adrenalized inertia

[mr. v]

Mr. Janich & other experienced knife-flickers,



I've been working on inertia (inertial?) openings recently. I've noticed that sometimes my grip on the handle can squeeze the scales together enough to affect the swing of the blade (d/t increased friction). In a real-life conflict I assume one's grip is going to be pretty firm as a result of the fight-or-flight adrenaline rush. . .does this present a potential problem in using this opening technique?

If so, how can I adapt my training in light of this?



Hope y'all had a good holiday,

Vince



In case this opening is called other things by other people, I'm referring to opening a folder with an outward (palm-down to palm-up) flick of the wrist.

[Michael Janich]

Dear Mr. V:

Thanks for the question. Before I answer, allow me to make it clear that Spyderco does not endorse or recommend the inertial opening of their products and specifically designs them to make such openings extremely difficult, if not impossible. My comments here are offered as an individual knife user and not as a representative of Spyderco.

In response to your question, some knives are susceptible to binding when the handle is squeezed tightly during an opening. This can happen during any kind of opening and is not limited to inertial ones. The primary issues involved are the integrity of the handle scales themselves, the support offered by the handle spacer (if any), and the centering of the blade in the handle slot.

Knives with thin or very flexible handle scales will flex and bind the blade when gripped tightly (traditional Filipino balisongs with folded brass handles are notorious for this). The only real solution is to get a better knife.

Knives with open handle construction that lack a full-length spacer can also have this problem because they are free to flex in the middle. These are usually liner-knives and this style of handle construction usually compromises the integrity of the lock. Again, get a better knife.

Knives with full-length spacers and lockback knives should not suffer from this problem if the blade is properly ground and centered and the inside of the handle properly finished. If these qualities are not present, the blade can bind. A good way to test for this is to use a dry erase marker on the side of the blade and try a few of the openings that cause the blade to bind. Look at the blade to see where the marker is worn off, then turn your attention to the corresponding portion of the handle. If there are burrs on the inside of the handle (a common problem with Zytel handles), a warding file (a small flat file used by locksmiths) can be used to gently file away the offending material inside the handle and free up the blade. If the blade is not centered in the handle when closed, your best bet is to get another knife.

One other suggestion is to adjust your grip on the handle to apply pressure closer to the pivot pin and back of the handle rather than the handle slot. This will allow the blade to turn more freely and prevent binding.

I hope this helps.

Say safe,

mike j