scale.

 

[craytab]

Actually he has admitted that none of the reasons he has cited for bearing knives being inferior he actually has never had happen. Which is what frustrates me so much about this argument. People with no first hand experience with any problems pushing them as realities.

"Man bearing knives are much more irritating to work on and debris is much more likely to fowl up the action"

Oh wow man you must have had a bad experience to feel that way. What happened?

"Oh nothing. .......(crickets) but just trust me"

Yup. That is why I asked him to again provide evidence, which he can't. We might be back to agreeing! (but surely will argue about something later )

A bit of a hyperbole but try putting washers on a bicycle and see how well it rides! More seriously bearings wearing out on a bicycle is a terrible example considering you could put on several lifetimes worth of cyclical wear in terms of what a knife goes through in a single afternoon on a bike. If my bearing knives last for as many rotations as a bicycle bearing I don't really see the problem...

Very true about bike bearings.

 

[craytab]

So where are all these dirty pivots and ruined races? (yeah, I said dirty pivot)

Let's see them!

 

[PURPLEDC]

I am not an engineer. I use simple terminology that is easily available to anyone with a search engine. And I borrow from my real life experience making and servicing knives and machinery. My experience and knowledge comes from more places than just knives and knife related website material. I'm not sure why that is a sin.

In another thread you argued that soft metal races work harden. You didn't have a reference for that, but if it is true then you can't expect the metal to remain soft enough to iron out forever.

"Pitting" is when the pressure on the race causes the surface to fracture, not dent. Once the metal is gone, it is gone. Rolling it will only cause the edges of the pit to fracture more.


All this would be just academic nonsense if we were talking about $40 Gerbers. But for someone choosing between $500+ knives, maybe a little discussion about long term durability and serviceability isn't so inappropriate?


As I've said before, for most people none of this matters. But most people could have all their real world cutlery needs met with a Camillus Cub Scout knife. If we are going to talk about high end steels, lock failure and bearings - be prepared to discuss what happens when you actually put some wear on them.


You know what would be an ideal solution to all of this? PB or brass ball bearings. They would be the sacrificial part in the system, rather than a race in a pricey titanium scale.

The reason its a sin as you call it is because other applications of bearings many times will have a completely different set of variables and circumstances that would make a bad application of bearings in one item perfectly acceptable in another. 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.

I did in fact have a source for bearing races work hardening. Apparently you never clicked the link to the ikbs website. Actually i just found your post that says its not on the site. I promise you it WAS there at some point either that or flavio explained it on a forum at some point. Either way you are citing your use of technical terms and their ease of discovery with a google search so why not practice what you preach and look it up?

I also dont know why you are using the term pitting and defining it when you feel it doesnt apply. I never used the term to begin with. I said dents and divots.

No one has placed a value on the subject matter. This whole thread is based on bearings regardless of price. And with bearing knives being around as long as they have without any real issues i would say that yes it is rather pointless to try and point to potential inferiorities when no real cause for concern has ever arisen. Its like people starting to panick when they find out raw potatoes are toxic even though we have been consuming them for many moons with little incident.

And if you are going to present non issues as a problem without any cause to belive so then be prepared to be asked why you feel that way without any basis.

http://en.m.wikipedia.org/wiki/Work_hardening

http://dspace.mit.edu/bitstream/handle/1721.1/42485/25097927.pdf?...

 

[RX-79G]

A bit of a hyperbole but try putting washers on a bicycle and see how well it rides! More seriously bearings wearing out on a bicycle is a terrible example considering you could put on several lifetimes worth of cyclical wear in terms of what a knife goes through in a single afternoon on a bike. If my bearing knives last for as many rotations as a bicycle bearing I don't really see the problem...

There are several headsets that use thrust bearings on the top cups rather than bearings. It seems like a perfectly useful analogy if you want to talk about machines used in the real world, rather than on youtube.

Mechanical watches also use thrust bearings made of sapphire, not ball bearings.

 

[RX-79G]

The reason its a sin as you call it is because other applications of bearings many times will have a completely different set of variables and circumstances that would make a bad application of bearings in one item perfectly acceptable in another. 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.

I did in fact have a source for bearing races work hardening. Apparently you never clicked the link to the ikbs website. Actually i just found your post that says its not on the site. I promise you it WAS there at some point either that or flavio explained it on a forum at some point. Either way you are citing your use of technical terms and their ease of discovery with a google search so why not practice what you preach and look it up?

I also dont know why you are using the term pitting and defining it when you feel it doesnt apply. I never used the term to begin with. I said dents and divots.

No one has placed a value on the subject matter. This whole thread is based on bearings regardless of price. And with bearing knives being around as long as they have without any real issues i would say that yes it is rather pointless to try and point to potential inferiorities when no real cause for concern has ever arisen. Its like people starting to panick when they find out raw potatoes are toxic even though we have been consuming them for many moons with little incident.

And if you are going to present non issues as a problem without any cause to belive so then be prepared to be asked why you feel that way without any basis.

http://en.m.wikipedia.org/wiki/Work_hardening

http://dspace.mit.edu/bitstream/handle/1721.1/42485/25097927.pdf?...

I used the term "pitting", because that is the correct term when talking about manufactured bearing races. In this thread, Archie used the term "scoring" for permanent race damage, which is what I referenced.

You have proposed that soft races can dent without it being permanent, but are also insisting that the races become work hardened from use. Please pick one.


Now, what is it that you promise used to be on a website, but is now gone, that I am in charge of proving existed at one time?


I have 10 years of experience servicing bicycle headsets. Are you really proposing that your experience with one headset not being damaged makes you just as much of a subject matter expert on headsets races?



I think you have a very strange idea about how information is supposed to be valued and conveyed. I you want to demonstrate an idea, you post the reference to it. If you want to go on experience, why not acknowledge those with real experience?

 

[Daniel Dorn]

Based on my Personal Experience, I've noted that a bearing system can easily be over-tightened, to the point of causing drag. Granted it's not excessive, but it is noticeable. With both knives (Stedemon Bastion, Reate District-9), it was easy enough to back off the pivot screw in tiny increments to where everything was butter smooth, and there was no play, even when force was used.

Just something to consider. Compared to washer systems, it's still a win in my book.