Spine Whacking....

Ken Cook · Nov 11, 2001

For a very long time I've been trying to convince people to stop "Spine Whacking" their knives. So I find it a pleasant surprise to find that REKAT agrees with me on this issue, but since I have never bought a REKAT (although I've wanted to, just never got around to it) I'd like to know. Does REKAT spell this out in the literature that goes out with their knives?

Is it clearly stated in the "Instructions" included with their knives that Spine Whacking is considered "abuse" of the knife?

medusaoblongata · Nov 11, 2001

Originally posted by Ken Cook
Does REKAT spell this out in the literature that goes out with their knives?

Is it clearly stated in the "Instructions" included with their knives that Spine Whacking is considered "abuse" of the knife?

REKAT knives (at least the ones I've bought) come with no literature or instructions, or paperwork whatsoever. If customers want info of any kind they have to go to REKAT's website - doh! I mean, they have to go to the REKAT forum. Uh-oh. Actually, this is the first I've heard of REKAT considering spine whacking abuse. They might have mentioned it elsewhere previously, but I haven't seen it.

Gator97 · Nov 11, 2001

Originally posted by Ken Cook

For a very long time I've been trying to convince people to stop "Spine Whacking" their knives. So I find it a pleasant surprise to find that REKAT agrees with me on this issue,
Ken, some time ago, there was a short video posted on EKI forum, remember that? Mr. Emerson with a knife vs. a guy with a button. The guy with a button hit the knife... Isn't that the same spine whack? What is your personal opinion? Should a combat and fighting knife withstand that sort of "abuse", or you'd rather agree that it is ok for the knife to fold on your fingers?

Does REKAT spell this out in the literature that goes out with their knives?

Is it clearly stated in the "Instructions" included with their knives that Spine Whacking is considered "abuse" of the knife?
I have 2 SIFUs, none came with any instructions. The one with D2 blade had a letter from 1SKS and that's it. And REKAT website has been down forever.

Ken Cook · Nov 11, 2001

Hi Gator,

Yes, I remember that video, here's the link to it on the EKI site...
http://www.emersonknives.com/videos/Training_Sticks.mpg

Notice that the title of the video is "Training Sticks" not "Knife Fighting."

Watch the video.
Ernie SLOWLY extends his Commander while he is still far outside of his striking range but well inside the striking range of his opponent. He then leaves the knife in a stationary position for just a moment, allowing his opponent to strike the knife.

(If you can "freeze frame" the image as the knife is knocked from his hand, you'll notice that even after the wicked blow from the training stick, the blade is still in the locked position.)

The truth is, if your fighting technique is as bad as what Ernie purposely did in that video, it doesn't matter what knife you have or how good it's lockup is, you're a dead man.

I duel with swords and daggers every single weekend, and my opponent never touches my blade with his unless I want him to. Ever. As a matter of fact, I even have time to orient the blade so that I take the blow with the flat of my blade, avoiding damage to my edges.

Now if I can do that with a 38 inch rapier blade and a 13 inch dagger blade, how hard can it be to avoid "combat spine whacks" in an actual confrontation? Answer is... It's pretty easy.

But let's run with your idea for a moment...

Do you slam your car into brick walls to see if it can take the stress of an actual car accident?

Do you throw rocks at your home's windows to see if they can withstand actual hail?

Of course not.
Why not?

Because it would be foolish to un-necessarily "pre-stress" your "equipment." Why give it battle damage before you ever even get into battle?

Yes, I'll concede that it's remotely possible that your knife may take a hard blow to the spine in an actual fight. It's possible. Highly unlikely, but possible none the less.

So accepting that possibility, why pre-stress a lock that may only stand up to ONE hard blow before you ever get to the fight?

Yet people continue to spine whack their knives.

If you want to test the lock strength of your knife, then do it reasonably.
WHILE KEEPING YOUR FINGERS CLEAR OF THE BLADE'S PATH
Hold the grip in one hand, and the blade in the other, gently apply force as if closing the knife. (without dis-engaging the lock)
If the lock moves, you have a problem. If it's rock solid, then there's no need to spine whack it, you've learned what you wanted to know without damaging the lockup.

Otherwise, if you're still that worried about the unlikely event of recieving a blow to the blade spine in a fight and you still don't have confidence in your knife's lockup, take my advice.

1. Get more training so that your blade spine is not such an easy target.
2. Buy a Balisong or a fixed blade.

Thanks for the info on REKAT's literature. (Or lack thereof)

Gator97 · Nov 12, 2001

Hi Ken,

Originally posted by Ken Cook

(If you can "freeze frame" the image as the knife is knocked from his hand, you'll notice that even after the wicked blow from the training stick, the blade is still in the locked position.)
Yes, that was my point. It didn't fail.

I duel with swords and daggers every single weekend, and my opponent never touches my blade with his unless I want him to. Ever.

Never? Ok, as you say. Accidents happen though.

As a matter of fact, I even have time to orient the blade so that I take the blow with the flat of my blade, avoiding damage to my edges.
Well, I used to practice fencing, but that was a long time ago, anyway, from what you are saying looks like you're better than your opponent. In other case you may not have that time.

how hard can it be to avoid "combat spine whacks" in an actual confrontation? Answer is... It's pretty easy.
Honestly I do not now. Because of the stress in the combat situation.
May not be a perfect example, but... I love my Desert Eagle pistol. It's a lot of fun to shoot, very accurate, and once U know how to shoot it properly it's a pure pleasure. In any caliber. Will I take it into combat? No. Even though I can shoot it quite good at the shooting range I am not sure if I can do the same in actual combat.
I screw up with shooting techniques, and it may jam. Am I willing to take that risk? No. However I'll never say that DE is a bad gun, it's a great gun. Just I know what can I do with it, and what I can not.
If you can act equally cold blooded in combat and in training, my sincere congrats. That takes a lot to achieve.

Do you slam your car into brick walls to see if it can take the stress of an actual car accident?

No, I don't(knocking on the wood), but the manufacturers do for me and you. Every single model of any car officially allowed for sale in US has to pass the safety test. Not sure about the numbers, but it MUST be more than 1. Slamming into the brick walls, and by steel blocks, etc. Why? The same, safety.
Is this reasonable? I think it is. And, please note, slamming into concrete walls is not a designed use of the car, just accidents happen unfortunately, and it doesn't necessarily mean that you have to end up dead because you slammed into the concrete wall. I bet you wouldn't throw away a chance to stay alive in that case, would you?

So, back to knives, since there are no official tests of what kind of loads and abuse/use a folding knife lock should withstand, people do that. I don't think it's surprising. Or then the manufacturer should warn against that.
If I know that knife X can't withstand spine whack I won't consider it fir combat, may be for the utility use, I know many will disagree on that one too, but it's a matter of opinion.

Of course not.
As you can see it's not that simple.

Because it would be foolish to un-necessarily "pre-stress" your "equipment." Why give it battle damage before you ever even get into battle?
Totally disagree. Take a look at aviation. Once the new model is designed they stress test it, till it falls apart. Why? So you know what it can do, find a problem(s), flaws in design, etc. Hoe else would you know?
What you are proposing is to go to the battle with what? Numbers on the paper? From what I know something like that happened already with M16 rifle if I am not mistaken, it had jamming problems, which was revealed in Vietnam? In general, any time, not well tested weapons wre used in combat that always costed lives.

Yes, I'll concede that it's remotely possible that your knife may take a hard blow to the spine in an actual fight. It's possible. Highly unlikely, but possible none the less.
Which is more possible, to get involved in car accident, or to receive a hard blow on the blade in a knife fight?

So accepting that possibility, why pre-stress a lock that may only stand up to ONE hard blow before you ever get to the fight?
It's not about enjoying pre stressing

First of all, where you get one blow you may get another one, then what? You deserve your fingers cut off, because you let it happen? Apply the same logic to the cars, and since you hit the wall UR better off dead?

Yet people continue to spine whack their knives.

Cars, airplanes, jet fighters, tanks, etc...

If you want to test the lock strength of your knife, then do it reasonably.
Agree, but it's very hard to define what is reasonable criteria for a combat knife. No matter how well trained you are, you can't predict everything, never.

gently apply force as if closing the knife. (without dis-engaging the lock)
Gently... I think the physics are different when the force is applied not gently, but by the impact. And in the knife fight chances are both will happen. And, again, you extrapolate. might cost dearly.

1. Get more training so that your blade spine is not such an easy target.
Well, that's useful regardless the knife used, right?

2. Buy a Balisong or a fixed blade.
Balisong is not an option here in CA, and fixed blades are problematic to carry in public... Which leaves us with the folders.

Ken Cook · Nov 12, 2001

Well, I used to practice fencing, but that was a long time ago, anyway, from what you are saying looks like you're better than your opponent. In other case you may not have that time.

As a point of clarification, I don't fence. I have no use for the over-glorified car antennas that fencers use. I use real blades with dulled edges and blunted point.

I also fight opponents from a pool of about 20 people. Never the same people two weeks in a row. I'm not the best, I'm actually ranked about third in the group right now. The swordsmen/women ranked under me are still a hard fight. The skill level overall is pretty close between 1st and 6th or 7th place. We've all been at it about the same amount of time. (several years.)

Take a look at aviation. Once the new model is designed they stress test it, till it falls apart. Why? So you know what it can do, find a problem(s), flaws in design, etc. Hoe else would you know?

Sorry, I'm not going to let you get away with the manufacturer's testing example, it doesn't relate.

Yes, they destruction test cars, aircraft all sorts of things.
They slam cars into brick walls, but they DO NOT then turn around and sell that car to an end-user. They scrap it. Why? Because it's no longer fit to be sold, it's damaged goods! But you seem to think that if you do the damage yourself, the knife is still okay.
I disagree.

Which is more possible, to get involved in car accident, or to receive a hard blow on the blade in a knife fight?

Getting into a car accident. I don't get your point here.

...but it's very hard to define what is reasonable criteria for a combat knife. No matter how well trained you are, you can't predict everything, never..."

That's very true.

Gently... I think the physics are different when the force is applied not gently, but by the impact. And in the knife fight chances are both will happen. And, again, you extrapolate. might cost dearly.

Of course the physics are different, but the point is, you apply stress without causing damage to not a test knife that will be disposed of, but YOUR knife, that you intend to carry for self defense.
Yes, I extrapolate. So do you. Do you honestly consider the Spine Whack Test to be a quantitive and reliable test of your equipment?

How many foot pounds of energy were in each "whack" you submitted your knife to?

How much torque was imparted to the lock?

How many thousandths did the lock flex at the moment of impact?

How closely does your casual whack correspond to the impact it would take from an unknown weapon of unknown mass traveling at an unknown speed?

The answer of course, is that you don't know! You have no idea and no way of telling.
Short of contracting out to Underwriter's Laboratory, you'll never know, and I promise you, that any knife you send to UL will come back to you with a lengthy lawyer's statement telling you that your knife is no longer usable and that they will not be held responsible if you should choose to use it.
In short, you would have paid good money, and gotten back a knife you still couldn't "trust."

The Spine Whack Test has NO substantive value as a means of determining even relative lock strength. It serves no purpose other than to create a (perhaps false) sense of confidence and to impart damage to your knife's vital locking mechanism.

When you spine whack your knives, you're paying a price and getting nothing of any real value back for your money.

I'd say that's a "Bad Deal."

SIFU1A · Nov 12, 2001

have bought 2 sifu's, neither one had any info w/it - i think a knife should be able to withstand a GENTLE whack on the spine and not fail, i mean, jeez, rolling locks are supposedly so strong, but it will break 'em to GENTLY whack the spine?? if the lock fails, and , heaven forbid ya are forced to stab something, and something has on a thick coat, body armor, etc, i want the thing to go thru the material, NOT fold up on me and cut the heck out of ME!! how else, pray tell, can ya establish the fact that the knife is locking up correctly?? (and people say liner locks suck lol)

my sifu, one day, while i was sharpening it, just closed up on me, cut the heck outta my fingers, did not inspire confidence for sure - if i need a knife it means the glocks, etc didnt work, and the last thing i need is to be worrying about the thing folding up on me - i have never carried the knife w/any confidence since it failed, and, i have 35+ folders, emerson, BM, spydie, Buck, microtech, cold steel, MOD and have NEVER had lock probs with ANY of them except a CRKT kasper, cost me about $45, and they immediatly fixed it, said nothing about spine whacking being abuse, etc and the new CRKT kasper passes w/flying colors..........

so, if i understand it, the high $$ REKAT knife will break if spine whacked, w/its bad to the bone rolling lock, BUT a $45 CRKT will pass the test, and isnt considered abuse by CRKT??

am i the only one who finds this strange?????

not to beat a dead horse, but some say liner locks suck???? go figure lol

sifu

(if this continues, i wanna change my name)

Tonie · Nov 12, 2001

You know Ken, I wonder just how much spine whacking it takes to be abuse when Bob Taylor has used it as a quality assurance test?

When I first found that my NIB Sifu would fold up under the feather light pressure of tapping the back of the point on the palm of my bare hand, I immediately assumed that this was an anomaly and sent it back. I called them to explain why and even enclosed a letter fully explaining the situation. Very shortly thereafter, I found a message on my phone. It was Bob T. telling me that my Sifu had been taken apart and had passed a full inspection and that it was in perfect shape. He even told me that he was performing the spine whack test even as he was leaving the message. And sure enough, I could hear him banging my knife on something in the background! When I got my knife back there were several very noticeable dings in the back of the blade from where it had impacted whatever Bob T. had been pounding it on.

Sadly, it still folded up with the slightest impact to the point.

If any amount of spine whacking is considered abuse, then not only did REKAT abuse my Sifu, but they sent it back damaged as well.

One of the reasons I registered here at BF was the presence of the REKAT Forum. I will miss this place if for nothing else how so many of the REKAT fans have taken so much effort to gather and share REKAT info with us. REKAT has some of the most innovative and effective combat knife designs on the market. I hope they can get past their present issues, including the lack of a website, and get on with business.

callahwj · Nov 12, 2001

off topic, but why does everyone think that that vid on the emerson site represents a typical combat situation? I've seen that used by so many people to criticize emerson, liner locks, folders in general, everything!

glockman99 · Nov 12, 2001

I might be off-base here, but I've been thinking...How many of these spine-wack "failures" of the Sifu (rolling-lock) MIGHT have been the result of the un-locking "slider" being moved inadvertently during these "tests"? (Could THAT be the cause of many of these reported "failures" of the rolling-lock?).

And for the record...I have never had ANY of MY REKATS fail ANY type of "test".

.

Samurai6 · Nov 12, 2001

Sorry. I will not stop spine whacking my folding knives. This test showed me which knives could take it, and therefore it is invaluable to me. I can understand if it voids the warranty, but that is not nearly as important to me as my fingers, so I will continue to test folding knives in this fashion. I have never sent a knife back for warranty repair afterward, but then, I have never bought eight knives and had them all fail in an unsatisfactory way. My BF Sifu passed all the tests and performed reliebly during a fair amount of dummy practice which included regular back cuts with the tip of the blade. Have not tested my current carbon fiber Sifu yet though.

Quit dissecting that video clip. If you do you miss the point. I linked to that clip on the Practical Tactical forum originally, simply to illustrate the sort of abuse that a folding fighter might need to withstand. The fact that the video is an advert for a fighting stick makes it even more germane. It says that if you go up against a stick fighter with a knife, this is what may happen, in fact is one of the most likely things to happen, especially with a folder with a big blade making an easy target. The rest of the details of it are unimportant. It was just an advertisment, and was not meant to be realistic in anything but the broadest sense.

Speaking as a stick fighter and a knife fighter, there is no arguing the fact that if you carry a folding knife for personal defense, it would really be an advantage to you if the knife can withstand a good hearty whack on the blade spine. If none of them could take it, it would be useless, but the fact is, some of them can, and if you are going to bet your life on a knife, it is good to know which side of the line your knife is on.

What I cannot understand is people who apologize for locking folders the locks of which do not work under the conditions in which you really need them. When closing pressure is applied to the spine of a locking folder that claims to be a "tactical" folder the lock should break before it ever releases. If the lock breaks, then you can say it was over-stressed, abused. Then the manufacturer could say, with honesty and integrity, that the knife was not designed to withstand that much force, or they could redesign their lock for more strength. If the lock simply releases, with no obvious damage, it isn't up to the rigors of CQC, may even be dangerous to use for utility in tight places where the user himself might accidentally bump the blade against a fixed object.

Tonie · Nov 12, 2001

G-man 99,

That's a fair enough question. I know mine occurred without any contact with the slide release whatsoever. Maybe one could posit that turning the knife upside down allowed the slide to actuate and release the lock.

You could posit that, but I doubt it. That in itself would be a huge design flaw and I doubt that Bob and Bob are capable of making that kind of mistake. No, I think it's more realistic to believe that the constant pressure -vs- light tapping on the back shows that you could not realistically expect the rolling lock on the Sifu to do something it wasn't designed to do.

Gator97 · Nov 12, 2001

Originally posted by Ken Cook

I have no use for the over-glorified car antennas that fencers use. I use real blades with dulled edges and blunted point.

Matter of opinion I guess. As of the use, less likely that you're using 38 inch sword on the street either. It's just a sport

Sorry, I'm not going to let you get away with the manufacturer's testing example, it doesn't relate.
In both cases we're talking about testing for safety reasons. Why it doesn't relate, because the car doesn't fold or what?

They slam cars into brick walls, but they DO NOT then turn around and sell that car to an end-user. They scrap it. Why? Because it's no longer fit to be sold, it's damaged goods!
Thanks, that was informative.

But you seem to think that if you do the damage yourself, the knife is still okay.
No, there's a difference which you ignore. Spine whack is something that is very likely to happen if you use it during combat and not only combat. Ok, you have your skills to avoid that, in training, and in combat as well

there are others who are not so sure about that, and therefore they want to be sure. Is that too hard to understand?

Of course the physics are different, but the point is, you apply stress without causing damage to not a test knife that will be disposed of, but YOUR knife, that you intend to carry for self defense.
The idea is to get the data the is relevant, or close at least. Gently applied force in no way shows what's gonna happen during the whack.

Yes, I extrapolate. So do you. Do you honestly consider the Spine Whack Test to be a quantitive and reliable test of your equipment?
Sure I do

The point is based on what data. To use "gentle force" data for impact result extrapolation is less credible, I think so...

How many foot pounds of energy were in each "whack" you submitted your knife to?
...
How closely does your casual whack correspond to the impact it would take from an unknown weapon of unknown mass traveling at an unknown speed?

I think there's no need to complicate that much. One msg in this thread stated that SIF had probs with light tap on the palm... Now, based on that data would you still have doubts that the same lock on that particular knife would fail on the harder impact?

The Spine Whack Test has NO substantive value as a means of determining even relative lock strength. It serves no purpose other than to create a (perhaps false) sense of confidence and to impart damage to your knife's vital locking mechanism.
As a mean of determining the relative lock strength it does have a real value. If you read the messages in this very thread you'd find some msgs that proove the point. Once again, since the manufacturer(s) do not provide any data people do their own tests.
I find your logic about damaging the lock that could withstand only 1 impact very questionable. If your blade receives that single impact then what, stop the fight or replace the blade?

Gator97 · Nov 12, 2001

Originally posted by callahwj

off topic, but why does everyone think that that vid on the emerson site represents a typical combat situation? I've seen that used by so many people to criticize emerson, liner locks, folders in general, everything!
I've mentioned that video as an example of what could potentially happen during the fight. Which doesn't mean that I consider it as a typical combat situation, nor I criticised Emerson or liners in this thread, confess, I've done that in other therads

Actually if you read that part regarding the video there was no criticism involved.

callahwj · Nov 12, 2001

Originally posted by Gator97

off topic, but why does everyone think that that vid on the emerson site represents a typical combat situation? I've seen that used by so many people to criticize emerson, liner locks, folders in general, everything!
I've mentioned that video as an example of what could potentially happen during the fight. Which doesn't mean that I consider it as a typical combat situation, nor I criticised Emerson or liners in this thread, confess, I've done that in other therads
Actually if you read that part regarding the video there was no criticism involved.

True. I'm sorry to put that all on you, but people bring up that video ALOT as the basis of various ideas. It can happen in combat, but, it's obvious that the video is there to showcase the training stick, and everyone likes to point at this one obscure less that ten second video and base their entire combat philosphy on it. Emerson could save themselves alot of inane criticism if they replaced it with 2 guys fighting with sticks...

J W Kilpatrick · Nov 12, 2001

SPARK, Thankyou for educating me on how the SIFU was designed. There was no such info with my SIFUS when I received them and Texas A & M did not offer a knife building course 101 in their college courses when I was enrolled there. I've only owned cold steel extra large voyagers in the past because they were big and dependable, at as far as my experiences with them. I went with cold steel products after viewing a video put out by Lynn Thompson showing how his knives could stand up to all sorts of abuse, even spine whacking. That's the kind of weapons I want to own ( those that can take a licking and keep on ticking). Well, when I found the blades forum and discovered the SIFU,I said that's the folder for me. So, when I got my SIFUS, I began comparing them to the performance of my cold steel knives thinking the SIFU should be able to stand up to the same kind of abuse as the cold steel knives. (I received no information from REKAT

saying that the Sifu would not stand up to the abuse of spine whacking). So, I proceeded onward with the spine whacking test to confirm that the SIFU could take a licking and keep on ticking since that's the kind of weapons I want to own. Well, I found 2 out of 8 SIFUS that passed the test and I am satisfied with them. I will sell the other 6 SIFUS at gun shows and caution people before buying them that if they are looking for a knife that will pass the spine whack test, that these 6 SIFUS are not the knives for them.
NOW, I need to issue a formal apology to Christina Montero and Bob Brothers and anyone else that I have offended by spine whacking the REKAT SIFU which is not designed to stand up to the absue of spine whacking. Also I want to clearly acknowledge that all 8 SIFUS passed with flying colors the constant steady pressure test that you described.
So, all this uproar was caused by my ignorance of not knowing what the SIFU was designed to do until you enlightened me by your recent post.I'm just an old army ranger who demands weapons that will function under the stress of combat. My sincerest apologies to all . It looks like me and Glockman have at least one thing in common. We each have 2 sifus that we can depend on.
Thankyou for the blades forum. I continue to receive an on going education about different types of knives here.

Ken Cook · Nov 12, 2001

I want to make clear that nothing in any of my posts was intended to either praise or damn the Sifu or any other specific knife.

My comments were addressed to the validity of the "Spine Whack Test" alone, and those came about only after I was asked to explain myself further. I had no intention of starting a debate and I have no illusions that I'm going to change a lot of minds about "Spine Whacking."

I think it's a mistake, others don't.
I can live with that.

Ken Cook · Nov 12, 2001

Parting thought...
As of the use, less likely that you're using 38 inch sword on the street either. It's just a sport"

The punk on the street won't think it's sport.

If you think the techniques don't apply to other things, you're missing a bet.

I train with sword and dagger, sword only, two swords, dagger only, two daggers, sword and cloak, buckler, whip, chain, etc...

I've never taken a lesson in FMA yet I've beaten an FMA Instructor without allowing him to ever land a single blow on me. a "Clean Kill" if you will. Does this mean I'm a badass?
No, it means the training is valid whether I carry a sword or a cane, or pick up a stick and a trashcan lid, or any one of a thousand variations. It's called flexibility.

Gator97 · Nov 12, 2001

Originally posted by Ken Cook

The punk on the street won't think it's sport.
? You carry 38 inch sword in the street

If you think the techniques don't apply to other things, you're missing a bet.
No, I was just thinking that fencing techniques can also be "applied"

Ken Cook · Nov 13, 2001

"? You carry 38 inch sword in the street"

To which I replied in part,
"No, it means the training is valid whether I carry a sword or a cane, or pick up a stick and a trashcan lid, or any one of a thousand variations. It's called flexibility."

At this point I have to assume you're being intentionally obtuse, and since I have no desire to argue for the sake of argument, thus ends my participation in this thread.

Spine Whacking....

RIP Dann, you were a good guy.