best lock and why

[Joe Talmadge]

Discussions as this one are many but never seem to cover the most obvious issue. When a knife is used, the forces aplied to it are directed to the edge. So if pure force alone would make the lock to collapse it would never fold in but further out or sideways.

That's true of gentleman's folder type usage, where the cutting can be carefully controlled. If that's how you use your knife, great]reliable[/b].

The blade folding back in is usualy a matter of accidental release instead of lockstrength. Still this seems to be what we are all so afraid of. Defining lockstrength should, in my oppinion, be measured in the direction in which the knife is used. Or are slipjoints the most dangerous tools on earth?

No, slipjoints are perfectly fine for light use or use where all cutting is controlled. Since many companies advertise many of their knives for much greater than light use, it behooves them to put a lock on it that is strong and reliable enough to handle the torques and uncontrolled forces that can be seen in tasks beyond opening mail and cutting twine.

Joe

[Joe Talmadge]

Reliability and strength aren't the only interesting features of a lock, of course. Two other factors:

- Ability to keep the blade in the handle: ball detente systems must be executed perfectly to work well, and provide just a little closing bias. Lock formats that use this type of system -- liner lock, frame lock, compression lock -- will be relatively more likely to open up in the pocket. Lock formats that have a spring providing closing bias tend to keep the blade in the handle. The backlock is the champ here, but axis lock, ball bearing lock, arc lock, etc. all provide some closing bias.

- Effect of pocket lint: Many folders will be carried in the pocket, which is full of lint. In my epxiernce, backlocks are the most susceptible to having problems due to lint -- if a piece of lint gets into the lock notch, the knife just won't lock up next time you take it out. This happened to me once or twice a year when I carried a backlock in the bottom of my pocket. Now I only carry them clipped to the pocket, so the pivot is well above the lint. All other lock formats can be affected by lint, but it's very rare in my experience.

[Mongo]

I would like to attest that, say you are a firefighters and you have to crawl into a smoldering carwreck, and use your ASSIST II to break the windows, then saw the remaining glass debrie out of the windowframe, and climb in the car, that's filling with smoke to cut loose a baby upside down in it's car seat, i want a knife that won't close on me should i trip, or when i brush the blade against the car seats crawling toward the rear bench.

Say you are a cop and you get called to a suicide, the guy is strangulating himself on the doorknob, still alive and you have to get your knife between the throat of the slowly suffocating wrestling victim, and the rope. Then you need a knife that won't collaps when forces are applied on the blade sideways, or on the spine etc.

What if you are a Police officer that's on his back while a criminal is banging his fists on the back of his head. I guess the cop can benefit from a knife that can still stab upside down. Even if the edge doesn't reaches the guy at least the sharpened point will reach the perp.

Or when you are a sailer, a fishermen, climber, or whitewater rafter,that gets caught in lines, you should need a knife with a blade that stays open, even if you have to "wiggle" it between your body and the rope.

just my 2 cents

[Joe Talmadge]

[quote="crahen"]
And that's not making a case against locks, just a case against abuse. Locks on GOOD quality knives should be more than strong enough to guard against accidental closing ]

Just to drive this point home ...

REgarding being "more than strong enough to guard against accidental closing" ... again, since almost any lock format can be made very strong, this is primarily a matter of reliability, not strength. That's a key point, which is why I repeat it like a recording. You're tackling a different problem if you start thinking of this as a strength issue.

In addition, regarding "just a case against abuse", in the context of your entire post, it sounds like you think forces directed in a direction other than edge-to-spine constitutes abuse. This is a case where it's easy to prove the contrary -- find me a single manufacturer who advertises his knives for defensive use or hard or even medium-duty use, and get him to support that statement. Let's ask Sal: Sal, if a Temperance Jr or ATR gets used in a defensive situation and is subject to uncontrolled torquing and sideways forces, is that "abuse", or is that something you design for since it's expected? If I'm cutting stiff cardboard with my endura and it binds up and I jiggle or torque it out, is that abuse, or something you feel the endura is designed and manufactured to withstand, and a failure might consitute a defect on Spyderco's part rather than abuse or misuse on my part?

Again, for you guys who use your knives only in very controlled cutting, then your lock requirements are different, and in fact a lock might not be required at all. But it's insulting for you to tell the rest of us that if we use the knife in a way that the manufacturer says it is designed for, that it's "abuse" or "misuse" or anything else. No responsible manufacturer making a knife for medium-use or harder would back you up on that -- in real life, in perfectly acceptable and predicable use, the blade can be subjected to side-to-side and torquing forces, and that's the way it is. If a knife is subject to the kind of torque that the knife is designed and intended for, then either the lock holds, or it's junk, and I'm sorry but trying to find some way to characterize it as abuse or misuse is misguided.

Joe

[wotanson]

Ball bearing lock for me, this lock will not fail imho! Nice that the lock is in my favorite :spyder: ie, the Dodo.

[ASmitty]

Ball bearing lock for me, this lock will not fail imho! Nice that the lock is in my favorite :spyder: ie, the Dodo.

I second that, Ball Bearing for me too.

[credit]

bearings seem to fail over time n almost all applications my 2cents

[crahen]

Just to drive this point home ...



In addition, regarding "just a case against abuse", in the context of your entire post, it sounds like you think forces directed in a direction other than edge-to-spine constitutes abuse. This is a case where it's easy to prove the contrary -- find me a single manufacturer who advertises his knives for defensive use or hard or even medium-duty use, and get him to support that statement. Let's ask Sal: Sal, if a Temperance Jr or ATR gets used in a defensive situation and is subject to uncontrolled torquing and sideways forces, is that "abuse", or is that something you design for since it's expected? If I'm cutting stiff cardboard with my endura and it binds up and I jiggle or torque it out, is that abuse, or something you feel the endura is designed and manufactured to withstand, and a failure might consitute a defect on Spyderco's part rather than abuse or misuse on my part?

Again, for you guys who use your knives only in very controlled cutting, then your lock requirements are different, and in fact a lock might not be required at all. But it's insulting for you to tell the rest of us that if we use the knife in a way that the manufacturer says it is designed for, that it's "abuse" or "misuse" or anything else. No responsible manufacturer making a knife for medium-use or harder would back you up on that -- in real life, in perfectly acceptable and predicable use, the blade can be subjected to side-to-side and torquing forces, and that's the way it is. If a knife is subject to the kind of torque that the knife is designed and intended for, then either the lock holds, or it's junk, and I'm sorry but trying to find some way to characterize it as abuse or misuse is misguided.

Joe

I think you misunderstood me Joe. Actually I basically agree with your arguement :D

Forces against the spine are secondary to the forces that are generally intended for knives. Knives are, first and foremost cutting tools. Therefore, a lock is to guard against "accidental" closing, at least that is what I believe the original intent was for a lock on a knife.

I'm sorry, no one was trying to "insult"( :confused: ) anyone else. If one needs a stong lock to guard against accidental closing as in the situations you point out, fine.

From the Spyderco warranty: "...does not cover damage caused by abuse, misuse, improper handling..." Is Spyderco using misguided terms?

But I still say too much fuss is made about how strong a particular lock is for "the average user".

Now lets get back to having fun with knives :D

[Joe Talmadge]

I think you misunderstood me Joe. Actually I basically agree with your arguement :D

Groovy :) But I'm still not sure you agree with me! See below. We're cool either way, I just get all nutty about this particular issue.

From the Spyderco warranty: "...does not cover damage caused by abuse, misuse, improper handling..." Is Spyderco using misguided terms?

Spyderco is using fine terms. However, the application of some torquing or other non-controlled pressure is neither abuse, nor misuse, nor improper handling, nor would Spyderco consider a knife that (say) got stuck in cardboard and failed when torqued out to be a knife that was subject to misuse, abuse, or whatever. When Spyderco talks about abuse or misuse, they certainly don't mean to apply it to all forces that aren't perfectly edge-to-spine, in fact that design knowing that their knives will be subject to these forces. It's the fact that you bring up these terms -- abuse, misuse, etc. -- in the context of this discussion about forces other than edge-to-spine that make me think we're not quite in agreement. Knives can and do get subjected to a lot of forces, and since some lock formats are particularly unreliable when subjected to those forces, I believe it's a reasonable concern for any knife user whose use is beyond opening envelopes and the like.

But I still say too much fuss is made about how strong a particular lock is for "the average user".

Well there I agree with you for sure. As I've been saying all along, it's reliability that's the issue, not strength, since the majority of failures are not catastrophic physical failures but locks simply slipping out of place. Reliability definitely is an issue, IMO, even for the average user.

Joe

[crahen]

Hi Joe!

I think we agree on more things than disagree :D

Just a big stupid misunderstanding, and of course me being WAAAY too sensitive :o

Shall we hug and make up :D :eek:

[denn]

you know, i said framelock at the beginning. but, yesterday during the preview show, i had the chance to handle many different framelocks, and i like to specify my opinion somewhat: i like them how it is on the karambit, with the little cutout on the left handlescale so you can actually REACH the bar. THAT is a good framelock. one that gets slippery or is hard to reach, well, i dunno....

come to think of it, i actually really like the good 'ol front-lock :)

[Piet.S]

I'm just trying to get us a clearer view on this matter Joe, let me try to be more specific. When measering the strengh of a knifelock, I think the first to test is its strengh in the direction of its intended use. In other words, holding the handle and apply force on the edge upwards. Second would be its resistance against folding in. So holding the handle and apply force on the spine downwards. Third would be pivot strengh, holding the handle and the blade and apply force on the pivot from the side. Fourth would be resistance against torsion, holding the handle and torque the blade. All these things are measerable and would give us a better idea of how strong a lock really is. And thus make them comparable. Now these tests are only static so dynamic testing is also something to give a thought. Something beyond spinewacking and again measerable. I just think that our current idea of lockstrengh is incomplete which leads to mistification. And also that the most important and first thing in this row should be, as I said before, on the edge upwards, hence my remark about slipjoints. Thats just how I feel about it, and yes I cut other things as paper.

[Sundown]

It's always cool to have guys as knowledgeable as Joe Talmadge sound in on topic like this! I must admit, Joe, I'm a big fan of your posts, here and elsewhere. Joe, Brownie, and Cliff are the guys who brought me back to lockbacks, and thus, back to Spyderco. Thanks, Joe! :)

[Joe Talmadge]

And also that the most important and first thing in this row should be, as I said before, on the edge upwards, hence my remark about slipjoints.

Okay, maybe my reading comprehension is bad, because that's not how I read your initial post. Put that way, ya, agree that there are other things beyond working against the lock that are of interest. Although I also think it is true that force against the lock is a common cause of failure and the most interesting to look at, but do agree that stresses in other directions are interesting. Now, what would be really interesting is to get a controlled test that worked against the lock while torquing or wiggling the blade, which would be more realistic.

Joe

[Joe Talmadge]

Thanks Sundown! Spyderco's lockbacks are really solid, good choice

[thombrogan]

Piet,

Those four tests would be good. I think that mixing torsion with the first four tests (upward, downward, leftward, rightward) and adding forward and rearward pressure (as though the knife were piercing a material or bound in a material) would also provide a good understanding.

Joe T,

I didn't know that the compression locks could let a little blade out to find fingers fishing in pockets. And then my new ATR exhibited that feature (luckily, it didn't bite me).

Deacon,

The nested compression lock on the Gunting is on the left side of the blade, but all other compression locks are made for left-handed use (don't tell Sal!) and their handles are made for tip-up deep carry with a reversible wire clip ala the Meerkat (please tell Sal!).

[Piet.S]

So now we have a concept for a series of tests to measure the strength of a knifelock, upwards, downwards, sideways and torque. And for reliability, safety, a combination of downwards and torque in a dynamic way. Adding lenghwise is also a possibility, though maybe for tactical knifes or real heavy users.
Question is, is this of any interrest to the knife world and Spyderco in particular? What do you all think.

[Rob]

Intersting thread. I for myself think the best lock is the one that works!

Every lock has it's pro's and con's but as long as it works (both technically and for the user) it's OK.

I prefer front locks for the ease of operation and I've never seen one failing in my hand.

Just my 2 cents...

Cheers, Rob