strider/ buck strider

[DaveH]

There's also a difference between the philosophy of how to build a lock and the actual building of the lock. There have not been recent threads concerning Strider locks, so maybe things are better now.

 

[Cliff Stamp]

... wouldn't you agree that the Messer Magazine test demonstrates that his design/fit produces a pretty strong lock?

Slow load strength has never been a concern, Walker demonstrated this when he first built the locks. The problems come in regards to high speed impacts and torques.

-Cliff

 

[STR]

I've been thinking of a multiple choice quiz on integral locks ever since this thread prompted me to start looking deeper into these folders. For what purpose I don't know. Maybe just to show the example of questions to consider on these style of locks or to give some idea of the difference in opinions on the building of them. Many of these choices are quotes or para phrases of actual replies to me when the question was asked of a maker.

The quiz goes something like this in my head.

1) How sharp of an angle should the lock contact area be on the blade?

A) Sharp

B) Not so sharp but nearly flat

C) Flat

D) Concave and sharp

E) Convave and more straight or flat

F) It doesn't matter so long as the lock is secure


2) Thinking of the width of the lock. How much lock should contact the blade on an integral lock folder?

A) Just enough to know it contacts the blade as far from the pivot as possible

B) As much as possible away from the centerline of the pivot without allowing blade rock

C) All of it

D) Doesn't matter so long as the blade doesn't rock


3)Thinking of the thickness of the lock itself. How far out, or how much of the thickness of the lock on an integral or liner or frame locking style folder should move out to get behind the blade to securely lock it open?

A) Just enough to come into blade contact

B) 25%

C) 50%

D) 75% or more


4) How wide should the lock be for optimal security?

A) Half the width of the body of the folder

B) One third the width of the body of the folder

C) Only as wide as the contact area

D) Doesn't really matter so long as it is wide enough to look balanced on the folder.


5) How long should the long cut of the lock be?

A) Should be long so it is easy to move sideways when you want to close it.

B) Should be short to be of maximum resistance to accidental closure

C) Should be 3/4s of the length of the body of the folder.

D) Doesn't matter so long as it works


6) How deep should the relief areas be on a frame lock folder where the lock bends?

A) Half the thickness of the lock

B) Only deep enough to make bending the lock easy when you first set the spring.

C) Just take it down until it looks good.

D) Deep enough to allow the lock to move easy with the thumb.


7) Depending on your answer to question 2: Where should the lock contact the blade. In other words, what part of the lock should be in contact with the blade?

A) The top only

B) The bottom only

C) The middle only

D) Just the top and the middle

E) Just the bottom and the middle

F) All of it


8) The Stop pin should idealy be placed

A) Even with the lock

B) Ahead of the lock

C) Behind the lock

D) Doesn't much matter at all


9) Should the stop pin be screwed down or just held in place by pivot pin tension?

A) It should be screwed down so it doesn't rattle or fall out if the pivot tension gets loose

B) It should be allowed to spin freely so it doesn't wear in one spot only

C) It should be flat like the blade and all one piece with the spacer bar

D) Doesn't matter at all whichever is easiest for the maker (s).


10) The stop pin and blade contact should be

A) Round with a recess cut out in the blade of the same half moon shape so they mesh together over greater surface area to decrease wear.

B) Round bumping against the flat of the blade only

C) Flat so it hits the flat spot on the contact area of the blade

D) Simply doesn't matter.


11) How much access for the thumb ramp is best for releasing the lock?

A) Only the absolute minimum to prevent accidental closure

B) Lots so it doesn't hurt or require looking to close the lock

C) None. The lock should be made with non sharpened serrations and to stick up higher than the scales to enable easy access.

D) It doesn't matter at all.

12) What material should the integral lock be made of?

A) Work hardened brass

B) Titanium

C) Hardened stainless steel

D) Hardened tough carbon steel

E) Any of the above so long as it is thick enough to be strong and secure in normal use.



I could go on; as this is just the tip of the iceberg but this gets the point across. The funny thing about this is that depending on who you ask you will get different answers to each question and different arguments as to which is correct, proper or best.

None of the other lock types being made have this kind of controversy surrounding them. Whats even more frightening about it is that some guys making these style of knives may not have even considered any or only some of these questions.

Other things that come to mind are questions of lock stability. For example some claim that only the bare minimum of the lock needs to come out to contact the blade because it will make the lock last longer since it will wear and move farther in with use. If you have ever had one that barely engages the blade and call for a service or send it in this is often brought up as the reasoning for it by many makers. This has happened to me. What puzzles me is, if this is true then the maker is pretty much admitting that wear will be a factor for the lock by building them this way yet they will argue until they are beat red in the face that a 2.5mm lock contact surface area at the interface is adequate and acceptable and that the lock can take the shocks associated with that small of a contact area in their tactical knife. Its quite a paradox to me on this issue and thats just one of many.

STR

 

[Cliff Stamp]

How many of the people arguing for one design or another have actually used any of the designs to the point of failure and are basing the decisions on actual facts. How much of it is also based on not what can be done ideally but what is actually possible to do in a shop. What is the machining difficulty of getting a perfectly mating face the entire length vs just at one end?

-Cliff

 

[STR]

These are all very good questions Cliff. I am not qualified to answer them though.

Ernie said to me in his last reply the following. I don't think he will mind me making this public. This is nothing less than he has stated publically before so here is his quote.

STR

"Yes, you can perfectly mate up the liner lock face
to the blade interface. There is no question about that.
However, there is one factor that this does not account
for - wear. For example if the back of the blade wears
where it slams into the stop pin or if the stop pin
develops wear (a flat spot) you will then have a knife,
that when opened, rotates a little farther around until it
stops. This will then completely negate full lock
interface and the lock would start to contact further
towards the top of the spring face. Prove it to yourself
by setting up a perfect 100% lock engagement and then
grind 3 or 4 thousandths off of the back of the blade
where it contacts the stop pin. You will have rock. It
is not "Old School", it is basic mechanical engineering
and projected wear factors. Most knife makers are not
engineers, and I'm not saying they should be, but when you
are designing mechanical devices, it does come in handy.

I am a mechanical engineer and I was a tool designer as
well as a prototype machinist and a tool and die maker. I
came up through an apprenticeship program and had to
honestly know not only what I was doing, but why. I know
it sounds like I'm bragging but I have all of the NC
machinery of a state of the art manufacturing facility at
hand. I do things for a reason, not because it is the way
I was taught. It is the same dogma I fight every day in
the training modules that I design for the government.
"But we always did it this way." Believe me, my entire
being is driven by the search for the better and more
efficient ways of doing things, better teaching
presentations, more efficient dissemination of
information, more retainable techniques, better auxiliary
training methodologies and yes, better manufacturing
technologies, more efficient business practices and in the
end better knives. If I see a better way of doing
something, I analyze it, I try it and if it is indeed
better, I embrace it. I give seminars and motivational
talks to business owners and corporate entities about
innovation as a tool for success, of course, along with
many other factors, so as I hope you see . . .

I never rest on the norm, or "as it was taught to me" as a
foundation for anything I do. It either works or it
doesn't."

 

[MrMojoRising]

I have two of the Buck Strider 889 models. The first had some issues with the blade coating but the newer model seems to have that resolved. I carry both and find them to be well made and sturdy. I rotate my EDC from an Emerson, Spyderco, Benchmade and Microtech. I would have no problem working the 889 into the rotation at some point.

 

[Hair]

I used a Buck/Strider, it was one of the worst liner locks I have seen, Mick Strider noted that the behavior was to be expected in regard to torque failure. I asked him specifically if the Striders were any better and could they meet or surpass the work done on the Spyderco Chinook. He declined to answer.

Now forget about Strider, forget about knives. You go out and buy VCR X, it has problems if you leave it on too long, you return it, the guy tells you yeah it is a problem with model X. A few weeks later you hear that there is a new version of model X, more expensive but this one is made in US, the other ones were Taiwan and basically rips.

You go into the store and ask if the new model X has the same problem. The guy refuses to answer and either changes the subject or ignores you and deals with other customers. You then see another store with another brand, Y, and you ask them the same question. They say no, that isn't a problem with ours and we guarantee it. Which one would most reasonable people buy.

You then ask the people who use the newer model X, do they have a problem , they all say no. You then further ask them did they have problems with the one made in Taiwan which had a known issue the company admitted, they say no to that as well. What does this tell you about the fact they had no problems with the newer model? This is basic logic.

You are talking about what Mick does. I am asking about the knives. Not what you think they can do based on Mick's actions, but what they *ACTUALLY* can do.

The next logical step up with be batoning which has been openly advocated by some such as Doug Ritter on his RSK. Now do you really want to argue that the huge Striders are "abused" by work which is easily handled by the zytel and much slimmer RSK's? Strider promotes their knives for military and combat use, take your knife and use it as Mick Strider has promoted which includes such work as violent jackhammer stabs into moving hard targets. Now consider the impact of all your body weight torquing and impacting on the lock and compare this to a spine whack.

I never said a spinewack is the end-all and be-all of lock tests. I specifically said it wasn't. So what is your point?

It doesn't test strength at all, it is a check on security, Joe Talmadge has wrote on length on the subject, they are two very different matters.

Actually, it does test the strength, Cliff.

The ironic thing here is that the design proposal that Strider has explaining the lock is based on theory, they have no hard data at all to support their idea, yet you don't question this at all or demand anything from them, however when the idea of pressure is brought up you dismiss this as "just" theory.

You are confused. I am not taking Strider's theory to be a fact and then calling STR's theory "only a theory". They are both theories, and as far as I can see, they both work. I have a Sebenza, and I have an SMF and I have found the locks to be very solid. I do not need any data to show me this, the knives themselves show me this. What I need is data to prove otherwise, because I do have evidense that the Strider way of doing locks does work. I also have evidence that the CRK way works too. I am not blinding following a theory, I am going by reality.

If someone is going to say one way is better than the other, yes, I want more than a theory. Needing more than a theory from one side does not mean I am blinding following the other side. I never said that I believe the Stider way is better than the CRK way. I would need evidence of that as well.

Please do not put words into my mouth.

I have seen knives with small amounts of engagement both crush and fracture due to the pressure and shear forces which result. The reason that you don't see reviews by guys like Joe and Steve on liners and integrals is that they have moved past them due to frequent problems, they have noted this in detail in the past.

It is actually ironic that their lack of critism is somehow taken as a positive, if anything it is the reverse.

When did I say their lack of critism was a positive? I have known that they have a strong dislike of liner locks (and to a lesser degree, framelocks). Again, please do not put words into my mouth.

But what does this have to do with *ANYTHING* Cliff?

I am talking about a CRK-style framelock versus a Strider-style framelock. I don't care what Joe thinks about liner or frame locks. I am comparing two framelocks!

There is one theory that the CRK way is better, and one theory that the Strider way is better.

I don't give a crap about the theories.

I own a Sebenza and an SMF, and I find the locks to be very solid- moreso than any of my other liner or framelocks.

Both knives have a very good rep for lock strength.

I am asking if there is any evidence that one lock is noticably better than the other in terms of stength or wear.

So far, even with all of the words you type, you haven't even tried to provide me any evidence or point me in the right direction. All you do is try to nitpick my arguements that are not wrong or illogical in the first place.

 

[Cliff Stamp]

You are talking about what Mick does.

No I am talking about what I have seen with a knife he designed, and what he has said about the design in general.

[spine whack]

Actually, it does test the strength, Cliff.

No it doesn't. When knives fail spine whacks such as you performed, they don't do so for lack of strength, if strength was exceeded the liner or tang would be bent. Spine whacks induce failure due to problems with mating, thus locks with really thin liners which are really weak, can pass spine whacks while locks with really thick liners, which do really well in slow loads, fail them readily. Joe Talmadge clearfied this point years ago. What you did which is a check on security and has nothing to do with the overbuilt nature of the knife or lock, slim gentleman folders can pass it easily.

When did I say their lack of critism was a positive?

When you used the lack of it as part of your arguement.

Both knives have a very good rep for lock strength.

Lock strength is rarely an issue and never has been for liners/integrals. The issue has always been with security, as I noted in the above, Walker demonstrated the very high strength of liners when he first introduced the lock.

So far, even with all of the words you type, you haven't even tried to provide me any evidence or point me in the right direction.

I have shown your direct evidence on numerous times, you just ignore it. I have seen locks which mate right at the front compress readily, this is basic pressure, there is no way to argue against that fact, it is like arguing that if you made the blade thinner it would only be a "theory" that it would be weaker. Strider's arguement for the design is based on counter torque in regard to vertical play, it does not deal with torque along the other axis, or break points when overloaded vertically.

The easiest way to understand it would be to just extend the idea to its fullest so that the lock mates just on the extreme far end at a point and it should be obvious then it will shear/compress even under light force, it is simply a matter of pressure. Just model it with wood and watch what happens if you torque across two wide mating surfaces or just have one at a point, in fact just sketch it out and ask any carpenter what will happen, then ask him if it is "just theory" and see what they say if you refuse to believe it. It is unlikely that they will think in terms of torque or pressure, but it will be obvious to them what will happen.

-Cliff

 

[Hair]

No I am talking about what I have seen with a knife he designed, and what he has said about the design in general.

Yes, Cliff, and this proves the design is inferior how?

No it doesn't. When knives fail spine whacks such as you performed, they don't do so for lack of strength, if strength was exceeded the liner or tang would be bent. Spine whacks induce failure due to problems with mating, thus locks with really thin liners which are really weak, can pass spine whacks while locks with really thick liners, which do really well in slow loads, fail them readily. Joe Talmadge clearfied this point years ago. What you did which is a check on security and has nothing to do with the overbuilt nature of the knife or lock, slim gentleman folders can pass it easily.

Cliff, when you do a spine wack, it applies a load to the lock. This load can break the lock. If the lock survives, it did so because it could handle the load. This is usually called strength. Since you admit that bending the liner during a spine wack would be testing the lock's strength, then why have I bent the liner on one of my knives doing a spike wack test? If you apply a load to something to see if it will break it, it's a strength test, Cliff. That doesn't mean a spine wack cannot test other things, but don't say it isn't also a strength test. Again, don't nitpick when there isn't anything wrong.

When you used the lack of it as part of your arguement.

Actually Cliff, I didn't. Please pay attention.

Lock strength is rarely an issue and never has been for liners/integrals. The issue has always been with security, as I noted in the above, Walker demonstrated the very high strength of liners when he first introduced the lock.

Never been an issue? Then how did you bend the lock on the SERE 2000 during batoning? How have I bent the liner on some flea market knife during a spine wack?

I have shown your direct evidence on numerous times, you just ignore it.

Heresay isn't evidence, Cliff. Expecially when you aren't even trying to answer the question at hand. To make this clear for you, I am comparing two schools of lock design. Where is your evidence that one is better than the other? Please quote yourself.

I have seen locks which mate right at the front compress readily, this is basic pressure, there is no way to argue against that fact, it is like arguing that if you made the blade thinner it would only be a "theory" that it would be weaker. Strider's arguement for the design is based on counter torque in regard to vertical play, it does not deal with torque along the other axis, or break points when overloaded vertically.

You have also broken locks that make full contact. So how does this prove one is better than the other, Cliff?

The easiest way to understand it would be to just extend the idea to its fullest so that the lock mates just on the extreme far end at a point and it should be obvious then it will shear/compress even under light force, it is simply a matter of pressure. Just model it with wood and watch what happens if you torque across two wide mating surfaces or just have one at a point, in fact just sketch it out and ask any carpenter what will happen, then ask him if it is "just theory" and see what they say if you refuse to believe it. It is unlikely that they will think in terms of torque or pressure, but it will be obvious to them what will happen.

That's very funny.

Obviously putting the same amount of force onto a smaller area will result in a greater psi. I understand why you think the Strider lock should be inferior.

But Cliff, titanium is not wood, and the Strider lock contact isn't the size of a nail.

If this failure point was the only failure point, or even the weak link in the chain, then your proposed test would be very useful, but it isn't.

I think even Strider would admit that putting a given load onto a smaller point results in a greater psi at that point. But Strider suggests that this downside comes with an upside.

So I guess this is the Cliff runaround that everyone talks about.

 

[Buzzbait]

So I guess this is the Cliff runaround that everyone talks about.

Hehehe... What took you so long?

 

[ginshun]

The easiest way to understand it would be to just extend the idea to its fullest so that the lock mates just on the extreme far end at a point and it should be obvious then it will shear/compress even under light force, it is simply a matter of pressure. Just model it with wood and watch what happens if you torque across two wide mating surfaces or just have one at a point, in fact just sketch it out and ask any carpenter what will happen, then ask him if it is "just theory" and see what they say if you refuse to believe it. It is unlikely that they will think in terms of torque or pressure, but it will be obvious to them what will happen.

-Cliff

its easy to see your point when you extend it to the extreme, but that still doesn't answer the question of which way is better in real life, or whether or not there is even a difference at all, to the extent that it is noticible.

Does a framelock from Strider or Emerson, that is built as designed, with a small, mayber 3mm contact patch, fail at noticibly less loads that a framelock built by CRK, which has a longer, maybe 10mm contact patch? Loads from torque or not, I don't really care.

That is the real question. In real life we are not dealing with an infinately small point of contact and not working with wood. We are working with a reletively small area of contact and a reletively large area. Is it enough to make a noticible difference when we are dealing with the stresses required to make steel and titanium fail?

 

[MrMojoRising]

can anyone tell me the difference in quality or features between the strider and the "Buck" Strider? i never see them in any of the stores around here and i hear a lot of talk about them. just a little curious....ty in advance!

Hey look!

The actual topic that started this thread!

 

[Hair]

You can roll your eyes all you'd like, but the discussion at hand is very much in line with the original topic.

The lock design in the real Striders is different than the lock design in the Buck/Striders (which happen to be more like the school of design used by Chris Reeve).

So in determining which school is more effective, we also find out whether the real Striders or the Buck Striders have better locks.

Try to keep up.

 

[STR]

I remind you that the PT knives by Strider seem to me to be akin to the ones with full or nearly full looking contact areas on the interface.

STR

 

[Cliff Stamp]

Yes, Cliff, and this proves the design is inferior how?

By defination, liner/integrals locks do not have to be that unstable as demonstrated by Joe and Steve, not all of them have to have that problem. So it is a clear admission of an inferior design.

Then how did you bend the lock on the SERE 2000 during batoning?

This isn't comparable to a hand spine whack as defined in the liner lock FAQ and as you described you performed in the above.

How have I bent the liner on some flea market knife during a spine wack?

In general when people discuss standards for $500 customs you don't apply the same criteria as you use on a flea market knife. Flea market knives can be so poorly constructed they can fail trivially. I used a lock back a few years ago which actually came apart during cutting a piece of french bread, now would you use this to argue that cutting a piece of bread tests the strength of a Strider and by passing this test made a meaningful statement about its lock strength - how would people react if Strider made this ad in Blade, however this is exactly what you just did in the above.

I have broken folders by spine impacts using a baton, this is because the impacts are of another magnitude to spine whacks, they are not relatable in the direct sense as they don't test the same attributes. Joe Talmadge has noted in great detail that he can cause locks to release with spine whacks which are very light, not very heavy at all. There is no damage to the lock, it just releases, it is a security issue. This can not be extended to the behavior of hitting the spine with a baton inducing impacts of more than 50 in.lbs.

You have also broken locks that make full contact.

Because they fail differently at different points obviously. Full surfaces won't undergo point compression and will thus require more force to generate the necessary pressure, proportional to the contact ratio obviously. No this isn't the only failure mode, but it is a critical weakness of point contacts.

If this failure point was the only failure point, or even the weak link in the chain, then your proposed test would be very useful, but it isn't.

It is the weakpoint in the actual failure mode which is claimed to be the reason for the design, stability in vertical loads. If you think that somehow the wood model will give different results, it won't, the physical principles are the same, cut it out of sheet metal, or even hardened steel, the behavior will be the same in each, the forces just change (assuming of course you don't have irregularities like knots in the wood which should be obvious and you orientate the grain so it doesn't split and just compresses).

its easy to see your point when you extend it to the extreme, but that still doesn't answer the question of which way is better in real life, or whether or not there is even a difference at all, to the extent that it is noticible.

Now this is a different question, once you accept the problem of point compression as a reality and not a theoritical construct you can start the discussion of the significance, the pictures I have seen on some Strider engagements are much more than the 1:3 ratio you suggested so the difference in far more extreme. However if it is a functional weakness depends on the extent you intent to load the lock, it isn't trivial to compact hardened metals, even when they make light contact. I don't think it is possible to do it cutting, because even tighly binding materials like wood won't actually grasp the blade so tightly so you are talking about batoning usually.

-Cliff

 

[beefangusbeef]

I may be a weanie but I've never had a liner lock or any lock fail on me. If the going gets tough I pick up something government owned and pry with it!

 

[Hair]

By defination, liner/integrals locks do not have to be that unstable as demonstrated by Joe and Steve, not all of them have to have that problem. So it is a clear admission of an inferior design.

You had a bad Strider, and they wouldn't talk to you about it, so that means the design is inferior? What about all of the good Striders? What about the bad examples from other brands. Again, I have to ask how you are proving the design is faulty.

This isn't comparable to a hand spine whack as defined in the liner lock FAQ and as you described you performed in the above.

I never said spinewacks and batoning were the same. But you said strength is rarely an issue with liner locks. I disagree, and your tests seem to disagree as well.

In general when people discuss standards for $500 customs you don't apply the same criteria as you use on a flea market knife. Flea market knives can be so poorly constructed they can fail trivially. I used a lock back a few years ago which actually came apart during cutting a piece of french bread, now would you use this to argue that cutting a piece of bread tests the strength of a Strider and by passing this test made a meaningful statement about its lock strength - how would people react if Strider made this ad in Blade, however this is exactly what you just did in the above.

So the spinewack doesn't test strength unless the knife is below a certain standard? Or is it that the spineack doesn't test strength unless the knife isn't strong enough to pass? Yes Cliff, cutting frenchbread can be a test of strength, but it is a very light one. I doubt very many people would cut bread to test their knife's strength, but a spinewack is a common test, not just of security, but of the strength of the parts. But I guess you are going to tell *me* why *I* do spinewack tests.

I have broken folders by spine impacts using a baton, this is because the impacts are of another magnitude to spine whacks, they are not relatable in the direct sense as they don't test the same attributes. Joe Talmadge has noted in great detail that he can cause locks to release with spine whacks which are very light, not very heavy at all. There is no damage to the lock, it just releases, it is a security issue. This can not be extended to the behavior of hitting the spine with a baton inducing impacts of more than 50 in.lbs.

Surviving a test doesn't mean the test wasn't a test. So a spinewack doesn't test strength unless it is a very hard spinewack? Say, beyond a arbitrary about of force such as 50 in/lbs? Who decided at what force it becomes a test of strength? You? Who said my spinewacks were lighter than your batoning?

Because they fail differently at different points obviously. Full surfaces won't undergo point compression and will thus require more force to generate the necessary pressure, proportional to the contact ratio obviously. No this isn't the only failure mode, but it is a critical weakness of point contacts.

But I thought you said the main weakness of liner and framelocks was security, not strength? Strider says their lock design is in the interest of security, though obviously at the cost of some strength. It is a compromise. Does the end justify the means? That is what I am wondering. Telling me that there is a downside does no good. We all know there is a downside. But the supposed upside is more security, which you said was the primary concern with liner and framelocks, not the strength issue which you seem to be so unsure about with wooden Strider models.

It is the weakpoint in the actual failure mode which is claimed to be the reason for the design, stability in vertical loads. If you think that somehow the wood model will give different results, it won't, the physical principles are the same, cut it out of sheet metal, or even hardened steel, the behavior will be the same in each, the forces just change (assuming of course you don't have irregularities like knots in the wood which should be obvious and you orientate the grain so it doesn't split and just compresses).

It will give different results, Cliff. We are not trying to determine how strong a given lock is. We are comparing it to another lock. Of course the Strider lock will fail at some point- all locks will. If you make a model lock out of wood, it will fail at some point too. So telling us that a wood Strider lock will fail does no good. The issue at hand is which type of lock is better. Maybe a wood Sebenza lock would slip before the wood Strider lock would split. *THAT* is the question, Cliff. Not whether it will fail, but which will fail first. Starting to see your error?

 

[Cliff Stamp]

You had a bad Strider, and they wouldn't talk to you about it, so that means the design is inferior?

No, there was a public statement that the performance I saw was expected from Mick Strider, not that the knife was defective.

So the spinewack doesn't test strength unless the knife is below a certain standard?

In general to say something is tested by a task implies a level of significance and therefore it is meaningful to pass and allows discrimination based on performance and can therefore judge quality. Thus it isn't a test of edge retention to just cut one piece of hemp rope because it is trivially passed, even by mild steel.

As for who defines the standards, benchmarks by other knives as with all aspects of performance. A spine whack won't induce a strength failure, or even approach a fraction of the load required to do so, on any knife in Strider's class so it can't be used to discriminate knives based on strength, except in the grossest sense.

Who said my spinewacks were lighter than your batoning?

You can't physically rotate a blade so fast and so rigid in hand that the resulting impact energy would be similar because it is so much lighter than the batons I was using. 50 in.lbs isn't a force it is an energy, batoning typically starts to separate locks dramatically at about 25 ft.lbs, 50 ft.lbs was what I meant in the above. Spine whacks are not even in the same magnitude of impact energy.

But I thought you said the main weakness of liner and framelocks was security, not strength?

Generally yes, this isn't my idea, as noted the founding work was by Swaim and Talmadge, and it was an issue of releases not fracture or deformation. Harvey extended the work to such an extreme level that it could include strength as a failure mode as he would load the locks heavy enough to break them by attaching the folders to sticks and using full force impacts on hard targets, he was coming from a martial perspective and needed strength beyond what you would want just for utility cutting. Very few people are so demanding, recently Ritter has promoted similar use, though likely not to the same level as Harvey with batoning for splitting wood for "survival" folders.

Strider says their lock design is in the interest of security ...

The arguement about the triangle is one of torques and is a strength perspective mainly, as the contact points are further apart under the apex points it takes more force to rock the blade. This however doesn't consider compression at high pressure and that as you radically reduce the contact area this pressure will come at lower forces which reduces the strength. Note the arguement is typically often stated as the lock should meet at a point which would generate extreme contact pressure. As STR has noted, the mating length isn't consistent in Strider's folders, regardless of the assertion of point contacts, so it isn't though a comparison of those vs something which does try to mate at full length would be consistent.

Maybe a wood Sebenza lock would slip before the wood Strider lock would split.

The mode of failure being discussed was compression of the point contact, there won't be any slipping in that mode. Security in general is hard to pin down, note the work done by Swaim, Talmadge and Harvey were often on locks of the same design but did not get consistent security results. It would have been informative to have STR around to examine the locks which failed to see if a correlation could be made between actual design elements associated with releases and was it just poor implementation or specific design attributes. Some have argued that it is a vibration issue and that the liners jump off of the tang in impacts due to various elements of construction, and that torque failures are due to insufficient stiffness of the handle/pivot construction. It is a complex issue and the real problem was the lack of detail on the lock when problems were reported.

-Cliff

 

[lwsii]

I'm late responding to this, but I have to reply to STR's comment regarding Terzuola lock fit. I don't doubt he has handled more than I, but I own 7 & the only one which ever has/had any lock up play is the first one I bought (and it was used from Phil Fallon) in 1988 and have carried daily since then except for 3 days in 2003 when I overnited it to Bob (& he overnited it back the very next day). He tightened it,cleaned it up and didn't even charge to send it back NDA. Just my .02 cents, but it sure meant & still means a lot to me.

 

[STR]

I appreciate you bringing this up actually. I've felt bad about that since saying it but it is the truth. I have worked on them for lots of play. Its like I said somewhere here, I rarely see them when in their ideal or pristine state when they are sent for a repair. I probably should not have said that in hind site because I'm sure it is a rarity and just coincidence that I have seen some of his knives more than others. If nothing else it indicates they get used.

As for the service he gave you. Hey if I spent that kind of money for a folder it better come with exemplary service as you describe. That should be a given for any $150 to $200 knife let alone a $500 or $600 one or more.

Thanks

STR