Ball Bearing Pivot Durability

M

MatthewSB

Gold Member
Joined
Feb 1, 2013
Messages
1,631
There are more and more knives available with ball bearing pivot systems. I haven't bought one yet because phosphor bronze washers have worked well for me for so long I didn't want to mess with something that was any sort of complicated, for fear of issues down the road from not leaving well enough alone.

I'm considering buying a ZT 0560, or another ZT with the KVT bearings, but wanted to hear from people who've gotten a chance to use theirs. I'm sure ZT wouldn't put out junk, but would appreciate the reassurance.

Thanks in advance.
 
The only pitfall of a a ZT bearing knife is that they do not use any type of buffer from the bearings to the titanium. The only thing that happens is that if you continue to torque down the pivot the bearings will over time cold roll a race into the handle. This wear eventually stops entirely because the metal gets work hardened and the bearings just stop going deeper as they are cradled more by the hardened Ti. Some companies use hardened steel washers as a contact point but it isnt necessary. Bearing systems these days are no more complicated than a PB washer equipped knife. They are simply using washers with bearings built into them. Only certain true IKBS type bearings systems are a PITA to work on because the bearings are loose and can fall out and about when disassembling the knife. Especially if you use a thinner lubricant instead of grease which holds the bearings in place.

One thing to remember though is that you may not need bearings to be happy. I prefer them but this idea that bearing knives are guaranteed to be smoother is a bit of a myth. The real advantage of a bearing system is that if your pieces are all machined properly they are a self centering system. And they take a lot of guess work out of setting up a good action on a knife. They do reduce drag at the pivot but it is rarely felt by the person using it. This reduction in drag allows you to be able to crank a little harder on the pivot without creating a binding effect. Im sure when you have dialed in a washer knife many times 1/8 of a turn on the screw is too much and the blade chokes up and wont budge. This is greatly reduced on a bearing knife. But you can get just as smooth and fast action out of a washer knife. It just takes more elbow grease. The real area that needs attention on making a knife smooth is the detent combined with the locbar tension. These two things are what really causes the majority of drag on a blade when opening or closing. And this is the resistance most people will feel in there hand as a blade swings open. A zt 560 is a decent knife and yes overtime the bearings will wear into the Ti scale if you keep cranking the pivot but again its nothing to worry about.
 
Last edited:
I've had absolutely no problems with the KVT bearings in my 0561. Super smooth, but the way the pivot tension is set it doesn't fall free without a gentle shake. With occasional (twice in a year) cleaning and maintenance I've had no problems with them wearing out or getting clogged up with dust/dirt. Pick up a 560 without worry, it's a fantastic knife. Now that I have it back from KAI for maintenance (old untreated lock bar wore out) with the new steel lockbar insert it's quickly become my very favorite knife, surpassing even my CRKs. Flips fantastically well, super comfortable in hand, locks up like a vault, easy to sharpen, and holds a working edge for months.
 
PURPLEDC said:
The only pitfall of a a ZT bearing knife is that they do not use any type of buffer from the bearings to the titanium. The only thing that happens is that if you continue to torque down the pivot the bearings will over time cold roll a race into the handle. This wear eventually stops entirely because the metal gets work hardened and the bearings just stop going deeper as they are cradled more by the hardened Ti. Some companies use hardened steel washers as a contact point but it isnt necessary. Bearing systems these days are no more complicated than a PB washer equipped knife. They are simply using washers with bearings built into them. Only certain true IKBS type bearings systems are a PITA to work on because the bearings are loose and can fall out and about when disassembling the knife. Especially if you use a thinner lubricant instead of grease which holds the bearings in place.

One thing to remember though is that you may not need bearings to be happy. I prefer them but this idea that bearing knives are guaranteed to be smoother is a bit of a myth. The real advantage of a bearing system is that if your pieces are all machined properly they are a self centering system. And they take a lot of guess work out of setting up a good action on a knife. They do reduce drag at the pivot but it is rarely felt by the person using it. This reduction in drag allows you to be able to crank a little harder on the pivot without creating a binding effect. Im sure when you have dialed in a washer knife many times 1/8 of a turn on the screw is too much and the blade chokes up and wont budge. This is greatly reduced on a bearing knife. But you can get just as smooth and fast action out of a washer knife. It just takes more elbow grease. The real area that needs attention on making a knife smooth is the detent combined with the locbar tension. These two things are what really causes the majority of drag on a blade when opening or closing. And this is the resistance most people will feel in there hand as a blade swings open. A zt 560 is a decent knife and yes overtime the bearings will wear into the Ti scale if you keep cranking the pivot but again its nothing to worry about.
Click to expand...

Well said:thumbup:

IMO bearings are a lot of hype. A lot of it comes down to the overall design of the knife, tight tolerances are key. Think CRK.
 
Blues Bender said:
Well said:thumbup:

IMO bearings are a lot of hype. A lot of it comes down to the overall design of the knife, tight tolerances are key. Think CRK.
Click to expand...

They are a very good example of how bearings are not needed. I am an oddball. I simply like them. And I feel they are easier to dial in. But needed? Not even close. CRK makes a fine knife. And they even created perforated washers the further reduce friction by reducing surface contact area. Still, I a would LOVE if Mr. Reeve would make a flipper sebbie with thrust bearings. Pure want is all it is.
 
Bearings are not needed IMO. Many flippers flip just fine with out them. I like to think less moving parts the better but that's just me.
 
I have 2 spyderco knives with a ball bearing lock up, the blue manic and the manic xl..they preform exelente with hard use, no problems here.
 
I own a ZT0560, Microtech Socom Delta, and a Chris Reeve Sebenza (among other knives) and I will say this. My Sebenza is a very smooth knife, it will fall closed when the lock bar is disengaged however, my ZT has a "smoother" action. By that I mean the ZT will fall closed easier, and is faster to deploy, but the Sebenza has less snags while opening and closing. Then there's my Microtech with its ceramic bearings riding on steel inserts, this is the SMOOTHEST knife I own. Once the detent is overcome, the blade has almost zero friction. If I hold the knife closed in my hand and the tip down, make a Very subtle movement swinging my wrist, the blade opens immediately.

Long story short, yes, bearings make knives much smoother. I don't know if I would like IKBS because it isn't a captured bearing system, but KVT and Microtech's bearings are amazing. As for durability, you would have to open your knife 10's of thousands of times to wear the Titanium on a 0560 to the point that you noticed it. Trust me, my 0560 is my favourite knife to flip when I'm bored.
 
I have a 561 that is perfect. Opens with the stud as nicely as with the flipper. Great knife.

I haven't tested it heavily in the wild yet so not sure how it would hold up under bush tasks. I don't think you'll have any worries urban EDC.

Ultimately though, as in SHTF circumstances, I'd think a bearing pack would require maintenance of some kind before a good P/B washer equipped knife would.
 
Bearings certainly have their advantages but with lateral force such as prying the ball bearings can dent the inner titanium scales. Caged bearings likely cause dents more easily than even ikbs since there are fewer ball bearings. Not sure how big of an issue this is but I've seen at least one case of it. Just something to keep in mind. On a hard use knife I would prefer PB washers.
 
My 0560 got squeaky and had certain parts of the opening with more friction than the rest. No idea why. Hope it doesn't happen with my 0561.
 
I won't avoid a knife with bearings, but I'd much rather have washers with good tolerances. My guess is it's easier for companies to get super smooth opening with poor tolerances using bearings than it is washers. It's much too easy to get grit and junk into ball bearings used in most folders but I use my knives in the desert in the field a lot. I also prefer a more fluid tension when opening a knife, and ball bearings in my opinion tend to "get away" from you unless it's a flipper. I like that with washers you can dial in some tension if you want. I've also noticed that I have a couple bearing knives that tend to squeak when opening/closing.

Overall I just see them as a lot of little moving parts that don't really have any advantage, and the uncaptured bearing versions, what a nightmare to service/clean/lube.
 
Between the Spyderco Southard, and the Buck Marksman, I'm loving the ball bearing pivots. If there ever was an issue, they will fix them, so I'm not worried. They have extensive testing, if something were flawed they would know by now.
 
Thanks for all of the great responses, everyone.

I'm not nearly as concerned about issues from ball bearing pivots. However, ZT and CRK make such smooth opening knives using PB washers, I think it'll be a while before I mess with anything else. I don't think I'll be trying the ball bearing pivot anytime soon.
 
My Benchmade AXIS knife blade falls freely into the handle when I pull back on the lock bar. I am a tinkerer and DIY guy, do most of my own mechanical maintenance and repair of household appliances, automobiles etc. I am of the philosophy that less is more when dealing with moving parts. I see bearing pivots as a luxury feature, certainly not required for any reason at all. If I were to buy one I'd opt for the bearings in some sort of cage and not the loose ones you see on the CRKT knives. Sealed bearings ala skateboard bearings would be the best IMO, maybe those already exist.
 
bpeezer said:
Ever seen a Sebenza blade freefall back into the handle?
Click to expand...

I have. And that would be because of the detent and changing the lube from grease to a thinner material.

JoHnYKwSt said:
Bearings certainly have their advantages but with lateral force such as prying the ball bearings can dent the inner titanium scales. Caged bearings likely cause dents more easily than even ikbs since there are fewer ball bearings. Not sure how big of an issue this is but I've seen at least one case of it. Just something to keep in mind. On a hard use knife I would prefer PB washers.
Click to expand...

Honestly I dont feel any folder bearing or washer equipped is the best tool to be prying with. IMHO if you are using a knife for what a knife is designed for there is really no negative side to a bearing pivot.
 
EChoil said:
I have a 561 that is perfect. Opens with the stud as nicely as with the flipper. Great knife.

I haven't tested it heavily in the wild yet so not sure how it would hold up under bush tasks. I don't think you'll have any worries urban EDC.

Ultimately though, as in SHTF circumstances, I'd think a bearing pack would require maintenance of some kind before a good P/B washer equipped knife would.
Click to expand...

I don't think you have to worry...

http://www.bladeforums.com/forums/showthread.php/949197-ZT0561-Mudbucket!!!!!
 
You must log in or register to reply here.
Back
Top