Liner Lock vs Lock Back

[THG]

I usually just put my index finger toward the front of the handle, depress the lock with the side of my thumb, flick my wrist so the ricasso hits my index finger, and then reposition and use either my thumb or index to close with the hole.

Same here. It's the same exact number of steps to closing a liner lock.

Liner lock:
1. Disengage lock
2. Move blade down with index finger so that the ricasso stops on the thumb.
3. Bring thumb over and close the rest of the blade

Back lock:
1. Disengage lock
2. Give some forward force to get the blade to come down so that the it stops by the ricasso on the index finger
3. Bring thumb over and close the rest of the blade

I disagree, the situations I noted above do not involve trying to cut with the spine. All of them can, and have, caused locks to fail. While one can argue that a well made liner lock is safer than a poorly made lockback, all things being equal the lockback will be less prone to failure. I would also disagree with your premise regarding the relative ability of a stop pin and a lock bar to withstand the forces transmitted to them in normal cutting.

I didn't catch the situations you listed.

Do you all remember the thread where Vivi (I think) was batonning with his ZDP E4? That's force against the EDGE. The back lock broke. I doubt it would have broken with a liner lock. The problem I see is that the backlock system has 2 components that can fail (lock pin + the lock itself) whereas the liner lock only has 1 (the stop pin itself.) If you have more factors, then you automatically have more chance of failure. It's like saying, "Which is more likely: Emma is a feminist, or emma is a liberal feminist?" Many will say the latter because it seems that they go together, but how can there possibly be a better chance that she fits into two categories rather than just the one?

 

[The Deacon]

Do you all remember the thread where Vivi (I think) was batonning with his ZDP E4? That's force against the EDGE. The back lock broke. I doubt it would have broken with a liner lock. The problem I see is that the backlock system has 2 components that can fail (lock pin + the lock itself) whereas the liner lock only has 1 (the stop pin itself.) If you have more factors, then you automatically have more chance of failure. It's like saying, "Which is more likely: Emma is a feminist, or emma is a liberal feminist?" Many will say the latter because it seems that they go together, but how can there possibly be a better chance that she fits into two categories rather than just the one?

So someone destroyed a midlock doing something no sensible person would do with it. You "think" a liner lock could withstand similar abuse but offer zero supporting data. You count two potential points of failure for a midlock, but only one of them, the pivot pin breaking, could possibly happen from pressure on the edge. Breakage of the bar itself would only happen from down force on the spine, But you then ignore the fact that the same type of down force can cause a liner lock's lockbar to fail by bending it or causing it to slip off the tang. For the record, both locks, and all others, have an additional potential point of failure, the blade pivot itself.

As an aside, the only lock which has ever failed on me was a liner lock on a fairly expensive custom I which I was examining at the NYCKS a few years back. Opened it, pressed on the spine with my index finger, lock slipped, blade closed. Maker's comment was "no problem, I can adjust that"

I think perhaps we'll just have to agree to consider each others views irrational, illogical, and based on anecdotal evidence, and leave it at that.

Paul

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[THG]

You count two potential points of failure for a midlock, but only one of them, the pivot pin breaking, could possibly happen from pressure on the edge. Breakage of the bar itself would only happen from down force on the spine, But you then ignore the fact that the same type of down force can cause a liner lock's lockbar to fail by bending it or causing it to slip off the tang.

If I recall correctly, Vivi's Endura did, in fact, break at the lock bar itself. Perhaps Vivi or Sal can provide some input, since I remember he sent it to Sal for investigation. On the flip side, I have heard of zero stories about a liner lock's stop pin tearing through liners.

For the record, both locks, and all others, have an additional potential point of failure, the blade pivot itself.

True. But then that makes 3 items for potential failure on the lockback compared to 2 on the liner

I think perhaps we'll just have to agree to consider each others views irrational, illogical, and based on anecdotal evidence, and leave it at that.

Nah, I don't think you're irrational or illogical.

And just for the record, I'd choose a lockback over a liner lock every time if I have the choice. I would imagine that a liner lock is going to wear out faster than a lockback system would.

 

[Kenix]

I prefer spyderco's liner locks to pretty much any other manufacturer's liner lock.

 

[forcedestrike]

I prefer spyderco to pretty much any other manufacturer.

I fixed that for you.

 

[Kenix]

I fixed that for you.

Much appreciated

 

[rnjschloss]

Love my emerson linerlocks... and my spyderco backlocks. Use each equally as hard and have not had a failure yet.... but then again I dont use my folders as a machettie or a hatchet.

 

[iamtoast]

I prefer spyderco's liner locks to pretty much any other manufacturer's liner lock.

The Sage's liner lock does not seem the norm for the type. Back locks seem to be more consistent within the industry whereas some liner locks are great (Sage, Military) and other leave alot to be desired (my experience with CRKT m16 etc.).

In general, though I do remember this with the Sage I owned breafly, the ball on the liner creates a bit of extra friction when the liner is released causing the blade to have a third, though minor, detent position. I tend to get caught on this friction point and get my finger nail scraped and sometime cut by the blade. I have not problems opening or closing either type of knife with either hand one handed. The back lock takes more repositioning of the hand and is slower for me. In general, I prefer a frame lock to either and a Ball Bearing, Axis, or Stud Lock type locks are my favorite.

I am thinking of re-purchasing a Sage 1. Does the Sage have the getting stuck on the ball issue?