Liner lock for self defense knife?

[Michael Janich]

First of all, thanks to everyone for a great thread and a great discussion. This is another example of why the Spyderco forums are the best around.

In my opinion, there are three elements to the design of any knife: the design concept itself, the engineering of that concept, and the execution of that engineering in production. If any one of these is flawed, the knife doesn't live up to its full potential.

When it comes to liner locks, Spyderco has learned from the very best in the business--including years of our own experience and diligent R&D. There are many minor details to the execution of a Spyderco liner lock that set it apart from the competition. Those details shine when it comes to both the operation of the knife and the scientific lock testing that Spyderco does on every model (I'm familiar with that, since the testing machine happens to be right next to my office. Whenever we test, I scurry over to watch...).

With all that said, most Spyderco liner locks are designed as utility tools with ease of use in mind. The relief cut on the obverse-side handle that allows the lock to be released provides easy operation of the release--even with gloved hands.

From a self-defense perspective, the potential disadvantage of the relief cut is that, if the knife twists in the hand during a violent maneuver, the index finger could contact the lock release and allow the blade to close. This is not a lock failure; it is an unintentional lock release during the dynamics of a critical incident.

For this reason, I do not consider the Sage 1 an ideal choice as a self-defense knife. The Sage II, however, is different. The Reeve Integral Lock is unique in that the tighter you squeeze the handle, the more you "cinch" the lock. Per the Sage project concept, the Sage II is exactly the same profile as the Sage I, just with a different lock.

I like the Sage II a lot and would have no qualms about carrying it as a defensive folder. In fact, I chose it as part of a special project I'm working on for American Handgunner paying homage to the S&W Centennial J-frame and its progenitor, Col. Rex Applegate's "lemon squeezer" .38. The Sage II and the Centennial are both two-tone Cerakoted in black and tan... but that's another story.

The only down side to the Sage II is the smooth titanium handle. Fortunately, there's an easy fix: Go down to the local hardware store and buy some of the textured rubber tape that you put in the bottom of your shower or on stair treads to provide traction. Skip the skateboard tape and go for the gray or white rubber. Use paper or posterboard to trim a decal panel to the desired size and shape to fit the non-clip side of the knife. Trace that to the back of the rubber tape and carefully cut it out. Clean the handle of your knife with alcohol and then carefully apply the tape decal. This method provides a great grip while leaving the clip side of the knife smooth for an easy draw. It works great on stainless handles too.

For the record, my favorite Spyderco liner lock for potential personal defense use is the Gayle Bradley. It is not only an exquisitely executed knife, but has a "flush ground" lock release that makes unintentional release of the lock almost impossible.

With all that said, if you're relly serious about self-defense, consider a Delica or Endura and a matching trainer. That way you can practice your skills safely with a trainer and you'll have the gear to actively pursue responsible hands-on training with a qualified instructor.

I hope this helps.

Stay safe,

Mike

[Blerv]

Random but you might also pick up some OC spray as a secondary option. My fox labs 2oz flip top rides in my dominant hand coat pocket and I walk with my hands in them anyway.

There are situations where range are nice and I'd rather gas an agressive panhandler than the alternative. That said, carrying a knife at all times is a great idea. Knowing how to use it is even better. Can't be too prepared :) .

Ps: I hear OC works mucht of the time on dogs too. Not that I would hold back on a red eyed pitbull but when fluffy gets off his leash he will be whimpering.

[224477]

From a self-defense perspective, the potential disadvantage of the relief cut is that, if the knife twists in the hand during a violent maneuver, the index finger could contact the lock release and allow the blade to close. This is not a lock failure; it is an unintentional lock release during the dynamics of a critical incident.

Well summed up Mike, and this is exactly why is stay away from linerlocks in general and especially for potential SD carry.

So far, I found that the best and relatively simplest to be done MBC lock is the compression lock, both left or right hand friendly and basically fool proof, as you would have to shear the screws off /stop pin or pivot/ first before the lock would fail.
Close second is the ball bearing lock, but there has been a couple of cases in the past with the Dodo when the ball slipped off the part of the tang of the blade, howevere very occasionally. I would say very much less than 1 of 100.

[Mr Blonde]

Well summed up Mike, and this is exactly why is stay away from linerlocks in general and especially for potential SD carry.

So far, I found that the best and relatively simplest to be done MBC lock is the compression lock, both left or right hand friendly and basically fool proof, as you would have to shear the screws off /stop pin or pivot/ first before the lock would fail.
Close second is the ball bearing lock, but there has been a couple of cases in the past with the Dodo when the ball slipped off the part of the tang of the blade, howevere very occasionally. I would say very much less than 1 of 100.

Amen on the comments regarding the cutout/access to the linerlock. I've had a Military close on my because of that (no cuts luckily), when I wasn't paying attention to what I was doing.

The Dodo problems you refer to seem to be restricted to the very first run of Dodos, when the tang (the part engaging the ball) was not tapered. All subsequent runs of models with ball locks had this problem solved, with tapered tangs.

Wouter

[stonyman]

One of the reasons I never obtained the venerable Military folder in the past was due to the preconceived notions of the liner lock. Mind you, the folks at Spyderco do it right. When the Ti RIL came around, that RIL lock......made the Mili leep into my hand. In handling drills and manipulations, the Milli framelock stood up! I have no reservations about strapping the Ti Milli on for serious social purposes. Deacon nailed it. Mike.......ditto! I will say all liners are not the same.......Framelocks, I like even more......spyderco framelocks.......win/win combination. If you cannot settle, there are plenty of other models in the lineup that can fill your needs. Take care and God Bless.

[The Deacon]

Well summed up Mike, and this is exactly why is stay away from linerlocks in general and especially for potential SD carry.

So far, I found that the best and relatively simplest to be done MBC lock is the compression lock, both left or right hand friendly and basically fool proof, as you would have to shear the screws off /stop pin or pivot/ first before the lock would fail.
Close second is the ball bearing lock, but there has been a couple of cases in the past with the Dodo when the ball slipped off the part of the tang of the blade, howevere very occasionally. I would say very much less than 1 of 100.

Funny, one of the things I dislike and distrust about the compression lock is that exposed release tab which sits directly under the first joint of my thumb more often than not. Seems like the proverbial accident waiting to happen. I'll stick with the devil I know - midlocks. :o

[chuck_roxas45]

How about the manix 2? will the caged ball lock be less prone to inadvertent lock release in SD situations?

[Reeper22]

Funny, one of the things I dislike and distrust about the compression lock is that exposed release tab which sits directly under the first joint of my thumb more often than not. Seems like the proverbial accident waiting to happen. I'll stick with the devil I know - midlocks. :o

The way I grip my Para I don't think I'd ever inadvertently release the comp lock. Are you left handed?

[jzmtl]

I have the same problem with compression lock, thou it's more how I hold the knife than left/right handed. I don't use choil on a knife unless necessary so my hand is more backward located, and the release tab tend to be right under my thumb.

[Erminio]

Interesting discussion - I used to believe the framelock was the safest one since my grip on the handle was keeping the frame in position, but now I wonder if twisting the knife in my hand could make my very grip to disengage the lock...I guess the best lock is no lock at all, i.e. a fixed blade.

Erminio

[chuck_roxas45]

Interesting discussion - I used to believe the framelock was the safest one since my grip on the handle was keeping the frame in position, but now I wonder if twisting the knife in my hand could make my very grip to disengage the lock...I guess the best lock is no lock at all, i.e. a fixed blade.

Erminio

of course, but sometimes you don't have the option of carrying an FB. so a folder is the next best thing.

[texcaliber]

The Sage II and the Centennial are both two-tone Cerakoted in black and tan... but that's another story.

To whom do I have to talk to, because I personally would love to hear about that story! Also I do not think I am the only one. Where Mr. Janich has the "New School, realistic and improved" aspect of defense (gun, edged, improvised or empty hand) the Col. is the "Godfather" and it is of interest to me.
Just let me know what I can do.

Thanks,
tex

[Bolster]

I can't speak about good liner locks, only bad ones. Purchased a linerlock years ago from a popular knife company, C***, and the darned thing defeated its lock, and folded across my fingers, cutting all four. So I don't even buy GOOD liner locks anymore. I stay away from all of them...personal prejudice, certainly unfounded for a high quality knife, but I stick to midlocks mostly. (I made an exception for a Lum, but I can't bring myself to use it. That knife just scares me sitting in the drawer...what's to keep my hand from sliding forward onto that wicked blade?) Looking forward to my first BB lock on a Manix! The BB lock inspires confidence, for me.

[defenestrate]

Bolstermanic,
I see no way for any of the Spyderco or even Byrd liner locks I've handled to fail without seriously abusing them, but I'm sure there are some model exceptions. Re: the CBBL on the Manix2, it is awesome! you will not be disappointed. Not only is it solid, but it has a huge range of openings that would be difficult to impossible on most if not all other lock types.

[SecSpyral]

How about the manix 2? will the caged ball lock be less prone to inadvertent lock release in SD situations?

The S90V Carbon Fiber Manix 2 I have is currently the best MBC option I have. It's a great knife with SOLID tank-like attributes

[PaloArt]

If I may add my opinion, I´m not too much liner lock fan for SD - only option as Mike J. pointed is ground flush liner lock as on gayle folder... my teacher of FMA asked Buddy Weston to make flush ground liner lock sd folders (pretty beasts :eek :) - decision for flush ground was actually that problem with accidental closing on for example spd Millie...

What I personally consider as good SD spyderco is delica and native III - I love that knife :p ... What I don´t understand is, how can Fred Perrin use such a little blades for SD (for example ladybug :D ) :eek: - what I´was taught was - bigger knife is better for SD - I know there are restrictions about blade lenght in many countries but those one or two inch blades as from Mr. Perrin??? He must be very very sure about his skills - no doubt about that... but seems absolutely unbelievable for my low skilled myself :p

[224477]

Funny, one of the things I dislike and distrust about the compression lock is that exposed release tab which sits directly under the first joint of my thumb more often than not. Seems like the proverbial accident waiting to happen. I'll stick with the devil I know - midlocks. :o

I place my thumb over the lock on the ramp, my grip must be different than yours. I hear you on the midlocks, but for the safest I would choose the comp over the midlock.

[SaturnNyne]

I used to believe the framelock was the safest one since my grip on the handle was keeping the frame in position, but now I wonder if twisting the knife in my hand could make my very grip to disengage the lock...

I suspected the same thing, and that's part of the reason I don't like frame locks. (The other part is that I just can't close them comfortably for some reason.) When I handled a friend's Chokwe I decided to test my theory by gripping the blade and pretending to make an aggressive (hard pressure and a tight grip) cut that involved upward pressure on the handle, such as might occur when whittling. I figured this would probably cause the lock to move a little and partially disengage, but I was a little surprised to find that it completely disengaged with very little effort. As I recall, the lock may have even bent and twisted enough under the pressure that I immediately stopped experimenting out of fear that I might damage it. I went in with a distrust of the lock, but I don't think what I found was too skewed by confirmation bias.

[chuck_roxas45]

I did try my military out. I gripped it with my usual right hand grip with my thumb on the jimping behind the hole and my index finger wrapped around the cutout. I then gripped the part of the handle protruding from my hand after the pinky with my left hand and twisted the whole thing in a clockwise direction. Lo and behold the solid as a vault liner lock released.

[bchan]

Interesting experiment, Chuck. I would think in a self-defense situation the person wielding a knife will more likely face resistance forces in a left-right (lateral) direction to parry the knife, and the risk of thus losing the grip of a linerlock or a framelock exists. That is why I prefer lockbacks for defense knives.