Spyderco Forums

Seki FRN lockbacks (Endura, delica, endela, stretch 2lw, ect..) are my favorite spyderco models, the combo of comfortable handles and great cutting geometry really works well for me. However most of mine have lock rock when really bearing down on a material that I am cutting. Anyone know how to fix this?

This is a complaint I've never understood. Not saying it isn't legitimate, only that I don't understand. I can duplicate the phenomenon if I try, but I have never experienced it to a perceptible degree while actually cutting something. So I have to ask, and please, I'm not trying to single you out:
1) what are you cutting that requires so much force?
2) should you perhaps try a different cutting technique, e.g., slicing vs. push cutting?
3) is your knife as sharp as it needs to be? Using excessive force because your knife isn't sharp is hazardous.

I don’t know if it is fixable. Lock rock when bearing down during cutting is common in many back locks, not only Seki models. I’ve had Buck knives (110, Mini-Buck, and others) that had similar lock rock as some Seki models. I never bought one of the original Golden Native models because every one I handled at a store had lock rock, and not even by cutting anything. I’ve also had Seki models that had no lock rock. IIRC, I think Sal mentioned years ago that a certain degree of lock rock is to be expected in back locks.

IMO, the CQI’d back locks on the my G10 Native 5 and Native Chief are an improvement over the older back lock design. I still love my Seki back locks, too.

Jim

dsvirsky wrote: ↑

Sun Mar 26, 2023 12:11 pm

This is a complaint I've never understood. Not saying it isn't legitimate, only that I don't understand. I can duplicate the phenomenon if I try, but I have never experienced it to a perceptible degree while actually cutting something.....

Same here.

I do respect if someone has issues with (Seki) lockrock, and, yes, I can provoke it myself deliberately when really pressing a (Seki) backlock down on a surface, but it never, ever bothered me in the slightest with any of my Seki backlocks (and I had/have a lot of those). Does not do anything bad to cutting performance too imo.

dsvirsky wrote: ↑

Sun Mar 26, 2023 12:11 pm

This is a complaint I've never understood. Not saying it isn't legitimate, only that I don't understand. I can duplicate the phenomenon if I try, but I have never experienced it to a perceptible degree while actually cutting something. So I have to ask, and please, I'm not trying to single you out:
1) what are you cutting that requires so much force?
2) should you perhaps try a different cutting technique, e.g., slicing vs. push cutting?
3) is your knife as sharp as it needs to be? Using excessive force because your knife isn't sharp is hazardous.

It seems to me that most of the time it needs to be pretty bad to feel it during use. I had a Stretch that had it so bad, every time you pressed into a cut you could feel a pop in the pivot where the lock bar would shift into the tang. That one was deemed defective.

I can't fault people for not liking it. What I'd just like to see is a conversation between the folks in Golden and the folks in Seki because whatever they're doing with back locks in Golden is outstanding. What's really weird is my stainless handled Police has such a perfect lockup and it's made in Seki too, I wonder if the issue comes from the liner/FRN construction because the Golden linerless lightweights seem to have better consistency with lockup than the linered Seki models and that's weird to me because I'd think liners would tighten everything up. It's really amazing that Golden are making molds that are so accurate that they don't have pivot/lock play.

Evil D wrote: ↑

Sun Mar 26, 2023 1:24 pm

dsvirsky wrote: ↑

Sun Mar 26, 2023 12:11 pm

This is a complaint I've never understood. Not saying it isn't legitimate, only that I don't understand. I can duplicate the phenomenon if I try, but I have never experienced it to a perceptible degree while actually cutting something. So I have to ask, and please, I'm not trying to single you out:
1) what are you cutting that requires so much force?
2) should you perhaps try a different cutting technique, e.g., slicing vs. push cutting?
3) is your knife as sharp as it needs to be? Using excessive force because your knife isn't sharp is hazardous.

It seems to me that most of the time it needs to be pretty bad to feel it during use. I had a Stretch that had it so bad, every time you pressed into a cut you could feel a pop in the pivot where the lock bar would shift into the tang. That one was deemed defective.

I can't fault people for not liking it. What I'd just like to see is a conversation between the folks in Golden and the folks in Seki because whatever they're doing with back locks in Golden is outstanding. What's really weird is my stainless handled Police has such a perfect lockup and it's made in Seki too, I wonder if the issue comes from the liner/FRN construction because the Golden linerless lightweights seem to have better consistency with lockup than the linered Seki models and that's weird to me because I'd think liners would tighten everything up. It's really amazing that Golden are making molds that are so accurate that they don't have pivot/lock play.

It's not only linered Seki models. My very first Spyderco knife back in 1997 was a linerless Delica that had lock rock when you pressed into a cut. Back then, none of Spyderco's FRN back locks had liners. I don't think it has anything to do with liners. I think it has to do with the way the lockbar fits into the tang notch. Like I posted above, I've had lock rock in a Buck 110 during cutting pressure.

I own 4 SS Police models, and only one of them has lock rock. Not every sample of any particular model will be have the same tolerances.

I too would like to see the CQI'd Golden back lock design incorporated into the Seki models.

Jim

James Y wrote: ↑

Sun Mar 26, 2023 1:35 pm

Evil D wrote: ↑

Sun Mar 26, 2023 1:24 pm

dsvirsky wrote: ↑

Sun Mar 26, 2023 12:11 pm

This is a complaint I've never understood. Not saying it isn't legitimate, only that I don't understand. I can duplicate the phenomenon if I try, but I have never experienced it to a perceptible degree while actually cutting something. So I have to ask, and please, I'm not trying to single you out:
1) what are you cutting that requires so much force?
2) should you perhaps try a different cutting technique, e.g., slicing vs. push cutting?
3) is your knife as sharp as it needs to be? Using excessive force because your knife isn't sharp is hazardous.

It seems to me that most of the time it needs to be pretty bad to feel it during use. I had a Stretch that had it so bad, every time you pressed into a cut you could feel a pop in the pivot where the lock bar would shift into the tang. That one was deemed defective.

I can't fault people for not liking it. What I'd just like to see is a conversation between the folks in Golden and the folks in Seki because whatever they're doing with back locks in Golden is outstanding. What's really weird is my stainless handled Police has such a perfect lockup and it's made in Seki too, I wonder if the issue comes from the liner/FRN construction because the Golden linerless lightweights seem to have better consistency with lockup than the linered Seki models and that's weird to me because I'd think liners would tighten everything up. It's really amazing that Golden are making molds that are so accurate that they don't have pivot/lock play.

It's not only linered Seki models. My very first Spyderco knife back in 1997 was a linerless Delica that had lock rock when you pressed into a cut. Back then, none of Spyderco's FRN back locks had liners. I don't think it has anything to do with liners. I think it has to do with the way the lockbar fits into the tang notch. Like I posted above, I've had lock rock in a Buck 110 during cutting pressure.

I own 4 SS Police models, and only one of them has lock rock. Not every sample of any particular model will be have the same tolerances.

I too would like to see the CQI'd Golden back lock design incorporated into the Seki models.

Jim

I just meant it seems more common with the linered knives, and to say that it's interesting that I've had I think five Native 5's and they were all rock solid. I know 5 is a very small sample size though.

Evil D wrote: ↑

Sun Mar 26, 2023 1:24 pm

dsvirsky wrote: ↑

Sun Mar 26, 2023 12:11 pm

...

It seems to me that most of the time it needs to be pretty bad to feel it during use. I had a Stretch that had it so bad, every time you pressed into a cut you could feel a pop in the pivot where the lock bar would shift into the tang. That one was deemed defective.

I can't fault people for not liking it. What I'd just like to see is a conversation between the folks in Golden and the folks in Seki because whatever they're doing with back locks in Golden is outstanding. What's really weird is my stainless handled Police has such a perfect lockup and it's made in Seki too, I wonder if the issue comes from the liner/FRN construction because the Golden linerless lightweights seem to have better consistency with lockup than the linered Seki models and that's weird to me because I'd think liners would tighten everything up. It's really amazing that Golden are making molds that are so accurate that they don't have pivot/lock play.

Ok, that´s bad (your Stretch) and WOULD bother me too indeed.

The slight lock rock most of my Seki backlocks have honestly does not at all.

But that said: Of course the Golden backlocks (had it in a Native) feel amazing and if I could choose, I´d take them over a Seki backlock, all else being equal. The Chap (Taichung) backlock with its stop pin is great anyway.

dsvirsky wrote: ↑

Sun Mar 26, 2023 12:11 pm

This is a complaint I've never understood. Not saying it isn't legitimate, only that I don't understand. I can duplicate the phenomenon if I try, but I have never experienced it to a perceptible degree while actually cutting something. So I have to ask, and please, I'm not trying to single you out:
1) what are you cutting that requires so much force?
2) should you perhaps try a different cutting technique, e.g., slicing vs. push cutting?
3) is your knife as sharp as it needs to be? Using excessive force because your knife isn't sharp is hazardous.

My Ayoob does the lock rock when I cut through cardboard while pinching the scales (rather than thumb against the ramp). It doesn't happen when force is being directed into the thumb ramp. I also noticed some slight lock rock on a ladybug that occurs even on a light cut.

I can live with it but it is pretty annoying to have the blade suddenly pop during a cut.

I took this picture a while ago of how far the lock bar on the ayoob would go if I did a hard cut.

Is it lock rock or lock pop up?

Lock rock, to me, is when you can wiggle the blade up and down with not all that much force.

Lock pop up is when you can get the lock bar to come up when pressing down on the knife.

Almost all mid back locks will exhibit lock pop up if you apply enough pressure.

I have exactly one Seki City knife, a Dragonfly 2, that has a very small amount of lock rock.

OP: I investigated lock rock a couple years ago, asked around lots, and discovered it's not realistically fixable due to the complexities of the lock-work and how the parts relate to each other. Only fix is to replace the knife.

I now watch for lock rock on new knives (any brand, it's not brand exclusive) and send them back if they rock. Life's too short to deal with lock rock, IMO.

Lock rock is not your problem, or a perception problem, or a usage problem; it's the knife's problem. If the lock rocks, it rocks. If it bothers you, it bothers you. End of story. Up to you to decide whether you'll put up with it or not. As time marches on, and technology improves, I have less tolerance for it personally.

I've found the most solid lock-ups with CBBL and Comp Lock and have gravitated toward them recently. I really enjoy a solid feeling knife -- wiggly blades are annoying.

Bolster wrote: ↑

Sun Mar 26, 2023 6:44 pm

OP: I investigated lock rock a couple years ago, asked around lots, and discovered it's not realistically fixable due to the complexities of the lock-work and how the parts relate to each other. Only fix is to replace the knife.

I now watch for lock rock on new knives (any brand, it's not brand exclusive) and send them back if they rock. Life's too short to deal with lock rock, IMO.

Lock rock is not your problem, or a perception problem, or a usage problem; it's the knife's problem. If the lock rocks, it rocks. If it bothers you, it bothers you. End of story. Up to you to decide whether you'll put up with it or not. As time marches on, and technology improves, I have less tolerance for it personally.

I've found the most solid lock-ups with CBBL and Comp Lock and have gravitated toward them recently. I really enjoy a solid feeling knife -- wiggly blades are annoying.

Thanks for the response, it was exactly what I was looking for.

Golden’s N5 lockup is solid, so it madd me curious if the same could be done with mods for a seki model.

It isn’t a problem functionally for any of them it’s not like the lock is in danger of being disengaged, and is only really noticeable if I bear down on something like wood.

It’s more of a “man this would be just about perfect if not only for this one minor thing” type of thing for me. (I like them well enough that I am sending my beater that was sharpened until it was like 1mm behind the edge to be re-ground)

I was thinking more along the lines of if there is a pin I could replace or a lock face I could polish, I work in manufacturing so I can refinish stuff and buy new pins.

I do think generally Seki gets too much heat, of the spydercos I own in my experience they are consistently the most comfortable to hold, and the thinnest ground behind the edge (not to mention are produced in amazingly heat treated K390). If it can’t be helped it can’t be helped it’s just a bummer because they are close to perfection for me.

There is going to be lock rock to a small degree in back locks, especially mid back locks. The only back locks that I know of that have no lock rock are the Spyderco Chaparral and the Triad Lock, both of which have use a stop pin.

I'll start by saying that lock rock has never really bothered me. On all the Seki models I have (all FRN) it exists to some degree but I never notice it in normal use. I can grab the blade and push the handle down to make it happen. However, I picked up an Uptern recently and found that it has zero lock rock. So what is it about FRN, or Seki, that causes/allows lock rock?

Doc Dan wrote: ↑

Sun Mar 26, 2023 11:27 pm

There is going to be lock rock to a small degree in back locks, especially mid back locks. The only back locks that I know of that have no lock rock are the Spyderco Chaparral and the Triad Lock, both of which have use a stop pin.

Not sure if it will always be there in a small amount because i never seen lock rock in any of my old Manixes or chinooks. Also have not seen it any of my natives yet.
Maybe its just an issue that happens in like 1 to 5 % of the pieces of a batch of knives?
If i am honest and i think about it harder i can not say i ever had a spydie with lock rock before. I do have one very lousy made buck lockback from when i first started collecting 20 years ago. Its so badly made i keep it as a memento on how much my taste in knives has improved

apollo wrote: ↑

Mon Mar 27, 2023 1:14 am

Doc Dan wrote: ↑

Sun Mar 26, 2023 11:27 pm

There is going to be lock rock to a small degree in back locks, especially mid back locks. The only back locks that I know of that have no lock rock are the Spyderco Chaparral and the Triad Lock, both of which have use a stop pin.

Not sure if it will always be there in a small amount because i never seen lock rock in any of my old Manixes or chinooks. Also have not seen it any of my natives yet.
Maybe its just an issue that happens in like 1 to 5 % of the pieces of a batch of knives?
If i am honest and i think about it harder i can not say i ever had a spydie with lock rock before. I do have one very lousy made buck lockback from when i first started collecting 20 years ago. Its so badly made i keep it as a memento on how much my taste in knives has improved

The absolute worst lock rock I've ever had in any folder was on a USA-made Buck Mini-Buck.

Jim

I keep repeating : why don’t they implement the internal stop pin ???!!! It’s not brain surgery ! Oh and yeah, that lock rock is annoying, to say at least and it’s unacceptable when you pay 100+ for a knife… at least for me. Those guys from Seki should step up their game, we are in the 21 century after all.

The lock rock on the Delica is why I stopped carrying it. I do a fair bit of cutting down on a surface, and that slight movement/tick bothered me, though it never felt like a safety concern. Interestingly, I happily carry the Delica wharncliffe but that's because I don't use it in a way that provokes the issue.

It's a shame because I am a fan of the Seki FRN, but I've come to avoid Seki lock-backs.

If there is a Delica 5, I hope Spyderco will add an internal stop pin à la the Chaparral. In the meantime, I have other knives in that size class.

It would nice to see the mechanism updated/upgraded. I can live with it though.

elena86 wrote: ↑

Mon Mar 27, 2023 5:03 am

I keep repeating : why don’t they implement the internal stop pin ???!!!

Reading this thread, I wonder as well. If it could be successfully applied to other, comparable Spyderco knives, why wasn't the stop pin generalised to all backlocks ? (Except perhaps the minuscule keychain ones, as their use case might not warrant it).