Disadvantages and longevity of the compression lock

U

ukknifer

Joined
Jan 30, 2010
Messages
424
Hi All,

I am thinking of picking up a paramilitart2 from spyderco. I have not had any compression lock on a folder before. I have 2 questions:

1- Will the compression lock have the same longevity of a liner lock with same use? Or is there more/less wear on the lock?

2- Are there any disadvantages of this lock type?

Thanks
 
I have around 8 knives with the compression lock, 3 of them get heavy use. The longevity of the lock will be the same as any other knife in terms of regular use should see the lock probably outlive you. Absure on the other hand will shorten the lifespan of jst about anything.

As far as disadvantages are concerned, there are really none I can think of. The lock does not make me breakfast, that would be one definite disadvantage! :D :D
 
I'm just subscribing to this thread. I've heard of compression locks but don't know what they are, how they work, what they look like etc.. :confused:
 
I think it's just like a linerlock.
Only problem i can think off it can take some time to get used to this way of lock.

I owned a yojimbo and a para with these locks and did like them:thumbup:.
But as i said i had to get used to them.
 
The compression lock will last longer then a liner lock (it is not a like a normal liner lock just turned around!!!) and is very strong. Even with some light bladeplay there will not be any problem with reliability. You will need to shear the stop pin out of the liners to have the lock fail I believe.

I hope this cross posting will be allowed but this is a good thread for you to have a look at the lock. Many changes have been done to the new PM2 then the one here (http://www.spyderco.com/forums/showthread.php?t=44324)
 
Only disadvantage seems to be a small number of reports of a little bladeplay. I can see how this could happen because the lock depends on an angled face and the spacing between the lockface and the pin matching up to the width of the lockbar.
 
*jijoel* said:
I think it's just like a linerlock.
Click to expand...

Not exactly.

It is a tab of metal that springs over like a liner lock, but it wedges between the blade tang and a pin. The tab of metal liner is then compressed between the stop pin and the tang...thus the name "compression".

The lock style is heavily touted as one of the more robust locks. If you understand how it works, it is pretty easy to conclude that it is going to be a hard lock to defeat.

Disadvantages are pretty much the same as any other fantastic lock I know of:
It may not work with your desired ergos
It may develop some blade play (though mine never have)
It may be difficult for you to actuate (particularly if you are lefthanded)


Nothing is forever, but if you really fear locks wearing out, stick with fixed blades...locks last a LONG time if properly designed/built/executed.
 
Here is a Horrid drawing I just did to attempt to illustrate how the lock works. The pink tab flips out and wedges itself between the tang and the pin. Hope this helps.

photo1ru.jpg


In reality the tang is shaped such that the vertical portion of the tang in the drawing hits the stop pin, this requires close tolerances and is hard to illustrate. Hopefully someone will post up images of a Para that has been disassembled to clarify?
 
unit said:
Here is a Horrid drawing I just did to attempt to illustrate how the lock works. The pink tab flips out and wedges itself between the tang and the pin. Hope this helps.

photo1ru.jpg


In reality the tang is shaped such that the vertical portion of the tang in the drawing hits the stop pin, this requires close tolerances and is hard to illustrate. Hopefully someone will post up images of a Para that has been disassembled to clarify?
Click to expand...

Man that drawing IS bad!:D
 
unit said:
Here is a Horrid drawing I just did to attempt to illustrate how the lock works. The pink tab flips out and wedges itself between the tang and the pin. Hope this helps.

photo1ru.jpg


In reality the tang is shaped such that the vertical portion of the tang in the drawing hits the stop pin, this requires close tolerances and is hard to illustrate. Hopefully someone will post up images of a Para that has been disassembled to clarify?
Click to expand...

WAIT.....I'm gonna guess....art major? :D
 
Unit , Thanks for taking the time to make that drawing :) It was enough to make me understand how the lock works .
 
The compression lock, like any lock, has pros and cons. I personally just can't seem to get used to it, and I find it much easier to release left-handed than right - and I'm right-handed. They also can pinch tender flesh between the lockleaf and the handle scale when you are opening the knife (not life-threatening, but somewhat annoying). The closed detent is weaker than I'm comfortable with on a tip-up knife. They flick open easily, but repeated inertial openings will peen the mating surfaces to the point of inducing bladeplay fairly quickly, as the amount of self-adjustment is not very large. And lastly, according to Sal Glesser (who invented it) they are a royal pain to get right, and there are very few makers that can do so.

On the plus side, even if it is beat to hell and sloppy, the lock is still very reliable. Most of them are rated very heavy duty, meaning the breaking strength is probably more than you can apply without a cheater bar. It is nearly impossible to defeat the lock without breaking something, and inadvertently releasing the lock would take a monumental screw-up.
 
Last edited:
ukknifer said:
Unit , Thanks for taking the time to make that drawing :) It was enough to make me understand how the lock works .
Click to expand...

Thanks, that is what I was going for.

I will be offering this piece and other knife sketches for sale in my art gallery for those interested:D
 
The compression lock is a very solid strong lock. The design is just ingenious. So strong yet so simple. Many of the "hard use" rated locks are somewhat complex with multiple moving parts. The compression lock has only one moving part, the lockbar. For a super reliable, simple, easy to clean lock it doesn't get much better. The only negative that I see is that its not a very ambidextrous lock. I can close it with either hand but when closing it in my left hand (I'm right handed) its pretty unwieldly.
 
No

In a liner lock, the liner is what takes all the force.

In a compression lock, the force is transfered to the stop pin.

In the Nagara, the push button just activates the liner lock. There is no stop pin action going on.
 
Disadvantages? Depending on position it may be hard to unlock. Yablanowitz found his Para hard to unlock while right-handed; I find it equally hard left-handed. The Superhawk is even worse.
 
marthinus said:
The compression lock will last longer then a liner lock (it is not a like a normal liner lock just turned around!!!) and is very strong. Even with some light bladeplay there will not be any problem with reliability. You will need to shear the stop pin out of the liners to have the lock fail I believe.

I hope this cross posting will be allowed but this is a good thread for you to have a look at the lock. Many changes have been done to the new PM2 then the one here (http://www.spyderco.com/forums/showthread.php?t=44324)
Click to expand...

I suport this. Bladeplay can be solved by screwing the pivot screws. Don´t know how, but this was done in a para passaround some years ago.
 
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