AD 20.5 issues. . .

BP Green

BP Green

I do what I want! When I’m allowed to.
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Oct 23, 2010
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So last week I purchased an AD 20.5 milled ti slicer. It’s a really nice knife and I totally love it. Unfortunately it had some niggling issues. I think I got ‘em mostly worked out, but there’s still one that I’m wondering if it’s normal or something I need to address?

Seller says he purchased it at the blade show in Dallas. Funny old guy but that’s neither here nor there and this isn’t a rant about him. He was totally willing to work with me if I had wanted to return it so no worries there.

Anyway, when I received the knife it was almost locked up. I could sort of get the lock tab to move back and forth slightly, but the blade didn’t want to deploy in either direction. Long story short, I took it apart and the spring wasn’t sitting in the housing correctly. It was bowed out of its slot and that is what was causing the issue. Also there an excess of oil everywhere and some lint but I got it all cleaned up and put back together correctly.

The issue now is that it seems the spring tension is pretty strong. It takes a lot of effort to pull that lock back. Every video I see with these knives it looks like the action is super smooth and and easily slides back and forth with a flick of the finger. Mine requires gorilla strength, and not just backward, but a backward and up motion. It’s pretty rough on the finger tip and nail.

I’m just wondering if it’s reasonable to assume it’ll get better with time if I keep working it, or should I maybe order some more springs from Demko? I mean, I’m going to do that anyway just to have them so that’s a moot point I guess.

For those of you that have one, what do you think? Is yours pretty easy to operate, or does it require a lot of force? Is it a simple back and forth movement, or is it a back and up motion to unlock the blade? I got it working fine except for the amount of force required to operate the lock. I can’t even do it with my left hand. I’m sure I can eventually get it working ok, probably just by buying a new spring but just wondering how yours feels?

I can provide pics of the lock but it looks like every other lock I’ve seen in a multitude of YT videos.

Here a gratuitous pic of the knife however, thanks!: 😁
image.jpg
 
Don't own any 20.5 models, but have a bunch of full 20 models. The lock is indeed, ridiculously easy to manipulate. At its core, it's a simple piece of engineering. Is it possible the previous owner messed around with is knife, and changed the bearings? Maybe the tolerance has changed, which is somehow allowing the scales to compress against the lock, in some small way? Or he got a bunch of lock-tight between the lock and frame. Just take the whole thing about, take a look, and see.
 
oliveview said:
Don't own any 20.5 models, but have a bunch of full 20 models. The lock is indeed, ridiculously easy to manipulate. At its core, it's a simple piece of engineering. Is it possible the previous owner messed around with is knife, and changed the bearings? Maybe the tolerance has changed, which is somehow allowing the scales to compress against the lock, in some small way? Or he got a bunch of lock-tight between the lock and frame. Just take the whole thing about, take a look, and see.
Click to expand...
Yeah, I’m about to take the whole thing apart again something is definitely up. Thanks!
 
I'd check and see if the hardened washers are in the bearing pockets inside the scales. All titanium Demkos that I have seen have washers in there for the bearings to ride on so they are not riding directly on the titanium. I've had a knife act like that if the washers were missing and also if it needed another .005" spacer on either side. If nothing else, Email support@demkoknives.com and they will probably be happy to help you get it fixed!
 
its not normal. I got 2, 20.5s. the 20.5 aint much different spring tension feel than the ad20's i own. somethings amiss. if ya cant figured it out sure the fellas at Demko can help ya.
 
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Thank you guys. I emailed Demko with the issue and currently awaiting a response. In the meantime, I’m going to take it apart again. This one does have washers and the blade is perfectly centered when closed. I’m thinking there’s definitely something up with this spring because the blade swings freely when I do pull the shark fin back and up. It just takes some gorilla strength to do it.
 
It was still a little dirty. I didn’t do a thorough job when I took it apart the first time thinking the issue was just the spring not being situated in the housing. I just cleaned it up again and put it back together but still having a problem with excessive spring tension.
 
Make sure that the scales and lock bar are clean. Like really clean. Use acetone or alcohol if you have it. No lube in between there.
 
If there is any pitting or roughness on the lockbar or scales, that will also affect the action.
 
Not sure what other 20.5 springs look like, but at least in your photos, that thing looks quite stout. More like something you might find in a 1911 slide lock / safety tube.

Edit: Further, Shark Lock springs are notoriously easy to have shoot across the room. It wouldn't be impossible to imagine the previous own lost his, and simply replaced it with something he had around, or found in the hardware section at ACE.
 
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Sharp & Fiery said:
Make sure that the scales and lock bar are clean. Like really clean. Use acetone or alcohol if you have it. No lube in between there.
Click to expand...

jlauffer said:
Does the lockbar slide easily without the spring?
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Ok, so the thorough cleaning definitely did help. Yes it does slide as it should without the spring. Honestly guys, I think it’s just that spring is one strong SOB.

If I pull it back and up the blade drops and swings like it’s on air. But the lock has to come all the way back and up and it takes quite a bit of force. I’ll see what Demko say when they get back to me. If they can’t help me I’ll just buy some replacement springs and go from there.
 
oliveview said:
Not sure what other 20.5 springs look like, but at least in your photos, that thing looks quite stout. More like something you might find in a 1911 slide lock / safety tube.
Click to expand...
Honestly, the thought occurred to me that this is not the original spring.
 
Does anyone else have a photo of a spring? I’m thinking that you are correct. That looks like a pretty beefy spring.
 
I have 2 of the 20.5’s and have had them apart multiple times for putting in stand offs, etc. They are extremely smooth. The springs I have measure .9785”
 
Not to mention the OEM coils don’t look nearly as stout. Of course that’s hard to gauge in a picture but I think we might be on to something.
 

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