Why Do Seki Models Have Lock Rock??!!

[Flash]

[/quote]

I don't think comparing the lock-up of different locks is useful in this situation.
[/quote]

Ive been comparing budgets, not locking mechanisms.

My point is (and has been) Seki models shouldn’t have these on-going issues at their price point.

[Ramonade]

I've been searching for sal's post about this very topic since last night.
I remember him saying something like it's in the nature of the lock design, that even if lock rock is imperceptible at first, the 2 surfaces of the lock interface hitting each other repeatedly will wear them over time and create a slight movement.

But since it's only what I remember, I'm going to find that post. It's in a thread similar to this one, message posted a year or two ago tops.

ETA : similar thread viewtopic.php?f=2&t=94599

ETA 2 : A quote from Chad Kelly / CKC / Xplorer :

No surprise that they would want to inspect it for themselves. Even though you probably have the right solution in mind, the probability that someone misdiagnoses the cause of lock rock on a back-lock is very high.

I would suggest you either send it in or just live with it and try not to let it bother you. It shouldn't cause any actual functional issues.

All back locks will have a very slight amount of lock rock even when new. Everything may be so tight at first that it's nearly imperceptible but it's there if you push hard enough and look closely enough. The lock bar and the blade have to be able to move freely on their respective pivots. In order to allow this the hole for each pivot must be at least .0002" - .0005" larger than the pivot barrel. Most companies cannot hold tolerances to less than .001" and I believe I've read Spyderco is able to hold tolerances to within .0005" in some cases, but I'm not aware of ANY production knife company that can actually hold .0002". When the lock bar locks into the blade it effectively connects the blade pivot to the lock bar pivot and when you put pressure on the blade you can see it move. The movement will be the amount of "play" in the two pivots. Since the blade pivot acts as a fulcrum in this case, the movement measured at the tip of the blade is more amplified the longer the blade is. As a knife wears with use the tolerances grow and the movement becomes more noticeable.

So, while the blade pivot barrel is likely to be a significant wear area you also have to assess the lock bar pivot wear, the blade pivot hole itself, and the lock bar pivot hole as areas that may be contributing to your concern. If I'm remembering correctly, the Caly has a riveted (or pinned) pivot that is not easily removable/replaceable. It is specifically because there are 5 wear areas (lock/blade interface included) that need to be examined carefully, and 2 of them are not easily removable (lock bar and it's pivot are riveted or pinned if I'm remembering correctly) that i would suggest you send it in...or just try to ignore it.

CK

About that, there's a reason why the Native 5 is and should be celebrated as one of the best examples of a mid-backlock in the world !

ETA 3 : from this thread : viewtopic.php?f=2&t=91897

We've been making mid lock-backs since 1981. It was a lock design that had a long history ( Harvey McBurnette, Al Mar, etc.). For a variety of reasons they are actually quite difficult to make. Our Seki Makers have continually improved them over the past 40+ years.

sal
_________________________

We've been making The Endura in Seki since 1990 with the same maker. We have literally millions of them in the field. They have a very good reputation and we've been refining them for over 30 years. They are currently in their 4th iteration.

sal
_________________________


I don't think a picture of your old Endura would be relevant to what we're making now. we've made many changes to our Endura model over the years. However, if you prefer Cold Steel's lock-backs, that OK. Lynn Thompson always made good quality knives. Lynn and I go back a long way. I don't understand the point of your conversation?

We continue to improve our locks (all types) and our designs regularly. We make new tooling, make improved molds, change materials and add many new models. We make test models of different steels for our customers to do their own research. This is something I don't see other knife companies doing like we do. We have our own factory in the USA and we work with high quality makers in; Japan, Italy, Taiwan and China. The same ones for decades. We have our own testing lab and we're constantly testing.

Our CQI ( Constant Quality Improvement), new designs, and engaging, like I am doing with you right now, is something our customers enjoy and appreciate. Our knives are carried by Military, Law Enforcement, Fire Fighters, First Responders and any group that needs and depends on reliable High Performance.

Each knife company has it's own niche and it's own market. If you are in Cold Steels camp or market, perhaps you will be happier sticking with them? In my opinion, the Triad lock, like any lock also has issues.

But thanx for offering your opinion, which we always appreciate.

sal

[Flash]

I have side-to-side blade play on my Delica.

I took it apart and made a few measurements. The pivot screw is 4mm but the pivot hole in the tang is 4.17mm in diameter - far too big a hole in my opinion for such an application.

I would have thought a 4.05 with a tolerance of +/- 0.02mm hole would have been optimal here.
To hazard a guess maybe worn tooling was used at the Seki factory and with K390 being not the easiest to machine, combined with a too lenient QC has unfortunately landed me a knife I’m not particularly happy with.

[ladybug93]

.....

.....

i feel like we've had this discussion before. i don't really want to rehash it again. i will say though, from reading your post, we agree on pretty much everything except the conclusion, which you seem tied to by bias. subjectively, a manix lw (no liners) has a more sturdy and confidence inspiring feel than an endura with liners. objectively, it's less likely to have blade play in use and it flexes less under pressure/torque. and a g10 manix and an endura with liners are not even in the same category of knife, in my opinion.

since you mentioned hollow grind vs flat, i'll say that's another point we agree on. the problem is that the hollow grind of the pacific salt is attached to a weaker pivot and handle, and a lock interface that allows movement.

you know the manix and the pacific salt are my favorite knives and almost exclusively the combo that i carry daily. there is plenty good reason for that. i am not crapping on either of them. i have used both of them harder than they were probably designed to be used and they are both still favored. that doesn't mean they are perfect.


really, we could settle this very easily. if you could choose between two knives that were exactly the same, but one had rock solid lockup and the other had the standard seki lockup, which would you choose? my guess is that you would go for the more solid feeling option.

Not sure where my "bias" should be, nor if my reply to your post came out wrong perhaps?

I was just literally asking you out of interest what in your experience a Manix could take that a (sabre grind, but also ffg) Endura can´t, cause you said (quote): "since i'm survival minded, i settle in the middle with the manix. it's beefy enough to be pushed harder" - I just think both a Manix and an Endura will handle any just remotely sensible folder task, but I´d definitely beat on a sabre grind (!) Endura blade even harder than on the ffg Manix blade. The handles and pivots will take it anyway on both models.

To me, also subjectively, a linereld Endura definitely feels sturdier than a Manix LW (though the latter is plenty sturdy, no doubt).

"Movement of the lock" the way Seki backlocks show in my opinion is not relevant at all when it comes to hard use / sturdiness / what a folder can take (again, just a weird and probably wrong theory: The little bit of give might even ADD "strength" to the lock, like a damping can do).

Nothing to "settle" here, I think. As you said: We agree on most things anyway, just have slightly different conclusions / opinions / experiences. If those are "biases", this is true for you just as much as for me .

/ And yes, you are right: like already stated in my last post: All other things completely equal I´d take no lock rock over lock rock indeed.
It just really does not bother me or matter to me. Never caused any issue or even weird feel when cutting in my long experience with Seki backlocks.
But if Spyderco can make their Seki backlocks (more) "lock rock free" without having to raise the costs for the knives: They probably should.

the bias i'm referring to is the first thing you said to me in this thread. you said that seki lockbacks are your favorite lock for personal reasons. i wasn't trying to accuse you of anything. i was just restating a fact you had shared. it's perfectly fine to have the bias as long as you recognize it and don't negate objective fact because of it.

it seems we are thinking about sturdiness differently. from what you are saying, sturdiness is almost completely in the blade shape and grind rather than how the knife works together as a whole. you mentioned dampening, but i can't imagine why you would think a dampening effect would be favorable in a knife as a measure for sturdiness when it means there is a small amount of give in your cut. for me, the sturdiness i'm referring to is how solid the tool feels in use and whether there is flexing of the handle or movement at the pivot while in use. you must have super endura if you think they do this less than a manix lw, or again, we're just defining sturdy differently.

i mentioned in my original post that the seki backlocks can definitely be pushed into harder use. i have no doubt that they are capable of doing work. the problem is that, while i trust them to handle a situation, i wouldn't necessarily want to depend on them to handle a prolonged scenario. it's obviously not something that keeps me from carrying them. i've been pairing my wharncliffe delica with my pacific salt lately almost as much as i have been a manix.

thinking through this as i type, i realize that, in a survival situation, i'm going to make whatever i have work. i'm going to use whatever tool i have to the capacity i can without endangering myself or the longevity of the tool, and i likely wouldn't treat even a swiss army knife much differently than an endura or a manix. at the end of the day, they're still folding knives, but i'd still rather have a manix than an endura and i'd rather have a 4max than a manix and i'd rather have a fixed blade than a folder if i were in a survival scenario.

[vivi]

I don't think comparing the lock-up of different locks is useful in this situation.
[/quote]

Ive been comparing budgets, not locking mechanisms.

My point is (and has been) Seki models shouldn’t have these on-going issues at their price point.
[/quote]

why not?

[Flash]

I don't think comparing the lock-up of different locks is useful in this situation.

Ive been comparing budgets, not locking mechanisms.

My point is (and has been) Seki models shouldn’t have these on-going issues at their price point.
[/quote]

why not?
[/quote]

Why so?

[apollo]

I guess i am really really lucky then. I can do what i want with any of my lock backs and none have even the slightest degree of lock rock.
But i do need to say i will never have to fear any job with my old lock back Manixes. I see myself failing physically before those locks do.
Everything Vivi does with his knives i also do. Not that i need to do these tasks for camping or something but i just do them for fun.
Dont know what is wrong with me but doing that stuff releases stress in my case.
But that said i would never use a Lw knife for that stuff not because they can not do it. But Just because i find them not comfortable enough. I really prefer a good slab of handle then a thin skinny thing any day of the week.
I do want to clear one thing up of my last post.
I still see seki spydies as great quality knives. They just don’t give me the same bang for your buck feeling Golden or taichung spydies do and i just wish they slightly improved on that matter.
I think that is because they’re prices went up but they’re quality stayed the same. While i can clearly notice improvements in golden spydies. For example my older Manix 2’s fit and finish are not as good as my new ones. Same go’s for the Native’s. But i if a handle a Delica in a store it still feels the same as the one i had for years but now its just double the price.

As discussed above: I think it could be a matter of what people understand by "lock rock":
When I first heard the time some time ago, I thought it was about serious movement of the blade.
But now I guess most times it is "just" that mostly very subtle upwards movement of the blade when really pressing it hard on matter. This, I guess, most Spyderco backlocks have if one really concentrates on perceiving it.
Might be different though in YOUR examples of course, and normally is not an issue anyway imo.

/ I get you point of wanting a more "comfortable" handle for harder tasks! This, I guess, is subjective again though:
I find for example the chamfered , linered, very solid and pretty wide Stretch (1 or 2) handle more comfortable in hard use than lets say a PM2s and I am sure also a G10 Manixs (to be clear: Only handled a G10 Manix, never really used one!)
And for real "hard use" where one has to squeeze the handle tight over longer periods of time: I´d take an Endura any day of the week comfortwise over my Manix 2 LW - which, in shape, is pretty much the same as a G10 Manix, perhaps even a bit more comfortable (slight chamfering, completely closed back)

/ I also feel the quality of the Seki Spydies has gone up: A bit tighter tolerances in the newer ones, and, as far as I can tell, their "main steel" VG10 has better edge retention now (nothing scientific though!)
Loose screws though are an issue that seems to occur with Sekis

Anyway: Pretty much all subjevtive, and all good my friend!

I guess you are right and it’s all subjective in the end to the person testing it all.
Per haps if you are vivi would test my lock backs you guys could notice something that i just can’t feel.
Not that it matters even with the lock rock mentioned lock backs they would still be the king of locks safety wise in my eyes. Spyderco’s lock backs are so trustworthy i would be shocked to see one fail without doing something completely utterly stupid to it.

About comfort i guess it already starts depending on your hands them selves. What for one hand is comfortable can be to big or small for the other I presume.
I did have an endura 3 once and well i liked it overall very well. Then i sold it to get my used Chinook 2 and got hooked on tanky knives and never looked back.
About the quality of seki’s like i said before i think they are all still great knives. So i believe you when you say you notice improvements since you actually own and use them.

Funny thing you say that about vg-10 tough. Because i feel the opposite about s30v.
It can be just a ghost in my head but i can swear my old C95 and Mini Manix there S30V has a little better edge retention then my newer Manix 2’s. Not extremely offcourse but very very slightly i just notice i need to sharpen them less then my s30v Manix 2’s.

Ps. I always like seeing you react to my posts. You are one of the nicest people on this forum and i like discussing spyder talk with you!

[Bolster]

Previously I’d said I’d sent all my big rockers downriver. I’d forgotten about the Caly 3 rocker in my glove box. I adore this knife’s design. I think it’s my favorite Spyderco design…minus the lock rock, and minus the VG-10, that is.

The rock is discernable by simply pressing your index finger up into the finger choil. It makes a clicking sound when you do this. Under the thumb you can feel the lock bar moving. If you grasp the blade behind the spine and pull, the rock is readily discernable. If you are cutting against a firm surface, there is a sort of “squish” factor as the blade contacts the work, until all the tolerances are taken up, and then it’s firm. (I do not notice it when cutting something soft like an apple.) I have not clamped the knife in a vise for a precise measure, but holding the knife in my left hand as firmly as I can, and pulling on the blade with the right hand, over a ruler, it looks like the tip of the blade moves 2 mm up and down.

Now… is that “bad” lock rock? It is to me but it may not be to you. Do I think it’s unsafe? Not a bit. Do I like the movement of the blade? Not a bit. That’s why this one got relegated to glove box duty.

See, it’s a matter of degree. If the speed limit is 55, will a cop give you a ticket for going 60? That has happened to me twice. But the stretch of highway nearest where I live, everybody drives 80 and nobody gets stopped.

Is there rock in my other lockbacks? Probably, but I don’t notice it. It’s a matter of degree. For me, some of my Sekis have had enough rock that they “get a ticket” and they get sold off to people who don’t mind the rock. I’ve not ticketed any Golden lockbacks yet; in my experience they lock up much more solidly.

A stop pin could put a stop — not only to the lock rock, but also to the complaints.

[Scandi Grind]

It seems like it is almost impossible to sort through what everyone is seeing with their respective knives because we don't have a way to compare them to each other. It would be kind of cool if we could get a bunch of knives that have been deemed to have excessive lock rock in one spot and compare them to some that are considered more average.

Or maybe something as simple as laying the knife edge down on a cutting board, then measuring the difference in height of a specific marked location on the handle when no pressure is applied and then pressure is applied could give us at least some comparable data, even if it is somewhat rudimentary and not super precise.

[Bolster]

... we don't have a way to compare them to each other. ....

You didn't like my 2mm tip deflection measurement above?

[Scandi Grind]

No, your measurement is great for some point of reference! It is just that most of the posts so far haven't had any measurements to go off of, so it has been hard to really know what we are talking about from one instance to another. It would be nice to get more measurements from others.

I went ahead and tried my best to get some sort of measurement from my Endura, but it is so little it is hard to measure effectively. It looks like if I put pressure on my knife lying with the handle and edge on a cutting board, the finger guard can move only about .5 mm toward the cutting board. Not a very accurate measurement but it definitely isn't a full mm of movement. Another thing that I noted was that most of that movement seems to be in the pivot from what I can tell.

This particular knife feels very good to me in use and that measurement seems to confirm that this one is pretty tight. It had more movement originally, but obviously I can't measure how it used to be now.

[The Mastiff]

A stop pin could put a stop — not only to the lock rock, but also to the complaints.

A stop pin would make it a different lock therefore a different knife at a different price. I don't want that knife. I want them exactly as they are now. No newer or more expensive models for me. I have carried these since 92 and want them to continue building them the same but with new steels to try now and then.

Not everybody agrees with those wanting change nor would I agree with fixing problems that to me don't exist.

[JSumm]

If you don't like excessive lock rock, you can ask the dealer to check for it when purchasing and ask them to pick the least amount of the bunch. That has worked well for me for my last few Seki model purchases.

[James Y]

If you don't like excessive lock rock, you can ask the dealer to check for it when purchasing and ask them to pick the least amount of the bunch. That has worked well for me for my last few Seki model purchases.

^^This.^^

Whenever I ordered knives, I called the dealer over the phone, instead of just clicking and hoping. I had a short list of things to check the knife for, and least amount of lock rock was part of that list. Out of all those orders (the large majority of which were Spydercos, and most of those were Seki-made), I got maybe two that had some perceptible lock rock out of the box, and they weren't that bad. Not enough to be a safety issue. I've mentioned my method of ordering with a live person over the phone a few times over the years, but most people ignore it and would rather 'click and hope'.

I used to get more lock rock in lightweight Seki back locks, back in the late '90s/early 2K. I was under the impression that the tolerances in their back locks had actually improved in more recent years. But maybe that was because of the way I was ordering my knives.

Jim

[Studiousworkman]

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?

K390 does not have a bad reputation. Infamous meaning "widely known and accepted". I can use a different word or phrase to describe the steel though - K390: "Highly regarded, excellent, top notch, fantastic, one of a kind." Hopefully Spyderco will release another American model in the future with this steel because I refuse to pay these inflated eBay prices which some collectors have the audacity to charge when a model is a limited run.

[Bolster]

A stop pin could put a stop — not only to the lock rock, but also to the complaints.

A stop pin would make it a different lock therefore a different knife at a different price. I don't want that knife. I want them exactly as they are now. No newer or more expensive models for me. I have carried these since 92 and want them to continue building them the same but with new steels to try now and then.

I'm not sure about a large price increase if a stop pin is added; it's difficult to determine by examining current offerings.

If you search just current Spyderco XHP knives, the Chaparral, which has a stop pin, is the cheapest XHP offering by far, coming in at $167 MSRP. But steel isn't the only predictor of price, obviously.

I didn't know until reading this thread that the Sage 4 had a stop pin. But it also has Titanium bolsters and Az Ironwood scales. Its MSRP was $310, the same as the Sage 2, with plain Ti scales and a framelock.

I don't know if adding a stop pin would add a significant amount to the price or not; however the FRN Chap doesn't seem out of range, price-wise.

Regards the back lock with a stop pin being a different lock, I think that's a semantic argument.

[Bolster]

Infamous meaning "widely known and accepted".

No.

[Studiousworkman]

With the amount of money we are required to pay for owning your typical Spyderco, there really shouldn’t be any kind of perceivable lock rock, blade play or any other kind of blade movement upon deployment and use. No movement is acceptable at these price points.

I should not be receiving a lock knife which deploys a blade that isn’t fully locked into position. If there is movement it tells me the knife / it’s components have not been subjected to the correct quality control protocols or that there’s a fault in the design.

Fortunately Spyderco is generally one that doesn’t rest on its laurels too much, and when a problem is highlighted it is dealt with by its CQI policies. However, these policies don’t appear to be administered across the entire range of factories - Seki City being one of them - highlighted in my experience by “on going” blade play and lock rock problems with the Delica.

I know it’s a simplistic way of looking at things but it still stands; if a £10 Opinel doesn’t have blade movement when the lock is applied, then a £100 Spyderco also shouldn’t.

Wise words !

I second this!

[Studiousworkman]

Infamous meaning "widely known and accepted".

No.

My apologies. It does mean generally regarded as bad, unacceptable, notorious. I used it in the term of being widely known. It's famous K390 since that is the word you're looking for.

This post was supposed to receive good feedback, which some definitely have, not turn into a firestorm of keyboard warriors defending their opinions and loving to start arguments because they haven't grown up.

I do appreciate all who've commented with their constructive criticism and honest feedback and experience.

The bottom line is, as some have stated outside of myself, there shouldn't be any blade play in these knives which is not only concerning but dangerous in the long run. I exhort anyone who hasn't already, to dip their toe into the world of custom knives. Go out and spend a lot on a custom piece (do your research on makers though). You won't be disappointed. Please see the tight tolerances, flawless grinds, and attention to detail of these amazing products and I'd like to see blade play or lock rock of any kind be acceptable or "not concerning" in that kind of market. That clientele wouldn't have it. [Example: Ford or McLaren; Kia or Koenigsegg]

The production market such as Spyderco, Benchmade, Hogue, Microtech, Pro-Tech, etc. probably makes up the biggest profit margin in the knife industry. However, if custom knife makers had thousands of forums to expose their repetitive flaws (the kind that production companies all carry over) the industry would take a huge loss in income from these makers. Just one custom knife most times can be the same price as 10-20 production knives. For all those who say custom isn't worth it, you have not idea, because, you don't know what you don't know.

Custom makers have a reputation to maintain and they won't let things like lock rock, blade play, bad grinds, poor heat treatment and many other things ruin their products or sully their name. That's why there are so many stellar custom makers making and selling some of the highest quality knives on the market. We live in a golden age of knifemaking and it's exciting to see what will happen even in the next 10-20 years!

[Sharp Guy]

All lockbacks will have some movement. It's part of the design. I have Seki lockbacks using the same geometry and design now over 30 years old and still going strong. The knives haven't changed IMO going by my latest Endura in M4.

They are what they are. Buy them or not. I keep on buying new ones and I have been happy with them. Other people apparently not so.

I have yet to see any chopped off fingers from Seki locks so if anyone here has proof please give us a link to some evidence.

Yep! Wise words here too!

Have any of you posting in this thread had a lock failure with one of these knives? A hint of lock rock doesn't mean the knife is dangerous or the lock is going to fail. Can someone tell me how a tiny bit of lock rock is going to make the lock fail?

As The Mastiff said, the Seki lock backs have been like this since the start. Here we all are still buying them. Why? Because there's no actual issue with them.

A few years ago Spyderco spent a lot of time (and I assume money) to make the Native 5 lock as good as they could. I tested Native 5 LWs last night. Tonight I tested some G10 models and one with fluted Ti scales and one with fluted cf scales, all with steel back spacers. Guess what? If I push hard enough even these have a tiny bit of lock rock. About the same as the Seki models I tested. Native 5s are made in Golden. Yet they still have a tiny bit of lock rock. Because it's just nature of the beast.

So put away your torches and pitchforks and either buy them or not. I can't speak for Spyderco but I bet these knives are the same next month. Someone will bring lock rock up again and we'll go through this same exercise all over again