Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
Due to recent exchanges on liner/integral stability compared to lock backs I went over a few to check stability. What I found was fairly large differences in behavior. Specifically I could disengage a Cara Cara readily in an icepick grip, with just a bit of positioning, and hard stabs were kind of problematic as the lock release would be depressed heavily so care had to be used, a quick draw and stab could cause problems.
In comparison a Persian was similar in that the lock was depressed, but it was much harder to do and I had to use highly artifical grips in order to fully release the lock as in turn the blade sideways so the index finger goes right over the lock. Even in heavy normal icepick and inverted grips, the lock refused to give up that last bit, though obviously strength was reduced with the bar partially engaged.
Then I tried the new Delica and it ignored any attempts, even in artifical grips it was very difficult to get the lock to disengage at all and no chance of a full release. Stabs and thrusts didn't induce any opening. I also tried similar with heavy gloves and mitts and found that this made the all the locks more secure.
Examining them to find out why they were different lead to the following conclusions :
1) The Cara Cara only takes 4.5 lbs to disengage the lock as opposed to 6.5 for the Delica/Persian. This isn't a Bryd difference, the Pelican and Meadowlark are also 6.5, I have just reduced the tension on the Cara Cara by subjecting the blade to impacts and prying, there is play in the knife.
2) The lock bar release is wider on the Cara Cara / Persian vs Delica, 2 vs 1.6 cm, and the more narrow bar makes it harder for the finger to hit the bar and not the scales which prevent a release as they can't be depressed. This is also why it is harder with a glove, near impossible with a mitt. People with thicker fingers would also find the locks more secure.
3) The shape of the scales is a large influence. if you note the curve of the lock bar on the Delica it matches closely the hight of the scales. However on the Persian the lock bar release is above them, thus in a white knuckle grip it is depressed slightly before your fingers hit the scales and start resistance.
So a few ways to make the locks even more secure :
1) Increase the resistance, however using my middle, ring and pinky fingers to depress the lock, it would be difficult if the force was increased significantly aside from the thumb and index finger and people with hand conditions and the older and younger people might have an issue, and in general this doesn't seem to be practical.
2) Make sure the lock bar doesn't extend up above the handle scales, in fact lower it if possible and make the release have to go further down into the handle.
3) Keep the length of the opening as small as possible, and make the milled out section as wide as possible.
In general here you are fighting ease of release vs preventing high stress accidental release so not every knife needs the same perspective. A high dress knife may want ease of release and not even have the milled out lockbar.
-Cliff
In comparison a Persian was similar in that the lock was depressed, but it was much harder to do and I had to use highly artifical grips in order to fully release the lock as in turn the blade sideways so the index finger goes right over the lock. Even in heavy normal icepick and inverted grips, the lock refused to give up that last bit, though obviously strength was reduced with the bar partially engaged.
Then I tried the new Delica and it ignored any attempts, even in artifical grips it was very difficult to get the lock to disengage at all and no chance of a full release. Stabs and thrusts didn't induce any opening. I also tried similar with heavy gloves and mitts and found that this made the all the locks more secure.
Examining them to find out why they were different lead to the following conclusions :
1) The Cara Cara only takes 4.5 lbs to disengage the lock as opposed to 6.5 for the Delica/Persian. This isn't a Bryd difference, the Pelican and Meadowlark are also 6.5, I have just reduced the tension on the Cara Cara by subjecting the blade to impacts and prying, there is play in the knife.
2) The lock bar release is wider on the Cara Cara / Persian vs Delica, 2 vs 1.6 cm, and the more narrow bar makes it harder for the finger to hit the bar and not the scales which prevent a release as they can't be depressed. This is also why it is harder with a glove, near impossible with a mitt. People with thicker fingers would also find the locks more secure.
3) The shape of the scales is a large influence. if you note the curve of the lock bar on the Delica it matches closely the hight of the scales. However on the Persian the lock bar release is above them, thus in a white knuckle grip it is depressed slightly before your fingers hit the scales and start resistance.
So a few ways to make the locks even more secure :
1) Increase the resistance, however using my middle, ring and pinky fingers to depress the lock, it would be difficult if the force was increased significantly aside from the thumb and index finger and people with hand conditions and the older and younger people might have an issue, and in general this doesn't seem to be practical.
2) Make sure the lock bar doesn't extend up above the handle scales, in fact lower it if possible and make the release have to go further down into the handle.
3) Keep the length of the opening as small as possible, and make the milled out section as wide as possible.
In general here you are fighting ease of release vs preventing high stress accidental release so not every knife needs the same perspective. A high dress knife may want ease of release and not even have the milled out lockbar.
-Cliff