Why Do Seki Models Have Lock Rock??!!

[ladybug93]

bolster, spyderco is perfect and they just keep improving on perfection.


all i can say is thank goodness sal didn't say knives never had pocket clips or opening holes or compression locks or ball bearing locks or etc. and just leave them as they were.

[Wartstein]

...this slight up and down movement of the blade actually IS what you are all taking about...

It would be great if we could quantify this. What is "slight"?

It's difficult to tell if the disagreement between the two sides is: (1) actual different amounts of rock; or (2) the different amounts of tolerance that different owners have for relatively uniform amounts of rock across all Spyderco lock backs. (This section option is difficult for me to believe because I see large variance in rock across the many Spyderco lock backs that live in my sock drawer, but leave that aside for now.)

......

So I don't entirely disagree with those who say "it's a non-issue." I partly agree with that statement, for many/most of my lock backs, particularly the Golden lock backs. But it's an issue for some of my lock-backs.

It would be nice to be able to remove the subjective part of this discussion, and replace it with actual measurements. Maybe the insults would stop flying back and forth if we had actual measurements.

Wise words!

So what I mean and I said is:

- In all of MY Seki backlocks (quite many, most used comparably "hard") the amount of "lock rock" is so little that for me personally it is definitely a non issue indeed

- Plus: So far I have heard or read no actual, real life account that the Seki lock rock can actually be or become a "safety issue". My own experience, and also what Sal and Eric said, strongly suggest that this is just not the case.
But I am completely open to having my mind changed if someone comes up with different, real life examples!

/ I don´t see "insults flying back and forth" so far... or just a tiny bit
I personally don´t mean to insult anyone at all! I understand and respect the wish for completely lock rock free backlock folders.

[TkoK83Spy]

I honestly can't believe this is stilllllllllll going...over a little bit of wiggle??? Come on now, bet there's more important dangers lurking around your home that need attention instead of you purposely looking for lock rock on some sub $100 pocket knives.

[RustyIron]

If rock weren't a concern, if it were truly a non-issue, why would Spyderco implement the stop pin in the first place?

I don't know what considerations go into selection of a final design.

Clearly, I must not fully understand the problem. I tried to induce movement on several knives. I can detect minor movement, but nothing substantial, and nothing that I would have noticed if I wasn't looking for it. I could exert more pressure on the blade, but putting that much pressure on a folding knife seems like a good way to end up with stitches.

[Bolster]

...a little bit of wiggle....

Can we collectively define "little."

Again, the issue was "big" enough at some point for Spyderco to invent the stop pin.

[The Mastiff]

Again, the issue was "big" enough at some point for Spyderco to invent the stop pin.

That 's what they do. They always try to make better knives with new and better steel. It's what brought many of us here. I don't want a stop pin in my knife. I would like them to make them for guys that do if they can do it while leaving my favorite design alone. :)

[electro-static]

This is almost disheartening because I've badly wanted to try the K390 steel which so many people rave about. I guess I will have to wait until/if they ever produce an American model with the infamous K390 steel.

Infamous? In what way does K390 have a bad reputation?

I do think the Golden knives have better tolerances, as do the Taiwanese knives. Perhaps a lockback from one of those factories?

honestly the lock rock doesn’t impact performance if you wanna try the steel the stuff from Seki specifically is what people rave about. folks here like to nit pick things that have little to do with a knife’s actual performance as a tool.

I’d encourage you to pick up one of the discounted K390 Endura 4’s or police 4’s during the MAP holiday. I think the lil-temperance LW uses a compression lock and is made in seki. There is also the enuff 2 in K390 as well from seki if you want a fixed blade.

[JSumm]

Typically, if I am cutting through cardboard and notice a bunch of clicking it annoys me, but that is all. My Native Chief has almost undetectable rock when cutting material in air. Interesting though, if you grip a Chief too hard you will notice a lot of rock because it does not have a Boye Dent and you can accidentally loosen the lock engagement.

[Ramonade]

Typically, if I am cutting through cardboard and notice a bunch of clicking it annoys me, but that is all. My Native Chief has almost undetectable rock when cutting material in air. Interesting though, if you grip a Chief too hard you will notice a lot of rock because it does not have a Boye Dent and you can accidentally loosen the lock engagement.

On the Siren it's even more of a thing ! Me likey though.

[toomanyquestions]

If a lock back knife has not been worn-in, is there a chance a little lock rock is the result?

[Scandi Grind]

Mine had more when it first came to me than it has now, which I wasn't expecting and I'm not exactly sure how that would happen. Unfortunately I can't remember if it markedly improved before or after I took apart for cleaning the first time, but it has been totally apart twice in almost a year since I got it for Christmas. Who knows, maybe a disassembly can help in some instances, but I think there was improvement before then.

[JSumm]

What if it's on a $250 knife?

Doesn't stop me from using it. I still think this is one of the best EDC knives in existence. But I would be lying if I said I didn't care. Doesn't affect safety. Doesn't prevent me from using it, but if one of the objectives of the forum is to analyze areas of improvement I would think a topic that comes up often may be relevant. Maybe not. Maybe higher end lockbacks get a stop pin. Maybe they have the margin for that. Leave the lower end Sekis alone. Let them compete at a different level. Just food for thought. Getting to an answer is often valuable. Even if the answer is NO.

[Bolster]

Numbers!

First a Golden lock back Manix-- which I call "Apollo's Delight." Clamped on mill table. Block of wood positioned between blade and probe of the dial indicator. The point at which the block makes contact is the same distance from the pivot as the shorter Caly 3 I want to test next--that's what the arrow indicates, the tip of a Caly 3. Now pull on the wooden block (toward the viewer) with hands. First there is an "easy" pull as the blade moves back, and then a "firm" pull, and then the blade movement stops. On several trials, the easy pull reads to around .005", firm pull reads to around .010", and then no more movement. The dial probe is going away from itself, so we have to reverse the dial numbers -- "90" is in fact .010", what is shown is the end of the firm pull.

[Bolster]

Now a much admired (by me) Moki Caly 3. A superbly designed knife. Same setup, except with the shorter blade, the block presses against the tip. Several trials. Easy pull goes to .040" and then a firm stop around .045" or a bit more. Remember the dial is revolving backward for a pull, so here we are at the end of the firm pull at .045" (not .055").

Another way to think of it, if comparing the "easy" pulls to each other, is that the Caly has 8x the play of the backlock Manix.

Hopefully this will help contextualize what "a little" and what "more" lock rock is. "More" is subjective of course; I'd call it a lot, but others might not even notice it. The Manix's movement, OTOH, I don't notice (unless I'm looking for it).

[akapennypincher]

This is interesting read, and not being Knife Nurd let me say two word.

Civil litigation, when produce is unsafe, has history to hurting people.

I am sure Spyderco has people testing product before sake, product liability insurance to protect them from people who should not own butter knives.

Last I am sure Spyderco build use safe knives, with licks that work. Nuff said.

[elena86]

Well, if even the words of the guy who designed and manufactured them for decades is not to be trusted, it is sure this discussion will never result in a mutual understanding

Bwahahaha! Y'know, those are the truest words of this whole thread.

It must be hard being the renowned leader of a respected company, and reading posts about how you're doing it all wrong. My first response might be, "Why don't you go out and buy some steel and some plastic and make yourself a better knife. Until then STFU and quit bothering me." But that's why I'm not the renowned leader of a respected company.

That's not to say that some good ideas are not generated from The Forum. Even a blind pig finds an acorn once in a while. Mabye the name of the forum should be the Blind Pig Society.

Oink.

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Really !? '' ...doing it all wrong ?! ''. This was a low blow. And unjust. Nobody said anything about Sal or Sal's designs. It's the other way around. Sal's designs deserve the best implementation. The man is a genius with an awesome personality and I allways praised that. It's all about trying to improve some products(just the lock) coming from the Seki shop. You guys went too far. I stop here and now. I never imagined this...

[Skywalker]

Hopefully this will help contextualize what "a little" and what "more" lock rock is. "More" is subjective of course; I'd call it a lot, but others might not even notice it. The Manix's movement, OTOH, I don't notice (unless I'm looking for it).

Really appreciate seeing some measurements; nice work.

Now we just need to get everyone to measure their own "lock rock observation threshold" and start putting together a database of maximum deflection given a standard force (or should the torque be held constant, to account for varying distances from the pivot?) from initial locked position for various models...

Seriously, great demonstration.

[Skywalker]

Overall I agree with both Mastiff and Bolster on this one -

• The current Seki lineup are fantastic designs for users, showcasing a variety of steels and blade profiles at accessible prices. I own a bunch, give them as gifts, and will certainly buy more in the future. If this is where Spyderco's current chosen balance point is for cost of design/tooling/materials/labor/tolerances/QC, I have voted with my wallet and wholeheartedly approve.

...but at the same time...

• Most of my Seki mid back locks do have some degree of perceivable (to me) lock rock. Some are better or worse than others, some I have to really look for it, none of them do I consider unsafe - but it is there to a degree not observed on the comp/frame/liner/CBB lock Spydercos I own.
• My N5LW and CF Chaparral do exhibit much less (zero, to my in-use perception on the Chap) lock rock! Not sure if it's from improved geometry/stop pin, shorter blades, or just a lucky smaller sample (2, vs 10+ Sekis for me). I like Spyderco's back locks and would be happy to see these improvements in more models, new or updated existing.

^{-written with my worst-rocking K390 Stretch in my pocket and my no-play Sage5 CF on the desk in front of me}

[PaloArt]

I think it would be the best to implement same solution as on Chaparral - that little knife still surprises me with it`s rock solid construction and performance. There is obviously issue with this and it would be really great, if there would be some permanent solution to it via CQI. Seki knives are fantastic, I love them... but... there is this lock rock and blade vs handle ratio that sometimes make me cringe. To the naysayers - I own Delica in SS full SE and AUS-6, same handle design, just a little bit shorter handle than Gen4 and ergos are still excellent, visually extremely pleasing and without any of those issues...

Now as for the reply to the original post - I have newly acquired K390 Delica, lock rock was very pronounced but since I bought it from abroad, I didn`t want to go through all the hustle with returning. Disassembled the knife and tried to pull out, by approximately two millimeters, lock spring, closer to the pivot, away from the handle butt (if that makes sense). Now that lock rock is miniscule, still there, but not bothering that much - try it and let us know if that helped perhaps?

[Scandi Grind]

Now as for the reply to the original post - I have newly acquired K390 Delica, lock rock was very pronounced but since I bought it from abroad, I didn`t want to go through all the hustle with returning. Disassembled the knife and tried to pull out, by approximately two millimeters, lock spring, closer to the pivot, away from the handle butt (if that makes sense). Now that lock rock is miniscule, still there, but not bothering that much - try it and let us know if that helped perhaps?

Interesting, I wonder if I could have inadvertently done as you described when I disassembled my Endura. I am very curious now to know what component or components actually contribute to the amount of lock rock at this point. It seems from what I could tell, most if not all of the movement in mine was at the pivot, but it is difficult to tell if anything else could be moving.

It seems like it would be pretty cool to get a stop pin in Seki models, it always sounded like an efficient and effective solution, but I assume that would require a new version of all the modified knives, and would require new tooling etc, etc, which all adds up to costs costumers would have to pay for, and I'm not sure that it would actually boost sales. That all makes it a potentially difficult sell, especially when so many people seem quite satisfied with it in it's current state.

That said it seems like to me there is not much that can be improved mechanically at this point (ergos are a different story), except for maybe adding a stop pin. So logically from a CQI perspective, this seems like the way to go. If it solved what instances of lock rock we see now, it would be very difficult to fault the knife mechanically and it will have achieved about as close to perfection as I imagine you can get in it's given price bracket, even if the price did rise a little.