F ball bearings! OK, maybe not so much now, opinion changing

Max Archer said:
For what it's worth, the vast majority of automotive engines still use solid bearings (the equivalent of knife washers) for most of their internal components. However, this is largely because it's impossible to get a ball/roller bearing onto a solid forged crankshaft, and it works because the bearings are all under active pressurized lubrication, which means the part to part interface is actually "riding" on pressurized oil and there's no direct metal on metal contact. That's why rod or crank bearings are the first thing to fail when there's a loss of lubrication.

My opinion is that bearing pivots are inherently superior for knives. However, they require proper engineering, and many knife companies seem to get it wrong, as evidenced by the Spyderco pics earlier in the thread. The major upside to bearings is that metal on metal contact, as with washers, will eventually wear the softer metal away, while bearings will run indefinitely without perceptible wear if properly engineered and manufactured. The problem is that most knifemakers are not engineers and they're treading new ground with bearings, and there's a lot less margin of error than with washers.
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These are bearings in a race, not sure I understand ?
[video=youtube;A6A825UvpnQ]https://www.youtube.com/watch?v=A6A825UvpnQ[/video]
[video=youtube;dNKIhIZLDyw]https://www.youtube.com/watch?v=dNKIhIZLDyw[/video]
 
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skyhorse said:
These are bearings in a race, not sure I understand ?
[video=youtube;A6A825UvpnQ]https://www.youtube.com/watch?v=A6A825UvpnQ[/video]
[video=youtube;dNKIhIZLDyw]https://www.youtube.com/watch?v=dNKIhIZLDyw[/video]
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That's on a turbine engine where the shaft is straight and you can slide the bearings onto it. With an automotive crankshaft you have multiple 90 degree "bends" and there's no way to slip a bearing onto it, you have to "sandwich" two halves of the bearing around the shaft.

It's technically possible to make roller bearing crankshafts and rod bearings, but they're quite rare and result in substantially more difficult manufacturing, higher costs, and potentially less reliable components. Single cylinder bike engines, for example, sometimes use roller rod bearings, but they do it by having a multi-piece crankshaft and that introduces a bunch of failure points that don't exist in a single-piece forging. It's also technically possible to have a multi-piece bearing, but that requires extremely precise tolerances that aren't practical in a production vehicle and so they only appear in stuff like Formula 1 cars or on handbuilt drag racing engines and the like.

It's also worth noting that even if that turbine doesn't have a straight shaft and therefore needs a multi-piece shaft or bearings, it's practical there because turbines are extremely expensive and have very strict maintenance and overhaul requirements.
 
I really don't understand why something as simple as pivot to open a folding knife needs the be over-engineered with bearings and other rubbish. It's a pivot for crying out loud, it opens the knife, look at the sebenza, Spydie Military, ZT0550, and countless other knives that have been around for ages - they open like they're on glass. Hell, my Becnhmade Adamas is STILL the smoothest opening and closing knife i have ever laid hands on, with absolutely zero play anywhere. Manufacturers need to pay more attention to either making better detents and polished large washers, OR - create a steel on steel interface for bearings to roll against so they aren't eating away at soft titanium as you open and close the knife. Bearings are just one more silly thing to possibly go wrong in a knife, especially in a frame lock where you already play the lottery with lock stick, tang to lock bar geometry, lock slip and lock rock as well as lock wear.
 
Mick_1KRR said:
I really don't understand why something as simple as pivot to open a folding knife needs the be over-engineered with bearings and other rubbish. It's a pivot for crying out loud, it opens the knife, look at the sebenza, Spydie Military, ZT0550, and countless other knives that have been around for ages - they open like they're on glass. Hell, my Becnhmade Adamas is STILL the smoothest opening and closing knife i have ever laid hands on, with absolutely zero play anywhere. Manufacturers need to pay more attention to either making better detents and polished large washers, OR - create a steel on steel interface for bearings to roll against so they aren't eating away at soft titanium as you open and close the knife. Bearings are just one more silly thing to possibly go wrong in a knife, especially in a frame lock where you already play the lottery with lock stick, tang to lock bar geometry, lock slip and lock rock as well as lock wear.
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Sounds like you are just listing things you don't like about certain knives.

Luckily for you, there are plenty of knives out there that have features you do like. :)

I don't think manufacturers need to change anything about the way they are doing things.

If all manufacturers were only making frame-lock knives with bearings, well, then a complaint that they needed to change their ways would have a need.
As they are pumping out more types of knives than any of us can hope to afford (even those who, unlike me, have a high-paying job), there does not seem to be any reason to be annoyed at the way things are.
 
stabman said:
Sounds like you are just listing things you don't like about certain knives.

Luckily for you, there are plenty of knives out there that have features you do like. :)

I don't think manufacturers need to change anything about the way they are doing things.

If all manufacturers were only making frame-lock knives with bearings, well, then a complaint that they needed to change their ways would have a need.
As they are pumping out more types of knives than any of us can hope to afford (even those who, unlike me, have a high-paying job), there does not seem to be any reason to be annoyed at the way things are.
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Nah, you've missed the point, the point was about over-engineering a simple pivot function. Plus, it's not that i don't like them, it's that they are structurally implemented with a disregard to long term stability. Why do you think titanium fame lock knives were later upgraded with steel inserts. Also why CRK hardens his Ti interface, also why Hinderer does the same. If a maker made a pure soft Ti on Steel interface for a lock bar these days people would clearly see it as a design flaw. The pivot area is of no exception if you ask me, it is under abrasive contact just as much as a lock bar and also lateral stress in certain uses. But hey, if it's cool and makes it flip out super fast i guess all is ok right? I can't understand this logic.

But i do agree that there are plenty of knives for all of us, so all one has to do luckily is avoid the things they don't like and move along. I do enjoy discussing it tho.
 
Mick_1KRR said:
I really don't understand why something as simple as pivot to open a folding knife needs the be over-engineered with bearings and other rubbish. It's a pivot for crying out loud, it opens the knife, look at the sebenza, Spydie Military, ZT0550, and countless other knives that have been around for ages - they open like they're on glass. Hell, my Becnhmade Adamas is STILL the smoothest opening and closing knife i have ever laid hands on, with absolutely zero play anywhere. Manufacturers need to pay more attention to either making better detents and polished large washers, OR - create a steel on steel interface for bearings to roll against so they aren't eating away at soft titanium as you open and close the knife. Bearings are just one more silly thing to possibly go wrong in a knife, especially in a frame lock where you already play the lottery with lock stick, tang to lock bar geometry, lock slip and lock rock as well as lock wear.
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Chris reeve uses bearings in the ti-lock. And he has even taken his awesome washers and skeletonized them to reduce friction and carry lubricant like bearings do. Polished washers actually make a knife slower as two polished surfaces sandwiched together creates a vacuum and resistance.


Mick_1KRR said:
Nah, you've missed the point, the point was about over-engineering a simple pivot function. Plus, it's not that i don't like them, it's that they are structurally implemented with a disregard to long term stability. Why do you think titanium fame lock knives were later upgraded with steel inserts. Also why CRK hardens his Ti interface, also why Hinderer does the same. If a maker made a pure soft Ti on Steel interface for a lock bar these days people would clearly see it as a design flaw. The pivot area is of no exception if you ask me, it is under abrasive contact just as much as a lock bar and also lateral stress in certain uses. But hey, if it's cool and makes it flip out super fast i guess all is ok right? I can't understand this logic.

But i do agree that there are plenty of knives for all of us, so all one has to do luckily is avoid the things they don't like and move along. I do enjoy discussing it tho.
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Sometimes features are added to a knife not because of any real need but because people hypothosize publicly that something will be a problem despite any real evidence of such. Will bearings wear on ti? Sure will. Will it continue to be a problem to the point of a failure? No it wont. When you see a knife with hardened steel inserts and you see one without its simply a matter of two different paths to reach the same destination. Just like a steel lockbar insert isnt needed but some people see temporary lock stick and a deformed lockface as an uneccessary evil and need to "correct a problem" that really wasnt a problem at all. At the end of the day bearings are just another option and the fact you dont like them doesnt mean anything but you not liking them. The position that bearings are unnecessary can be applied to a multitude of other knife features found in other types of knives. You just happen to dislike this particular feature. And there are plenty of options without it.
 
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Well I hate Ferraris, overpriced, temperamental sports cars for guys having a midlife crisis. I should say that I have never owned one, driven one or even been in one.
 
PURPLEDC said:
Chris reeve uses bearings in the ti-lock. And he has even taken his awesome washers and skeletonized them to reduce friction and carry lubricant like bearings do. Polished washers actually make a knife slower as two polished surfaces sandwiched together creates a vacuum and resistance.




Sometimes features are added to a knife not because of any real need but because people hypothosize publicly that something will be a problem despite any real evidence of such. Will bearings wear on ti? Sure will. Will it continue to be a problem to the point of a failure? No it wont. When you see a knife with hardened steel inserts and you see one without its simply a matter of two different paths to reach the same destination. Just like a steel lockbar insert isnt needed but some people see temporary lock stick and a deformed lockface as an uneccessary evil and need to "correct a problem" that really wasnt a problem at all. At the end of the day bearings are just another option and the fact you dont like them doesnt mean anything but you not liking them. The position that bearings are unnecessary can be applied to a multitude of other knife features found in other types of knives. You just happen to dislike this particular feature. And there are plenty of options without it.
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Just because Chris Reeve put them on one smaller EDC knife does not mean they are an upgrade of any sorts to the function of a pivot. That's why you won't find them on the 2017 CRK's, or even upcoming ones i'd wager, or any other of his knives meant for hard work. And you seriously cannot compare a skeletonized large diameter washer to ball bearings...Apples and oranges, the surface area of that skeletonized washer is probably 100 times more than the tiny peaks of each of those ball bearings. Not even in the same league when it comes to lateral stability.

Are you seriously saying that a non hardened titanium lock bar on metal blade tang wasn't a problem? you do realize ZT started implementing the steel insert on the 560's because of excessive warranty repairs on that model right? The lockbar would travel from 15% to 90% on some models because of variances and inconsistency in the angles put on the lock bar and blade tang. The one i owned and used personally did just that, it wore significantly in a matter of months of barely any hard use or excessive flipping until it had lock rock, and it was loud lock rock like an old strider.

Liking or disliking the bearings on soft plain Ti is beside the point, it's a structural downgrade and an un-needed one. I'm talking strictly structural integrity here, not who likes this and that for the fun aspects of knife flipping. Surface area is surface area, you can't really argue with facts. It's like saying you are more stable leaning against a wall using your fingertips than the flat of your hand.
 
Ugh, I hate the weather channel. Why does it show up on my DirecTV guide? That channel is the worst, Bravo is so much better. I don't understand why they even make a channel like the weather channel--who even cares about the weather? There should only be reality shows, because they're my favorite.

If you don't like knives with bearings, buy any of the thousands of knives without bearings.

On a related tangent, what does it say about us as Internet forum users that troll threads like this one almost always go on for many pages?
 
Mick_1KRR said:
Just because Chris Reeve put them on one smaller EDC knife does not mean they are an upgrade of any sorts to the function of a pivot. That's why you won't find them on the 2017 CRK's, or even upcoming ones i'd wager, or any other of his knives meant for hard work. And you seriously cannot compare a skeletonized large diameter washer to ball bearings...Apples and oranges, the surface area of that skeletonized washer is probably 100 times more than the tiny peaks of each of those ball bearings. Not even in the same league when it comes to lateral stability.

Are you seriously saying that a non hardened titanium lock bar on metal blade tang wasn't a problem? you do realize ZT started implementing the steel insert on the 560's because of excessive warranty repairs on that model right? The lockbar would travel from 15% to 90% on some models because of variances and inconsistency in the angles put on the lock bar and blade tang. The one i owned and used personally did just that, it wore significantly in a matter of months of barely any hard use or excessive flipping until it had lock rock, and it was loud lock rock like an old strider.

Liking or disliking the bearings on soft plain Ti is beside the point, it's a structural downgrade and an un-needed one. I'm talking strictly structural integrity here, not who likes this and that for the fun aspects of knife flipping. Surface area is surface area, you can't really argue with facts. It's like saying you are more stable leaning against a wall using your fingertips than the flat of your hand.
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Yes I am saying a standard titanium lockbar presents no issues if the user of the knife isn't a brain dead idiot doing crap to their knife to intentionally see if it will fail. Often times causing the failure themselves. Idiot proofing a knife isn't the same thing as making a better knife. People buying a knife and the first thing they do is open it as hard as they can a million times, then turning the knife around and smacking the spine up against a table a hundred times until they deform the lockbar so much that it eventually fails. ZT had an issue with lockstick and used the insert as a fix. What do zt people whine about after that? Now the lock moves over too far if I use my kung fu grip and don't remember that pivots need to be tightened.

Its funny you will use chris reeve as an example of how things should be done but only when it serves your position. He doesn't use steel lockbar inserts. In fact titanium framelocks had been made a couple decades before lockbar inserts became a thing. The real problem as I see it are people having unrealistic expectations of what a folding knife is and isn't. As for your complaint that bearings are by no means a comparison to chris reeves skeletonized washers? The folder in my pocket with 47 bearings on each side of the pivot in three rows begs to differ. You act as if their is only one type of bearing system. There isn't by the way their are many.

Either way you are bringing up a point that is almost comical to me as lateral stress is something you should be trying to avoid with a folding knife regardless of the pivot type. I cant think of any company that promotes their folding knife as a pry bar. The point I'm trying to make is that even if we can agree that a folder with washers is stronger than a bearing folder its a moot point as a bearing equipped knife in most cases is stronger than it should ever need to be in the first place if used as the tool it was designed to be. A knife. You can always build something thicker and stronger. But who gives a crap if one knife can handle 200lbs of lateral stress and another 300 when you shouldn't be subjecting a blade to lateral stress in the first place? A steel block for an engine is usually much stronger than an aluminum block. But if you are only pumping 200 horse power through it, it makes no difference. I'm not saying you have to like bearings. Dislike them all you want. But people keep on talking about how much weaker they are and unnecessary. Every single issue people bring up is usually not an issue at all. Its just preference. And its another option for those who like them. But these completely farcical tales of inferiority really are unwarranted especially seeing in 20 years ikbs has been around and the 10 years production knives have had bearings I have not seen a single instance of an actual failure. Ive seen issues due to neglect, and I have seen wear that ceases after a race is formed and I have seen a lot of posturing that they are inferior. But no actual accounts of those failures. It reminds me of the early 90's when dudes would tell me my sunglasses couldn't take a .22LR to the lens like their oakleys and I have to remind them that I am trying to stop sunrays not bullets. Any knife you have. Any one, I don't care what it is could be made thicker, heavier and out of more sturdy materials. But what does that matter if you don't need that extra strength? You don't like them? fine. But please this conjecture that they are weaker would only be relevant if bearing knives were constantly failing to perform their task of being a knife. That doesn't happen.
 
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I never paid attention before to bearings and washers, now I do, thanks guys for getting me deeper into the rabbit hole :)
Now I understand why my Chaves is so lightning fast despite its bulky blade.

Personally I like both and won't favor any system.
 
Isn't any pivot a point of potential weakness? If so, by parity of reasoning, why have folding knives at all?
 
Interesting perspective. I've never had any issue with any of my BB EDC users. They open and close smoothly after years of use and feel less gritty than my washer knives. To each his own, but my BB knives are keepers.
 
I strongly suggest that the next time someone tries to force you to buy a knife that doesn't have the features you like - say "no, thank you."
 
I find that the lube in bearing pivots lasts much longer than washer pivots. Washers are easier to maintain, but for me the difference is marginal. I won't refuse a knife based on the type of pivot it has. If I had to estimate, half my knives have bearings and half use washers... I love them all.
 
I have never owned a ball bearing knife, but I have to say that I share a lot of the concerns people have voiced about bearing pivots. It's just simple physics that the same amount of force will be focused a lot more if it's being distributed by only a few tiny ball bearings than if it's spread out over the entire surface of a washer. It's also common sense that a ball bearing has a lot more potential to get grit and assorted crap in it than a washer pivot, and I work with enough bearings in machinery to know that that can be a very bad thing. Basic experience and knowledge show me that there is added potential for problems with ball bearing pivots in dirty, hard use like my knives often see.

So what am I going to do about it? I'm going to order a ZT0909 because the overall design looks like it will meet my needs very well. I'm going to cut open bags of salt, bentonite and ready mix concrete with it. It will be subjected to swirling dust and chaff that gets EVERYWHERE. Occasionally it will unavoidably get filled with soupy, gritty mud, sometimes while it's still in my pocket, unfortunately. I will use it like any of my other knives (sometimes pretty hard) and clean and maintain it as needed like any of my other knives. I will not do spine whacks or use it as a pry bar. I have a large variety of pry bars so I don't need my folders to do that. After I use it for many months, then I'll know if those potential problems are problems in practice, or only in theory. Only after that am I going to make a real judgement on how practical bearing pivots might be for what I do. I suspect I'll find that they're just fine, but I'll have to actually use one to know. Just saying.
 
hexenjager said:
I have never owned a ball bearing knife, but I have to say that I share a lot of the concerns people have voiced about bearing pivots. It's just simple physics that the same amount of force will be focused a lot more if it's being distributed by only a few tiny ball bearings than if it's spread out over the entire surface of a washer. It's also common sense that a ball bearing has a lot more potential to get grit and assorted crap in it than a washer pivot, and I work with enough bearings in machinery to know that that can be a very bad thing. Basic experience and knowledge show me that there is added potential for problems with ball bearing pivots in dirty, hard use like my knives often see.

So what am I going to do about it? I'm going to order a ZT0909 because the overall design looks like it will meet my needs very well. I'm going to cut open bags of salt, bentonite and ready mix concrete with it. It will be subjected to swirling dust and chaff that gets EVERYWHERE. Occasionally it will unavoidably get filled with soupy, gritty mud, sometimes while it's still in my pocket, unfortunately. I will use it like any of my other knives (sometimes pretty hard) and clean and maintain it as needed like any of my other knives. I will not do spine whacks or use it as a pry bar. I have a large variety of pry bars so I don't need my folders to do that. After I use it for many months, then I'll know if those potential problems are problems in practice, or only in theory. Only after that am I going to make a real judgement on how practical bearing pivots might be for what I do. I suspect I'll find that they're just fine, but I'll have to actually use one to know. Just saying.
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Well i can definitely appreciate you having concerns, and you have my respect seeing you are going to figure out for yourself if they are right for you. Just a bit of advice. If you do have an issue and need to flush your bearing system and dont wish to take it apart do so with lighter fluid or naptha. There is no water content to leave behind so steel balls will not rust. Especially if you follow up with oil or grease in a syringe.
 
PURPLEDC said:
Well i can definitely appreciate you having concerns, and you have my respect seeing you are going to figure out for yourself if they are right for you. Just a bit of advice. If you do have an issue and need to flush your bearing system and dont wish to take it apart do so with lighter fluid or naptha. There is no water content to leave behind so steel balls will not rust. Especially if you follow up with oil or grease in a syringe.
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Thanks for the advice! :thumbup:
 
That's the way to do it hex!
My money says you'll love it and will be keeping, and enjoying, it!
Let us know what you think!
Joe
 
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