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lockstick - my thoughts and your facts or theories

Posted: Fri Feb 28, 2020 3:01 pm
by archangel
I own a few spydies that have it. The K2's is probably the worst - it's really hard to unlock with my thumb, so I usually do it by pulling the lockbar with my index finger instead.

The Ikuchi is affected as well. So far it's the only negative aspect I found, and I can bypass it easily by pushing the lockbar with my (cut short) fingernail.

Most spydies don't have it, or it's so little it's not noticeable. But some do. Some designs have inserts on the lockbar (e.g. the Advocate), probably to avoid lockstick by having a different material-on-material contact. So it seems that designers know that some materials have a higher risk for lockstick. In the Advocate they cared enough to design-in a third material to avoid it. But not in the K2 (which wasn't a cheap knife), or the Ikuchi. I know, those are all collaboration models. Do you think the designers didn't care?

The Ikuchi's blade is made of S30V, a widely used steel. I own two more S30V spydies, the Hanan and the Smock - they have no lockstick at all. Because of different materials used for the lockbar? Or a different coating or finish maybe? Why is lockstick not identified and eliminated by switching materials, or by not using materials that have a high risk for it from the start, for sure before release of any knife? It is annoying, and it seems it could be avoided if you look into it.

Re: lockstick - my thoughts and your facts or theories

Posted: Fri Feb 28, 2020 3:16 pm
by curlyhairedboy
lockstick can occur for a bunch of reasons, but it's most commonly seen in titanium/steel interfaces. Titanium as a metal is notoriously bad at thermal conductivity, and it's a bear to machine. It likes to gall and rub off on other materials.

Lockbar inserts are an innovation to create a steel/steel interface and also avoid concerns about ti/steel interfaces causing excessive titanium wear.

Lockstick on compression locks is often caused by lubrication in the wrong place. ideally you shouldn't have any lube on the lockface. However, sometimes a little lube on the stop pin itself can relieve the sticking, especially on models vulnerable to it.

Re: lockstick - my thoughts and your facts or theories

Posted: Fri Feb 28, 2020 3:48 pm
by JacksonKnives
archangel wrote:
Fri Feb 28, 2020 3:01 pm
I Why is lockstick not identified and eliminated by switching materials, or by not using materials that have a high risk for it from the start, for sure before release of any knife? It is annoying, and it seems it could be avoided if you look into it.
This is a bit like asking why road noise isn't eliminated in automobile cabs. The parameters are known, but not easy to predict for each car/knife sold, since the surface we're talking about is breaking in with use and will wear differently with different use.

My Ikuchi doesn't stick, your does. That's steel:steel.
My Sage 2 doesn't stick, your K2 does. That's titanium:steel.
Titanium is definitely more likely to stick, but it's not just about materials. Lockbar tension and surface finish are far more relevant. Tightening screws can also tweak alignment of the parts.

The usual recommendations for pencil lead or other lube are still your best bet.

If it's breaking in the wrong way and adjusting screw tension and lube don't help, there are more drastic measures that an expert could take, but it's tricky business that could do more harm than good in the wrong hands.

Re: lockstick - my thoughts and your facts or theories

Posted: Fri Feb 28, 2020 4:20 pm
by DSH007
The only knives that I recall off the top of my head that had it pretty bad were the Lil Sub Hilt and the Spydiechef.. both were pretty easily remedied by a short break-in period.

Re: lockstick - my thoughts and your facts or theories

Posted: Fri Feb 28, 2020 4:26 pm
by Evil D
Years ago I was at a knife shop fiddling with a ZT, it was assisted opening and it opened so hard and has so much lock stick it took me pressing with both thumbs to unlock it. For me, with only a couple exceptions, if it's a frame lock without a steel insert I'll pass. Otherwise I won't think I've ever had lock stick on other locks, maybe on a compression lock but I don't even remember which one so it couldn't have been a big deal.

Re: lockstick - my thoughts and your facts or theories

Posted: Fri Feb 28, 2020 4:52 pm
by archangel
I admit I haven't tried any of the possible remedies, so far I have lived with the lockstick. I'm gonna have to try the pencil lead trick on the K2. It's well beyond any breaking in period, has been flicked hundreds of times...

I'm still struggling to understand how steel on steel sometimes sticks and sometimes doesn't. Can it be a result of microscopic surface groves or something that either cant, resulting in stick, or don't?

Oh and by the way: my Slysz Bowie has a titanium frame, no insert on the lockbar, and next to no lockstick.

Re: lockstick - my thoughts and your facts or theories

Posted: Fri Feb 28, 2020 5:46 pm
by JacksonKnives
archangel wrote:
Fri Feb 28, 2020 4:52 pm
I'm still struggling to understand how steel on steel sometimes sticks and sometimes doesn't. Can it be a result of microscopic surface groves or something that either cant, resulting in stick, or don't?
There's the finish, but there's also the angle and the direction the pressure is being applied. Think about sliding down a sloped glass surface wearing leather-sole shoes. Just a little change of angle will totally change the amount of slip/friction.

Lockup is even influenced by assembly, in my experience, though I can't say I've ever fixed lock stick by disassembling and re-assembling a knife. (Though the same forces that act on centering should influence stick to some degree.)

Re: lockstick - my thoughts and your facts or theories

Posted: Fri Feb 28, 2020 7:40 pm
by Matt Deaner
I think the problem is galling. Asperities in the blade steel dig into the titanium lock face and cause the interface to stick on release. I have used powdered graphite with some success, but the best fix I have found is simply reducing the lock tension. All three of my modded / reground k2s have been done this way, and they don’t stick. Same with my spydiechef.

Re: lockstick - my thoughts and your facts or theories

Posted: Sat Feb 29, 2020 3:00 am
by archangel
Thanks guys. OK, I think I get it - there can be multiple root causes. Like I said, I do find it a bit annoying, but not that annoying so that I have to do something about it, except for maybe on my K2 where I will now try the pencil trick.

Three K2s, wow...

Re: lockstick - my thoughts and your facts or theories

Posted: Sat Feb 29, 2020 3:28 am
by Pancake
Guys, you are all wrong.

Lockstick was created by evil finnish spirit Perkele ( sometimes called also Perkelesaatana). This spirit can come to your home at night and create a lockstick.
:D

Re: lockstick - my thoughts and your facts or theories

Posted: Sat Feb 29, 2020 6:19 am
by archangel
Pancake wrote:
Sat Feb 29, 2020 3:28 am
Guys, you are all wrong.

Lockstick was created by evil finnish spirit Perkele ( sometimes called also Perkelesaatana). This spirit can come to your home at night and create a lockstick.
:D

Pancake, that's neither thought nor fact nor theory - that's wrong dosage of medication! ;)

Re: lockstick - my thoughts and your facts or theories

Posted: Sat Feb 29, 2020 9:29 pm
by SpyderGrill
I have a Para 3 CTS-XHP with lock stick. Flipped it hundreds of times, tried the sharpie marker trick and seemed to be better. Now back to where it started, audible loud click and rough on the finger pushing the compression lock.

My Caribbean, Shaman, and Lil Temperance are normal.

Re: lockstick - my thoughts and your facts or theories

Posted: Mon Mar 02, 2020 6:41 pm
by kodai78
Has anyone tried voiding there warranty by disassembling their knife and polishing the lockface? That seems like it would work. ( I’m joking ). If you do have lockstick can you send it to Spyderco?

Re: lockstick - my thoughts and your facts or theories

Posted: Tue Mar 03, 2020 1:39 am
by rabbitanarchy14
kodai78 wrote:
Mon Mar 02, 2020 6:41 pm
Has anyone tried voiding there warranty by disassembling their knife and polishing the lockface? That seems like it would work. ( I’m joking ). If you do have lockstick can you send it to Spyderco?
that is honestly what i did to my lil native and para 3 s30v first run. but i have modded many knives and have a firm grasp of what not to do.

Re: lockstick - my thoughts and your facts or theories

Posted: Tue Mar 03, 2020 6:20 am
by FK
Years ago, I owned 9-10 CRK Sebenza knives,, 2 had lock stick. Applied the CRK grease and eliminated any stick.
CRK does harden the titanium lock face with heat which helps greatly.

Now have 100% Spyderco, only one PM2 early issue has slight stuck.

Regards,
FK