How do I restore the resistance on my UKPK?

[buckleys]

Is it inevitable that the spring gets weaker with slipjoints? I bought the HH edition in 2019, but the past two weeks I've noticed there's barely any resistance to break the detent of the half stop now. I disassembled it and cleaned it out then put it back together and it's still kind of weak, and I didn't notice any deformation in the back spring or anything. It still snaps open with a lot of strength, but I barely have to nudge to go from the open position to the half stop, then barely have to nudge again to go from the half-stop to closed.

[sal]

Where are you?

sal

[buckleys]

Where are you?

sal

Hi Sal,

I'm in Toronto, Canada although I purchased it from Heinnie Hayne's online shop in 2019

[Doc Dan]

There is no detent. It uses spring tension to keep the blade open or closed. The spring is double pronged. Is is possible that one of the prongs snapped off? If you didn't see two when you disassembled it then one is gone. That would make the resistance weaker.

[PaloArt]

Truth to be told the same issue I have with my K390 Urban and my AEB-L version and Squeak starts to have way lower resistance as well over time. Somehow it seems that spring, with some time and use, gets weaker in terms of resistance. I can close my K390 just with slight pressure on the spine, one hand opposed to when it was new. I kinda thought, this is somehow normal on those slipits. I can`t disassemble my AEB-L due to spinning pivot pin thought to look inside but springs look ok on remaining two.

I am not metalurgist, but can it be somehow caused by the material used for the spring? My victorinox knives (stainless steel spring), douk douks (carbon steel spring) and Lionsteel Gitano (stainless steel spring) are going still strong even after many years of use and opening and closing.

[Matus]

I have not owned my k390 Urban since new, but it's spring is way weaker than the one one n690co that I got new few months ago. I am thinking of drilling the screws out and put the blade to my new Urban as for now the k390 is collecting dust ad that is a pure shame.

[PaloArt]

I have not owned my k390 Urban since new, but it's spring is way weaker than the one one n690co that I got new few months ago. I am thinking of drilling the screws out and put the blade to my new Urban as for now the k390 is collecting dust ad that is a pure shame.

My experience with K390 is different - it had pretty strong retention of the spring, AEB-L as well. Squeak I have for one year and it had strong resistance\hardness of the spring as well. Now they all are more soft opening. This is good for people who have issues with opening those knives in the beginning due to arthritis for example, more you use it more it "breaks in". Problem is that it had broken in too much I would say. I am not a knifemaker, but perhaps someone with more expertise can chime in why does spring loose the tension after some time...

K390 will not fit probably newer springs since we tried to exchange springs with my friend on Squeak (his was too hard to open one handed, mine was softer). Me knowing it will "soften" tension with time had no issue with this change but it didn`t fit. Between pink squeak, 4 years old, and newer squeak with solution preventing pivot spinning there was as well difference in the spring shape and angle, if that makes sense.

Nevertheless, slipits are still my most carried and used knives from my collection.

[buckleys]

There is no detent. It uses spring tension to keep the blade open or closed. The spring is double pronged. Is is possible that one of the prongs snapped off? If you didn't see two when you disassembled it then one is gone. That would make the resistance weaker.

Right, what I meant was the tension. There's nothing wrong with the fork underneath from what I see.

[James Y]

It sounds like that may be an inherent weakness with the split spring design (?). That maybe it weakens over time? I've had my UKPK Salt for nearly 2 years and it hasn't happened to mine yet. But who knows if it will at some point. If it is an inherent design flaw in the split spring that manifests over time (and for some, apparently not much time at all), maybe Spyderco can look into it and CQI it.

I have slipjoints like traditional and SAKs, many of which I've owned and used for decades, and the backsprings are still as strong as ever.

Jim

[Matus]

I have not owned my k390 Urban since new, but it's spring is way weaker than the one one n690co that I got new few months ago. I am thinking of drilling the screws out and put the blade to my new Urban as for now the k390 is collecting dust ad that is a pure shame.

My experience with K390 is different - it had pretty strong retention of the spring, AEB-L as well. Squeak I have for one year and it had strong resistance\hardness of the spring as well. Now they all are more soft opening. This is good for people who have issues with opening those knives in the beginning due to arthritis for example, more you use it more it "breaks in". Problem is that it had broken in too much I would say. I am not a knifemaker, but perhaps someone with more expertise can chime in why does spring loose the tension after some time...

K390 will not fit probably newer springs since we tried to exchange springs with my friend on Squeak (his was too hard to open one handed, mine was softer). Me knowing it will "soften" tension with time had no issue with this change but it didn`t fit. Between pink squeak, 4 years old, and newer squeak with solution preventing pivot spinning there was as well difference in the spring shape and angle, if that makes sense.

Nevertheless, slipits are still my most carried and used knives from my collection.

Thanks for the warning. Indeed - there are a few years in-between these two Urbans. Maybe I just should covert the k390 one into a fixed blade, or simply sell it to a collector. But the blade on the k390 is just better in every regard. A few mm longer, looks more elegant, thinner behind the edge and, well, is from 390.

[Bemo]

It sounds like that may be an inherent weakness with the split spring design (?). That maybe it weakens over time? I've had my UKPK Salt for nearly 2 years and it hasn't happened to mine yet. But who knows if it will at some point. If it is an inherent design flaw in the split spring that manifests over time (and for some, apparently not much time at all), maybe Spyderco can look into it and CQI it.

I have slipjoints like traditional and SAKs, many of which I've owned and used for decades, and the backsprings are still as strong as ever.

Jim

It is possible the split spring design does have an inherent flaw. However that doesn't explain all the reports in this thread of weak springs. The Italian made slipits don't use split springs, at least the 3 I have don't.

Good news for the OP at least is there's a chance the Golden made UKPK can be fixed. I'm not sure that would be true of the Urbans with weak springs.

[jmj3esq]

I had a weak spring on my Delica M390. I took it apart and bent the spring slightly upward and reinstalled. It had a much better snap after that.

[PaloArt]

It is possible the split spring design does have an inherent flaw. However that doesn't explain all the reports in this thread of weak springs. The Italian made slipits don't use split springs, at least the 3 I have don't.

Good news for the OP at least is there's a chance the Golden made UKPK can be fixed. I'm not sure that would be true of the Urbans with weak springs.
[/quote]

Frankly I made mistake not realizing\not knowing that UK PK has different solution for the spring system, if I had read that more carefuly...

Urban is then little bit different story than UK PK and issue will be absolutely different. Perhaps it might be rounding off\breaking in of the blade tang, that causes this, I do not know. I am interested in buying UK PK then and see for myself if this issue will manifest as well on that knife.

Most definitely it is positive, that Sal immediately replied and is interested in this topic. It would be good to send the UK PK in question to Spyderco for inspection. Good luck to buckleys regarding sorting this out.

[PaloArt]

I had a weak spring on my Delica M390. I took it apart and bent the spring slightly upward and reinstalled. It had a much better snap after that.

Delica and UK PK or any other slip it Spyderco are absolutely different kind of knives, different kind of "lock". I can`t see how trying to bend spring on slip joint would help here unless you are Hulk . UK PK in question is somehow specific slipjoint knife, I am affraid that there will be no bending helpful.