Vertical blade play?

F

Fine 250

Joined
Jul 8, 2016
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I have two Byrd Meadowlark 2's that I purchased for beater knifes. I also have two Delica 4's. Both Byrd's have vertical play and one of the Delica's has play. I assume this is a lock up, geometry issue. Is it possible to correct this? Just curious how many Delica's out there have vertical play? Thanks.
 
It is not uncommon for lock backs to have a little vertical play. The inclusion of a stop pin (like on the Cold Steel Triad lock, or some Spydercos) usually removes this from the equation.
 
my triad locking knives have none my enduras have a tiny bit but really most folding knives are gonna have a little in either direction if you keep it lose enough to be opened fast..... people who really cant stand any play at all should use fixed blades lol
 
Fine 250 said:
I have two Byrd Meadowlark 2's that I purchased for beater knifes. I also have two Delica 4's. Both Byrd's have vertical play and one of the Delica's has play. I assume this is a lock up, geometry issue. Is it possible to correct this? Just curious how many Delica's out there have vertical play? Thanks.
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If it's any consolation, I just shipped a brand new Benchmade Small Summit Lake that is also a back lock to the factory for repair. My wife bought it for me, when I unboxed it and started looking it over, it had some noticeable back and forth blade play plus an off centered blade. As kniferbro said, it isn't uncommon for this to happen, some manufacturers like Benchmade claim a certain amount of blade play is within spec. I also had a Spyderco Endura 4 that had some back and forth blade play. It isn't normal, and if you are uncomfortable with it, the manufacturer needs to fix it. I had a Large Summit Lake that was also a back lock and it locked up as tight as a bank vault with no play whatsoever.
 
I have 4 Spydercos with the backlock. None of them have any up/down bladeplay.
 
Lots of old threads about back locks and vertical blade play on the forum. My Delica 4 has always had some but it's only noticeable when you push quite hard when cutting on a chopping board. It hasn't gotten any worse in the two and a half years I've been carrying it. Slightly irritating but not a safety concern.

I seem to remember a thread from many years ago where Sal referred to it as 'Seki pop' - that almost inaudible click it makes as the Two lock surfaces slide over each other.
 
I can understand the Byrd's having some blade play. Although I have a Cara Cara 2 that also has none like the one Delica. Being that the Delica's cost three times as much I would think the chances of them having it would be less. But it seems like a roll of the dice.
 
Fine 250 said:
Being that the Delica's cost three times as much I would think the chances of them having it would be less. But it seems like a roll of the dice.
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Trust me if that was the case the forums would be full of reports. If I was to estimate the chance of getting a Spyderco lock back with vertical lock rock I would say it's a 0,1% chance of that. Probably A LOT less.
 
Check that the surfaces of the lock and tang of the blade are free of any debris or lint. This can cause bladeplay. I know that in a liner or frame lock vertical play is a SERIOUS problem and indicates that the lock is not correctly built. As for in lockbacks I am not sure. None of my Spyderco Lockbacks have blade play. Generally knives like the Delica and Byrd lockbacks are not meant to be able to be flipped open very easily so it could be you have the knives pivots way too loose for the lockup to function properly. Spyderco lockbacks generally have alot of bias holding the blade closed making them not the easiest knives in the world to flip open. (liner or framelocks are much better locks for that type of flicking action.)

Eventually after much use or by polishing the surfaces a Spyderco lockback will become easier to flip open but generally this takes a long time and lots of open and closings. Judging by what I read it seems that if you are loosing the pivot enough that the knife flips open easily but it is causing this vertical play then you are loosening the pivot too much. Spyderco lockbacks are a bit stiff to flip open NOT because of tight pivots but because the backspring biasing the blade closed.
 
It depends on what you mean by "lock rock."

If you mean does it wiggle a bit up and down with moderate force by hand, you can certainly find a lock-back that does not have it.

If you mean "It does not move at all, even when cutting with all my force, Grraaaahhhhrrr!!! ", then no, you probably won't find one that does not move at all.
You can find ones that don't move much though, and if you never go to full "Grraaaahhhhrrr!!!" level cutting, you may not notice any movement at all. ;)
 
I can tighten the pivot all the way and still holding the knife in my hand create up and down play. The pivot can reduce side to side play however being that the pivot is 90 degrees to the locking surfaces it cannot reduce vertical play. Like I said that is a blade tang to locking surface geometry problem.
Three out of five is 60%. Just lucky I guess.
 
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use a backlock to cut with more than just paper and soft items and will develop play over time. i own maybe over 50 or more backlocks. all brands and many very old, many newer, many brand new.

very few i cant make wiggle a tiny bit. all that ive used as a user knife developed some and more than it came with.
 
I've had 5-6 Enduras in the past and one Delica. I only had one Endura that had up and down bladeplay. After opening it a few dozen times over a few months, the bladeplay disappeared. Might have been dirt in the mechanism.
I don t like lock rock.
 
kniferbro said:
It is not uncommon for lock backs to have a little vertical play. The inclusion of a stop pin (like on the Cold Steel Triad lock, or some Spydercos) usually removes this from the equation.
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None of my Schrade 7OT/6OT/LB7 lock backs, be they USA or Taylor Schrade, nor do my two Buck 110's bought at Wally World, have any vertical play.
Come to think of it, neither does my 3 5/8 inch closed Rough Rider lockback.
Vertical play = something wrong, and to me, is a deal breaker. So is side to side play.
 
afishhunter said:
None of my Schrade 7OT/6OT/LB7 lock backs, be they USA or Taylor Schrade, nor do my two Buck 110's bought at Wally World, have any vertical play.
Come to think of it, neither does my 3 5/8 inch closed Rough Rider lockback.
Vertical play = something wrong, and to me, is a deal breaker. So is side to side play.
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Yeah, not saying it's good, just that it's pretty common and a lot of users have looked passed it and their blades have served them well. I too prefer zero play in any direction, but have come to terms with it on a lot of lock-backs :).
 
I have 2 Spydie back locks, Pac Salt & a Native.
Both are beaters for work, HVAC. I have beat on both hard for almost 2 years and neither moves at all in any direction.
I am sitting in my truck right now trying to move these blades and I get no movement.
Joe
 
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