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What happened to the venerable and undersung Compression Lock?!

Posted: Fri Oct 23, 2009 1:11 am
by peacefuljeffrey
I'm at a loss. I have a Para Military, a Gunting, an Almite Salsa, and two Vesuviuses--these are Compression Lock folders, and I LOVE the Compression Lock!

I can't understand why more knives aren't made that way--and yet, Spyderco has released a number of new Liner Lock models in the time since the CL was released (particularly the Taiwanese models, I note).

Apart from the Ball Bearing Lock, I think that the Compression Lock is the best innovation ever in knife locks. I don't use my knives all that hard, especially not with regard to closing forces, so I have never bought into the whole "liner lock is too weak" argument. What I don't like about every liner lock that I've encountered is the fact that they rely on the ball-bearing detent, which I do not trust. It's too sensitive, often not strong enough, and relies far too much on precise tolerances. Oh, and there's the potential for eventual wear-out.

Now, give me a Para Military with a lock that holds the knife closed using a milled tang, and you put a big smile on my face.

What's the deal? Why weren't more CL knives made? Are there any to come? Or is it the HD DVD of the knife world--good, but eventually just not favored?

Posted: Fri Oct 23, 2009 1:15 am
by peacefuljeffrey
P.S. Centofante's Vesuvius is a gorrrrrgeous knife. Seriously underrated. Carries great, feels great, cuts great, LOOKS great!

Posted: Fri Oct 23, 2009 1:25 am
by th0m
This might be stupid, but I still don't get what the compression lock is. Anyone care to enlighten me?

Posted: Fri Oct 23, 2009 5:11 am
by The Mastiff
I don't think that all of the contractors can make the compression lock. Basicly scheduling time in the shops that can pull it off is what limits the number of knives that will be built with it.

If I'm not mistaken there are easier locks from a production and maybe price standpoint. That would be my educated guess recalling past statements from Sal.

Posted: Fri Oct 23, 2009 5:27 am
by Sequimite
I like the compression lock and judging by the number of Chinese knives featuring the compression lock, it may be harder than some but appears to be easier than most.

When I first used a compression lock, on a Paramilitary, I loved both the concept and ease of use. Having the tang interposed between the notch in the back of the blade and the stop pin seems intrinsically more secure to me, while retaining the open back and ease of use of the liner lock.

Posted: Fri Oct 23, 2009 5:49 am
by Clawhammer
th0m wrote:This might be stupid, but I still don't get what the compression lock is. Anyone care to enlighten me?
http://www.folders-r-us.org/full_terminology.htm
and Sal's patent pics
http://www.freepatentsonline.com/6553672.pdf

I guess the simplest way to explain is that it's got a 'springy' piece of metal that you push to the side to 'jam' the hinge...it's kind of like an upsidedown linerlock...quite clever really...I like how even to this day people keep coming up with new stuff!!!

Anyone please feel free to jump in if I'm wrong... I've never actualy had a comp.lock knife! ;)

Posted: Fri Oct 23, 2009 5:58 am
by Praxis
Sequimite wrote:I like the compression lock and judging by the number of Chinese knives featuring the compression lock, it may be harder than some but appears to be easier than most.
Maybe I'm completely out to lunch today, but what Chinese knives feature a compression lock? Can't think of a single one. I thought compression locks were a Golden product due to the tight tolerances for manufacturing? :confused:

Posted: Fri Oct 23, 2009 6:19 am
by Sequimite
I'm just about to close down my laptop and drive from Louisville to St. Louis, so I don't have time to post some examples.

The two non-Spyderco Chinese knives I own have compression locks that work perfectly well. I've seen Chinese copies that are pretty accurate but change the lock to a compression lock. When I mentioned this to someone at Spyderco, I was told that the Chinese knife-makers like the compression lock because it is so easy to make.

Now, one has to draw an important distinction between it being easy to make a compression lock and how difficult it may be to make a compression lock that meets Spyderco's standards.

Posted: Fri Oct 23, 2009 6:25 am
by iwolf81
peacefuljeffrey wrote:I have a Para Military, a Gunting, an Almite Salsa, and two Vesuviuses--these are Compression Lock folders, and I LOVE the Compression Lock!
You now need to get an ATR. When I exclaimed my appreciation for compression locks, another forum member told me about the ATR. From that point on I was hooked on Spyderco knives! :D

Regards,
Ira

Posted: Fri Oct 23, 2009 6:52 am
by The Deacon
One factor may be that, although there are several compression lock models with strong "afi" followings, none, except possibly the ParaMilitary, have done well enough in the general knife market to remain in the lineup for too long.

In my opinion, that could be one of two factors, or a combination of them, at work. I think it's reasonable to say that John Q Knifebuyer is somewhat more reluctant than "we" are to try new things. It also may not have helped that, to date, the models using it have, for the most part, not really been "mainstream" pieces. Some have even contained a double dose of "new", a cobra hood in addition to the compression lock.

The one closest to John Q's concept of a pocket knife would have been the Vesuvius. Unfortunately, like many first time implementations of a new concept, it was plagued with QC issues.

Posted: Fri Oct 23, 2009 7:13 am
by Michael Janich
The compression lock is alive and well--and like everything at Spyderco, is the subject of continued improvement and perfection.

I was stoked to have a compression lock on the Yojimbo. And as I am considering a potential second generation version of that design, the compression lock is a key component of it.

To clarify what it is mechanically, start with a liner lock concept. Traditionally, the ramp of the blade faces the butt of the knife when open and the face of the liner faces forward (toward the pivot pin) to engage the ramp and lock the blade open. A stop pin in the back of the handle serves the purpose of stopping the rotation of the blade to the open position and forms one of the three corners of the lock triangle.

On the compression lock, the ramp is actually cut out of the top rear of the tang so it faces upward when the blade is open. The liner arm is located in the back of the handle rather than the "slot" side into which the blade folds. When the blade is opened, the liner arm's spring tension moves it across the ramp laterally. The stop pin, which is positioned right above the ramp and liner arm, now not only stops the rotation of the blade, it also prevents any upward movement of the liner arm. As such, the liner arm is "compressed" between the stop pin and the ramp of the blade. Downward pressure on the back of the blade (attempting to close it) translates to upward pressure on the ramp, which is resisted by the width of the liner arm and the stop pin.

In addition to being one of the strongest folder locks, the compression lock also allows extremely safe one-handed closure of the blade, since the fingers do not cover the blade slot when the lock is released.

I hope this helps. Thanks for your enthusiasm for a great lock.

Stay safe,

Mike

Posted: Fri Oct 23, 2009 7:34 am
by Sam Vimes
Praxis wrote:Maybe I'm completely out to lunch today, but what Chinese knives feature a compression lock? Can't think of a single one. I thought compression locks were a Golden product due to the tight tolerances for manufacturing? :confused:
One foreign made compression lock knife springs to mind in the "S". However, that's made in Taiwan.

Posted: Fri Oct 23, 2009 7:45 am
by JLS
A Chinese example of a Compression Lock offspring is the Cherusker Messer/Bram Frank "Puzzle Lock". While it is NOT the same, it is conceptually very similar. I haven't found that is is made well enough to provide the same level of security as a Spyderco Compression Lock.

I'm glad you posted the patent link. There are quite a few implementations on there that haven't been used. It's good to see Spyderco is very serious about their patents and patent derivatives for protection even if they don't necessarily plan on using them.

Posted: Fri Oct 23, 2009 7:56 am
by demtek9
I'd rather have a US made compression lock knife. The tiawan version on the S is not so strong and has some give.

Posted: Fri Oct 23, 2009 8:13 am
by catamount
The Superhawk is another very nice compression lock :spyder: that doesn't get much love.

Image

Sal has said they have a design in the works that pairs the Superhawk handle & lock with a more mainstream blade shape.

Posted: Fri Oct 23, 2009 8:54 am
by bh49
I have few knives with compression lock and I like all of them. I wouldn't buy a knife just because of lock. There are several locks, which I like and it doesn't make a difference for me, at least at this time, which one of them the knife has.
Still my first experience with compression lock wasn't that positive: I wasn't sure what to buy: Lil T or Mini Manix. Went to the store to try both and determine that it is much easier to use lockback, still bought Lil T, just because it was already discontinued. After a little practice compression lock is great, but it took a few times to open and close. So some people can be turned off just by this.

Posted: Fri Oct 23, 2009 11:01 am
by jzmtl
Don't mean to rain on your parade but not everybody likes compression lock. You tend to get people who love something to be very vocal, but most likely not true indication of what the general population.

Posted: Fri Oct 23, 2009 11:45 am
by Brad S.
I as well am one that loves the compression lock... so much so that Im working on two designs currently that utilize the lock... if I can make them is still up in the air... Need to see if Spyderco would allow me to do so. Either way, i'll be submitting the designs to see what they think.

Posted: Fri Oct 23, 2009 11:56 am
by markg
Michael Janich wrote: I was stoked to have a compression lock on the Yojimbo. And as I am considering a potential second generation version of that design, the compression lock is a key component of it.
Put me down for three...

Seriously.

:)

Posted: Fri Oct 23, 2009 1:22 pm
by THG
Clawhammer wrote:I guess the simplest way to explain is that it's got a 'springy' piece of metal that you push to the side to 'jam' the hinge...it's kind of like an upsidedown linerlock...quite clever really...I like how even to this day people keep coming up with new stuff!!!

Anyone please feel free to jump in if I'm wrong... I've never actualy had a comp.lock knife! ;)
I think "upside-down liner lock" is a bad way of describing the compression lock. Yes, it uses a liner shaped much like a liner lock, but its function is much different.

A liner lock is a piece of a knife's liner that holds the blade up by the tang. If you put enough pressure on the spine of the blade, the lock will bend and then fail.

A compression lock is a piece of a knife's liner that gets wedged between the knife's tang and a stop pin. Pushing against the spine "compresses" the tab wedged between the stop pin and the tang of the blade. To overcome the compression lock, the tab must be crushed, or literally smashed, in order to fail. It won't bend the same way a liner lock will.