To Spine Whack, or Not to Spine Whack. That is the question

How many of us here were around in the days before folding knives locked that still have all ten fingers? :)

Anybody that spine whacks carry a slip joint? And what do you use it for? Cleaning under your nails, opening letters, etc.? Has it ever closed on you during use? Or were you super careful because you knew it didn't lock?

Just to go off on a tangent- how many of you regularly test the safety on a gun?

And how many of you that spine whack use guns that don't have a safety? Any single action revolver fans (pre-transfer bar vintage) that carry six up?

I'm not trying to start anything here, I'm just really curious. I don't spine whack, and I *never* trust the safety on *any* gun. I just assume it'll fail and act accordingly, i.e. finger off the trigger until I want it to go BANG!
 
Times move on Bimjo. No one today would consider carrying a slip-joint folder as a "tactical" knife , possibly as their primary self-defense weapon. Now days there are folders with locks that make them reasonable choices for tactical missions. The question is, which ones are most suitable.

You gun safety analogy is actually off target. Would you carry a pistol with a reputation for blowing up in your face when you fired it?
 
Steve, sorry, I missed the "tactical" flavor to the thread & can see your point.

In that vein, viewing a lock as part of a tactical package, I'd have to agree with your assessment that my analogy is off target.

Viewed in the "lock as a safety device" (as I was and didn't adequately communicate) I think it's still valid and the question stands.

And to answer your question- No, I wouldn't carry a pistol with a reputation for blowing up in your face when you fired it. Although I did actually have one do that once. That was fun. :eek:
 
Cerulean, that is too funny that the same thing happened to your eagle knife!

When mine did that I was in the process of moving into a new house and my brother was helping me. He is into knives too, so we were both rolling on the floor laughing when the thing broke! I said "hmmmm, it looks like this thing has developed quite a bit of vertical blade play" in my best scientific nerdy voice.

I still say that to him sometimes and we crack up again. Sometimes when I know I will run into him that day, I bring that poor old eagle and pull it out for a laugh. Ahh, good times, good times... :)
 
As KWM pointed out, REKAT does consider spine whacking their knives as abuse as indicated in the REKAT forum. Are there any makers or companies that feel the same?
 
How many spine whackers also crash test their autos/trucks like in those crash dummies ads? Aren't we more likely to be involved in an auto crash than be involved in a life threatening altercation involving a knife? Just wondering. ;)
 
Bimjo, you may be onto something here...

<b>Anybody that spine whacks carry a slip joint? And what do you use it for? Cleaning under your nails, opening letters, etc.? Has it ever closed on you during use? Or were you super careful because you knew it didn't lock?</b>

I don't carry a slipjoint, but I use all my folders as if they had no lock.

<b>Just to go off on a tangent- how many of you regularly test the safety on a gun?</b>

I CHECK the safeties on my guns every time I pick one up. I still never trust them though.

<b>And how many of you that spine whack use guns that don't have a safety? Any single action revolver fans (pre-transfer bar vintage) that carry six up?</b>

Oddly enough, I was handling my Colt SAA Clone while reading the post.
I never load six. Load one, skip one, load four. Always and forever.

<b>I'm not trying to start anything here, I'm just really curious. I don't spine whack, and I *never* trust the safety on *any* gun. I just assume it'll fail and act accordingly, i.e. finger off the trigger until I want it to go BANG!</b>

I think you've hit the nail on the head concerning the reason why so many are so opposed to spine whacking, and why so many are determined to do it.

It comes down to the question of trusting a mechanical safety.
I don't. I can't. I never will.

Mechanical devices fail, whether it's a liner lock or a thumb safety. Whether it's a transfer bar or a detent type lock, it doesn't matter.

Safety comes from the User, not the tool. There are those among us who have want to have faith in their mechanical safeties, and so they feel driven to test them. I do not trust mechanical safeties no matter how well they have performed in the past, for there is no guarantee that it will perform properly THIS time. Therefore, there's really no need to test it.

Spine whacking tells you what a lock did this time, not what it's going to do next time.

When I get a new Liner Lock, I lock the blade open, then try to close it as if it were a slip joint. I apply good hard pressure, and if there is no movement in the lockup, I call it good and I carry it. I've never had a Linerlock close up on me yet, and yes, I use my knives hard.
 
If Tactical Knives magazine were crash testing folder locks the way the NTSB and other bodies are crash testing cars, we would not be having this debate. If there were no safety oversight organizations investigating and setting standards for the safety of cars, would you ridicule independant testers for doing so?

Would you say, Aaaaaa, cars aren't meant to be crashed. Don't crash your car, and you won't have to worry about getting killed?

That analogy don't work.

Thanks Bimjo. Yes, it is mostly a tactical (or not tactical) issue. If you don't need a lock with impact reliability, then the spine whack test, at least at levels above a gentle tap, are not called for. I carry several smaller pocket knives, mostly lockbacks, but one liner lock also, and I don't really impact test those locks at all. There have been several reports though of people who were doing non-tactical cutting tasks, and accidentally hit the back of the blade on surrounding objects, resulting in accidental lock releases. One hit a branch on a back-swing while doing some gardening, one hit the knife against a chassis member while working under a car, and another hit his knife against a door frame subsequent to sharpening the knife. So there are needs for reliable locks even on knives that are not intended to serve as weapons.

REKAT has indeed now stated that impact testing the Rolling Lock is considered abuse. I cannot find any archived statements by Bob Brothers or Bob Taylor to support this, but I definately got the impression that those two did not consider it abuse, at least not on the Pioneer and Pocket Hobit folders. In fact the Pocket Hobbit design is based on using both sides of the blade. The curved and serrated spine is designed for hooking and trapping, activities that would almost guarantee strong impacts to the spine. I also have a foggy recollection of a discussion we had about the Sifu and back cutting when it first came out. I think Bob T. was involved in that discussion, and my impression was that back cutting was something that was within the performance profile of the Sifu. You definately need an impact resistant lock for that. So, as much as I am a fan of REKAT's products, I would have to say that considering it abuse to place closing pressure on the Rolling Lock is something quite new. But again, without documentation of statements by the REKAT Bobs, that is only based on my own impression.

I beat the kaka out of two Pioneers, a Pioneer and a Pioneer II. The older Pioneer would release occasionally, say one out of ten impacts, but the P-II has been undefeatable. I still carry the P-II myself, and the Pioneer is being carried by a friend. After testing both are quite solid and reliable.

Frankly, if I bought eight Sifus, and six of them collapsed under moderate testing, I would need evidence that the knives were damaged by the tests, or my money back, because I have never been able to detect any damage to a Rolling Lock resulting from my quite vigorous testing of them. They have always functioned just as well afterward as before, including the one that released occasionally.
 
I spine whack all of mine.
If a lock is crappy enough it can't take a decent whack on the back of the blade, it's going back to the manufacturer if it's worth the trouble, and the trash can if it's not.
 
Back to this same topic again.:rolleyes:

I am still trying to define my attitudes towards the deadly SWT. My current thinking is that moderate tapping or whacking is justifiable. I like the idea of striking the blade spine up against the palm of the free hand. It can be done fairly vigorously from different angles and should give a decent idea of the probability of lock failure. Moderate taps against a 2X4 or the like can also be useful.

What I disagree with are the advocates of "bashing" the spine strongly as I have heard some espouse around here. Rapping the spine 30 or more times against a workbench top at full speed is nothing less than knife-abuse, IMO. If you must do this, you need to be using a fixed blade. The resulting pivot wobble would or should not be covered by the warranty.

Bottom line? I'm still in a learning mode, but that's where my point of view is at this point.
 
I keep hearing the analogy: Do you spine whackers crash test your car by slamming it into a telephone pole etc...

For me that analogy doesn't make sense.If we were talking about putting the knife on a log and smashing it with a sledgehammer then it would make sense.
In my view a moderate whack should not destroy the knife so it really isn't like smashing a car into a telephone pole etc.I have been spinewhacking a Cqc-7 over the last 48 hours off and on and my knife is no worse for wear.Lockup is still good.i am guestimating about 2000 good solid whacks. I have moved from my wife's cutting board to a chunk of 2 by 12.Surely this knife is not like a car being slammed into a telephone pole.There is really no visible damage at all.
I still don't believe the spine whack is the greatest test in the world for a folder.My interest in the subject is the idea that a well executed and designed knife would not be able to handle a whack against the top of a desk without being ruined.That concept does not make sense to me.
troy
 
I don't spine whack, primarily because I personaly don't have a need for a super strong lock. I have no interest in tactical applications of knives. I am not likely to have as assailant "strike the back of my knife in a combat situation" or glance the blade off of some poor sucker's spine or rib, as others have suggested. However, I would prefer that it doesn't close up when I don't intend it to.

Therefore, for me a lock is more likely to fail because it doesn't engage right to begin with, rather than a post-opening impact. For this reason, I only use liner/frame locks because I can SEE that the lock is set, physicly occupying the space that the blade would have to occupy to fold. I don't get that with a lockback/axis/rolling/arc lock.

The best analogy that I can come up with is a car. To me, any of these locks is like leaving the car in "Park" while its running, an unseen mechanical failure could cause it to go. A liner/frame lock is like taking the key with you, virtually assuring that under normal circumstances there is no way the car is going anywhere.

Once again, this applies only for outdoor and utility use, I am sure that self defense or combat applications require a different kind of reliability, which is why a completely understand others' desire to spine whack. Like everything else, it is simply a matter of priorities.
 
on a linerlock you can't see if the liner is engaged while it is in your hand and you are using it.On my 710 axis you can look directly down on the locking bar while the knife is in use.It always stays engaged no matter what,but it is comforting to see the lock bar across the tang..
troy
 
If we want to use the car analogy, I think it would be akin to a bump rather than a full speed crash. You don't expect your car to fold up or fall apart if you were to bump an object at say... parking lot speeds. You might cause some damage to the bumper or side panels that may come back to haunt you if you encounter a full speed crash though, because the affected part may be slightly damaged. But you can definitely do quite a few more bumps to the car, even in the same spot, and expect it to hold up. And when it comes to a full speed crash, whether or not you have the light damage on your bumper or panels may not matter.

Similar to the parking lot bumps are light to moderate spine wack tests. Full on sledge hammer tests would be delibrately running your car in to a brick wall at high speed. Only you can decide how hard you want to test it and why. And then you have to realise the possible damage the knife might sustain.

And as a further analogy, I think Cliff might be one of those independent testers like NCRMA. :)
 
I guess I spine whack mine, but not to test the lock. I often grab my EDC and give it a good scrubbing while in the shower(use one of those nail brushes to get in the nook and crannys). And when I have finished said shower, I fold the towel in my hand and smack the knife into the towel. I don't hit it sharp side either, I'd slice my towels to shreds. In reality, I'm not putting any strain on the blade in a closing manner, I hit with the whole thing, so the force is spread out. Most likely putting the strain in the direction that its supposed to be. I do this to "knock" the water outta the piviot. Seems to work too.
 
I think a slightly better car analogy would be yanking the door handle to make _sure_ that the door won't open, should someone else give the door the same treatment...

Giving it a few moderate tugs when parking in an unfamiliar area isn't abuse; but pulling as hard as you can, repeatedly, every time you get out, is bound to wear out the handle (and get you strange looks from passers-by).
 
Originally posted by KWM
If a spine whack test is allowed how does the knife's maker then tell someone how hard they can hit the knife, and once the knife is returned to the maker/factory what kind of test is there to determine if the spine whack was done within the limits described in the warranty? I suppose it is easy to tell if someone used a sledgehammer, but it is more likely that it will not be that obvious.

You either have to allow the test, and that means allow for the possibility of the knife being abused, or not allow the test at all. For most manufacturers/makers the last choice makes the most sense.
Click to expand...
I think of it as a costumer service issue vs. a legal issue. Most companies WANT your money and good service is the best way to generate repeat business. So, if you call Knife Maker X and said the lock failed when the spine was hit, they should say “Send it in, we‘ll fix it!” Now if they return your call asking about a 1/4” DENT in the spine, they have the right to say the warranty was invalided.

It’s like on TV: “Don‘t do this at home kids,” you might get hurt. Nine times out of ten they don’t (or shouldn‘t ) mind the costumer “testing” the product. It’s the people you don’t understand “reasonable limits” that they make the disclaimer. (Too many lawyers does not help either)

Have you ever heard the saying; The costumer who demands the most, is the one who pays the least.

I have a $45-on-sale CS voyager, should I hold it to the same standards as a $345 Sebenza? No, you and I both know that, but the knife companies would go broke trying to please the morons who don’t!

On a final note, I’m in favor of insuring your knife works as expected. I like my knife because if I lose a knife fight to the fellow Marine out there who likes Sebenzas so much, I Know it won’t be because of the knife.
 
Brembo, did you say you were showering with your edc.??
That is paranoid kinky. Better try some peanut oil afterward to ward off rust..

I agree with a lot of points Joe and Don have made.
Near as I can tell Spine whacking is a term I first heard on the forum.
It is not a noun with a quantifiable nature but an adjective describing a general act.
Most "whackers" would consider a mere tap on the spine a fair test, I tap them on a mouse pad on my desk rather softly, cant see a manufacturer complain about that. However its a process of progressive forces and since not standardized eventually you will be able to destroy a lock.

Joe has suggested that whacking may help set a lock.
I think he may be on to something.
Personally I think a knife you intend to trust your life to should be tested once or twice. You need to be able to trust it will work a little at least.
If it passes, further tapping may be abuse, good point there...
However if it fails a light spine whack it is a system with a problem needing correction. The lock face and the high grade steels are differential materials with tight tolearances of fit and angle. If any of several factors is off the lock will not perform optimally. I think a big factor in some cases is the angle of the grind of the liner lock versus the blade locking surface. If they don't mesh at a good enough patch they slip.

Don, this is for you. The first time My EDI failed I was thinking about whacking while walking in the woods... Hee Hee hee.
Any way I just pullled the sucker out, held it as normal and put a little pressure on the back of the blade. Obviously expecting it to hold. It didn't and snapped over on my index finger. Nice little perforated line from those beautifull serrations.
After that I spine whacked it gently in a series about twenty or thirty times.
THe lock began to put up a little more resisitance. It still could slip but did seem to be holding better.
Last night I was cleaning some stuff and put a little Hoppes on it.
Now it will barely lock at all.

I think the EDI is one of the most beautiful knives I have.
I don't condemn its inability to pass the spine whack. However, Im sure glad I know its litmitations.
In a serious situation I can see this failure removing a finger quite easily. Especially while grappling, if you get thrown down with your weight on the knife with your finger pinned between the blade and its home... Don't you want to go into YOUR HOME?!!!
The knife is a machine with a delicate relationship of interrelated parts. Thats WHY I LOVE THEM.
In the EDIs case I think the ATS 34 blade hits the liner, possibly titanium, at minutely the wrong angle. Both are slanted. That is, not at 90 degreees as the benchmades I have are.
Nope, I take that back the Benchmades do seem to have a slant on the blade locking surface of the lock as well. But its less of an angle than the EDIs. This design requires an extremely tight tolerance which in this case appears to have been missed.
I think it could be fixed by removing the liner and changing the angle slightly but Im hesitant to do this. It could probably not be fixed by hours of spine whacking. But then again it might eventually wear off enough metal to fit tightly.
None of the other locks I have fail a mild spine tap.
THis is why I feel its a legitimate test, er past time, or whatever.
Blahh blahh blah
 
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