It's just a trend. On the drawingboard, liner locks look more reliable than lockbacks for hard use folders because when they fail due to closing pressure, they fail open. What doesn't show up on the drawingboard is that liner locks are hard to make so that they have no tendency to release before they fail. Liner locks are also pretty simple to construct, compared to a lockback.
I consider them both about equal in terms of reliability myself.
Steve, I would think that a lockback is easier to construct. Getting the liner to fall just right and with a good fit up would seem to me tougher than doing the lockback. Maybe a knife maker could give their opinion.
Lock backs are tricky to design so the heel of your hand does not release the lock during heavy use. Once you overcome this problem they are very good knives but are not as easy to open one handed as the liner locks.
I think that a lot of guys buy the liner locks so they can play with them flicking them open, closing them, flicking them open,closi................well you get the drift.
It's no harder to open or close a lockback one-handed than it is to open or close a liner one-handed. The technique is different, that's all. Now, if you don't know the technique, that's different, but that's on you. I gave a brief overview of the technique in the "prevalence of 110" thread.
Lockbacks are a good, solid lock that's proven itself over several decades of service. I'm all for a new lock if it's truly superior, a linerlock isn't.
Lockbacks aren't hard to make either. If you do like Buck and have the release bar or whatever you want to call it flush with the handle. Only when there's a little nob poking up is there a problem with premature release.
Hmm, what nob? Anyway, back to the original question...All that keeps a lockback from failing is that itty bitty little pin that it pivots on, besides, they just aren't cool anymore!!!(Excluding Spydy's of course.)
"All of our knives open with one hand, in case you're busy with the other"
<OVAL OFFICE JOKE>
Own? Nope. I don't buy anything till I've thoroughly tested it. I don't buy music till I've listened to it, or books till I've read them either. I've tested many linerlocks from varying manufacturers. I'm not gonna give a capsule review of each, suffice it to say "nothing there for me". I reserve judgement on the newer, more exotic locks as I have not tested them. When I wear out my XlTi(560 or something, not a 110) I will try some of the newer stuff, if there are any knives made with them that offer all the features satisfied by the Buck Titanium, I will buy one of them. I do not hold onto things for the sake of only tradition/sentimental value. Everything I have has proven itself valuable, and anything I aquire must do the same.
The "nob" I refer to is the little lump on the locking bar on some lockbacks that are presumably put there to make them easier to close. Atlanta Cutlery was selling some recently, they have been relatively common for a long time, but since they suck I don't but them so no models featuring such a protrusion comes to mind. Actualy, think of the lockback versions of the "stilleto" style knives, you know, like the Italian switchblades?
1. Don't discount the "fun" aspect of opening and closing linerlocks as mentioned above. I know that there are ways and means of doing the same with a backlock, but it just isn't as natural, or slick as with the linerlock. Guys like to "play" with their knives. The linerlock is like a knife enthusiast's worry-beads.
2. Linerlocks brought the wave of "modular" construction with them that has changed the face of knives in the last 10-15 years, i.e. screw pivot pins, mini-handle screws. One finds very few linerlocks being rivetted together. This led to a hi-tech look as designers started making a "feature" of these fittings rather than trying to hide them away. It's acceptance by the buying public formed much of the springboard for the current generation of tactical folders.
3. Linerlock design can (though not always) provide increased options for blade shapes. Backlocks can often be "limited" by their mechanisms in terms of achieving the desired blade shape -to- handle size ratio.
P.S. I love them, and have them, all . . . liners, backlocks, frontlocks, integrals, springblades, friction . . .
My major problem with lockback doesn't involve strength or reliability by rather wear and tear and loosening of tolerances (which I guess can be called reliability). By virtue of design, liner locks jam the blade against the stop pin and force it forward against the pivot so that it has little to no forward and reverse play (or shouldn't if it's a good one). Even with a good deal of wear the tolerances are secure. My Cold Steel Gunsite folder with a midlock lockback became very loose, though it does have zytel handles. My Spydercos with the same type lock, even though they have stainless handles, developed the same backward and forward blade play. My guess is that over time, the tolerances of liner locks are going to give as well, if used everyday. My axis lock, even though I may have to crack it open and replace an omega spring or two, would seem to be the most resistent to long-term wear (even though I've only had it for several months). So to answer your question more directly, there's nothing wrong with lockbacks at all if you're not a perfectionist freak like some of us.
Why was anyone even looking at lock designs other than lockbacks?
1. Lockbacks can suffer white knuckle failure. When you squeeze a lockback hard, your palm can sometimes hit the unlock button and release the lock. This is highly dependent on the person -- I know some people who swear they only have problems with mid-locks, and others who only have problems with the classic Buck 110-style end locks. There are a number of things the maker can do to eliminate this, such as scooping out the unlock button (ala Boye) or just choosing where to put the release button carefully.
2. Lockbacks are not self-adjusting with wear. As a lockback is used and the locking tooth wears, the lockup first becomes wobbly, then becomes unsafe. Other locks, such as liner locks and BM's Axis lock, are self-adjusting. As the lock wears, it does not threaten the lockup integrity.
3. Lockbacks are a pain to close one-handed. It can be done by using your leg, but that isn't as convenient as the worry-bead type one-handed liner lock action.
Of course, lockbacks had some great strengths, too.
1. A lockback can be made very strong
2. A lockback is ambidextrous
3. The lockback's spring holds the blade closed, allowing for safer carry and the option of tip-up or tip-down clip placement.
4. A lockback can suffer from white-knuckle failures, but only rarely suffers from spine-pressure failures, and (as far as I can tell) never from torquing failures. Less failure modes than liner locks.
By contrast, the BM Axis lock appears to address the 3 lockback disadvantages I mentioned. It also addresses the 1st three advantages, and doesn't suffer from any of the failure modes (so far!!!! testing still ongoing) mentioned in the 4th advantage. However, we've been debating whether there's a failure mode unique to slide-operated locks (like the Axis or Rolling Lock), where the fingers accidently engage the slide and release the lock.
Cliff, I haven't handled my Carnivour extensively yet, but have played with it some. You would think that the Carnivour's lock release button, so close to the index finger cut-out, would be easy to trigger by accident. However, I think this is one of those things that really depends heavily on hand size and shape. My fingers don't seem to curl onto the lock release button, ever. Partially that's because with my relatively small hand, my index finger ends up wrapped around the subhilt rather than properly positioned up-and-down in the index finger groove. I'm gonna guess this is a push, depending on hand shapes. I'm watching the forums waiting to see if other people have problems with one lock release or the other.
One thing I will say about the Carnivour's lock release, it doesn't stick out as far as the Axis's lock release, and it's a little more difficult to engage. I look at that as a good thing -- even if you do end up touching the button, it'll take more force to really get it moving.