Do all of your frame locks "bite" into the blade when engaged or is the spring tension keeping the lock bar under the blade all you feel. I recently tried a BM 755 MPR and found that when unlocking the blade it seemed like there was minimal to no contact between the blade and the lock bar. My other frame locks you definitely have to push through a click to unlock the blade. I contacted BM and they said it was normal but it seems wrong to me. Just looking to see it anyone else has experienced this.
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Frame lock question.
- Thread starter ceptor781
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Could be for a few reasons, some of which are cause for concern, others of which aren't.
Starting with the "not a cause for concern" reasons, sometimes the surfaces of the blade tang and lockbar will simply be so smooth or well-matched that, although the lockup/contact is perfectly secure, they disengage with no "stickiness" or "click" at all. A couple of my ZT titanium framelocks have been like this right out of the box, and many others have been like this after they've broken in a bit and/or after I've applied Sharpie to the blade tang.
Another reason, which of course is a cause for concern, would be that there's a problem with the engagement between the blade tang and lock face. At an extreme, it could be that they aren't touching at all, but more likely (that is, likely relative to the "not touching at all" possibility) would be that they're engaging in such a way as to be unstable or prone to slippage/disengagement. A couple ways to test if what you're describing with your BM 755 falls into the "cause for concern" category would be to check for vertical blade play and/or to see if the lock bar slips off the blade tang when you apply firm, consistent pressure to the spine of the blade. (Obviously, with this latter option, make sure to do it in such a way that if the lock does slip off and the blade starts to close, you don't cut yourself. Also, so there's no confusion, I'm not advocating anything like the utterly stupid and useless spinewhack "test" -- all you're doing here is putting your fingers against the spine of the blade and applying pressure to see if the lock slips.)
Starting with the "not a cause for concern" reasons, sometimes the surfaces of the blade tang and lockbar will simply be so smooth or well-matched that, although the lockup/contact is perfectly secure, they disengage with no "stickiness" or "click" at all. A couple of my ZT titanium framelocks have been like this right out of the box, and many others have been like this after they've broken in a bit and/or after I've applied Sharpie to the blade tang.
Another reason, which of course is a cause for concern, would be that there's a problem with the engagement between the blade tang and lock face. At an extreme, it could be that they aren't touching at all, but more likely (that is, likely relative to the "not touching at all" possibility) would be that they're engaging in such a way as to be unstable or prone to slippage/disengagement. A couple ways to test if what you're describing with your BM 755 falls into the "cause for concern" category would be to check for vertical blade play and/or to see if the lock bar slips off the blade tang when you apply firm, consistent pressure to the spine of the blade. (Obviously, with this latter option, make sure to do it in such a way that if the lock does slip off and the blade starts to close, you don't cut yourself. Also, so there's no confusion, I'm not advocating anything like the utterly stupid and useless spinewhack "test" -- all you're doing here is putting your fingers against the spine of the blade and applying pressure to see if the lock slips.)
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You could try rotating the adjustable stop pin so that the edge of the lockbar engages the tang somewhere around 30%. Once you have a somewhat early lockup, just cycle the knife a bunch until it starts to break in. I find the best lockup on a framelock is once the very edge of the lockbar has worn down a bit to 'fit' into the tang more comfortably when engaged.
If that doesn't work maybe there isn't enough spring in the titanium lock bar, like it needs to be disassembled and bent further?
If that doesn't work maybe there isn't enough spring in the titanium lock bar, like it needs to be disassembled and bent further?
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Honestly, as long as the lock up is solid it just sounds to me like the MPR is the one that is actually working correctly and that the rest of your frame locks need to be broken in a bit. A properly broken in frame lock or one with extremely tight tolerances (sebenza...) should not stick or make any click upon disengaging the lock whatsoever.
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as what others have stated...if it takes minimal effort to disengage lock-bar, yet you have no blade-play in any direction, then I'd presume that you have a broken-in frame lock that is now well matched to the blade tang...enjoy it...
Thanks for the input. The MPR went back as it had lock-rock and with moderate spine pressure from my palm the lock bar would begin to move outward slightly. I've had a few other frame locks recently that took minimal effort to unlock and had no "bite" but were stable. However most of my experience is with a BM Mini-Skirmish and a Large 21, they both "bite" fairly well and I've come to like my frame and liner locks this way. I guess I was just wondering if the design is shifting to minimal effort release on new knives.
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Good call -- definitely sounds like the "zero resistance" lock release was indicative of a problem in this case.
That is an easy home fix and is what BM will probably do. And that is to give it more bend in the lock. When your knife does as you describe, slight or continious pressure unlocks it causing the lock bar to spring to the left, then you do not have enough tension in the lock bar to keep it firmly in place.
Of course, when bending a lock bar you must take care and go in tiny increments. I leave the pivot pin in the knives that I do this too and use a Sharpie to measure where the lock bar is before I begin.
Of course, when bending a lock bar you must take care and go in tiny increments. I leave the pivot pin in the knives that I do this too and use a Sharpie to measure where the lock bar is before I begin.
Daniel Dorn
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Does Benchmade still have their "Don't dis-assemble" clause in the warranty? If not, just take it appart, re-seat the washers and screw the thing back together making sure to apply even pressure as you tighten at each point. I had a frame-lock that slid all the way over against the far scale, had a bit of vertical play. After re-assembly, no problem, lock sticks tight, with no wiggle.