Can anyone explain the Reverse S shape?

[DelicateEndurance]

I am familiar with karambit type knives. I have a Blackhawk Garra II, which I'm seeking to replace. I was thinking of something like the Harpy or the Byrd Hawkbill. Then I saw the Matriarch II. And, then, the knife shop in my area here apparently received a whole crate full of Civilians, because they start appearing in the glass cabinets of all of them.

I dismissed the Civilian out of hand as being simply too large for day-to-day carry. (It would have been a nice addition to my collection, but I don't like to collect knives, only for them to be safe queens. I want to carry them at least some of the time.) The Matriarch II, being the same size as an Endura, is much better.

However, I'm not sure about the mechanics behind the Reverse S shape of the blade. What exactly is the extra bulge in the blade suppose to accomplish, as opposed to the traditional karambit's simple concave curve? In other words, is there some advantage the Reverse S shape has over the Karambit shape when it comes to the slicing and dicing of flesh?

[Blerv]

The more extreme the shape the more specialized the tool. A reverse s offers some belly for more effective push cuts and sawing. The shape tends to mesh well with curved objects putting more edge to the area. This leaves long and more shallow slices from what I understand.

A hawkbill or traditional kerambit has a lack of belly. The tip does most of the job and it tends to dig deeper trapping objects to the edge.

Both offer a ton of aggressive cutting compared to say a drop point. One is just more a hybrid than a tip with a handle.

[Bill1170]

The reverse S is designed for maximal SD effectiveness in a slashing motion. The tip hooks into the target and the belly is pulled into the target by the tip hook action, cutting deeply without the user needing to arc the wielding wrist through many degrees to maintain pressure while slashing the target. It is very specialized geometry for a specific purpose.

[BAL]

Pictures please. .... Actually just kiddin'

[Michael Janich]

Based on the live-blade cutting I've done on meat targets and other media, the primary advantage of the Reverse S is that the "belly" near the heel of the edge cuts far better than a continuous concave edge--especially in ballistic cutting. With a traditional hawkbill, you typically make contact with the point first and pull the material into the lowest part of the concave edge. You rarely end up making contact with the heel of the edge, which becomes a bit of a "void" in the cutting function.

The belly of the Reverse-S fills this void and allows the edge to make contact--especially if you train to engage with the heel of the blade to maximize use of the entire edge. As you continue your cutting path, the belly loses contact right around the time that the point starts to engage. The remainder of the cutting stroke then functions like a traditional hawkbill.

This blade shape also makes pressure cutting more effective by, again, allowing you to cut effectively with the heel of the edge before the hook engages. If you did this with the heel of the edge of a traditional hawkbill, the blade often hooks too deeply and snags.

The Reverse-S also allows the hawkbill concept to be incorporated into a longer blade without turning the entire knife shape into a banana and ruining the ergos of the handle. Basically, it puts a hawkbill at the far end of a more conventional blade.

The Matriarch2 is my favorite expression of the Reverse-S and, in my opinion, maximizes the cutting potential of the Reverse-S concept.

I hope this helps.

Stay safe,

Mike

[DelicateEndurance]

Yes, it certainly does. Thank you. Given that my favourite knife is an Endura, if I were to get a Reverse-S blade, it will be a Matriarch as well. I don't see the need to go bigger and get a Civilian.

[jackknifeh]

I've seen pictures of knife edges similar to this but opposite. The concave part was near the handle and the end of the blade had a normal belly/tip shape. I always liked the idea of this shape. The concave near the handle would be good for rope, like a normal hawkbill. But you would still have a "normal" belly/tip portion of blade. I even ground a beater fixed blade to this shape. I tried it out and it worked great just like I figured. But, I haven't decided to grind my normal EDC knife blades like this for a couple of reasons. The MAIN reason is I'm not skilled enough to do a job I'd be proud of.

Here's an example of a knife I thought about buying a long time ago. It is a big knife. Then I saw it on a video once being shown by a small, petite girl. The knife looked ENORMOUS. :) Anyway, I think the edge shape could be useful for people on shrimp boats where rope and nets seem to be everywhere. :)

http://www.mantisknives.com/Product%20Z ... Zmora.html

[phillipsted]

Based on the live-blade cutting I've done on meat targets and other media...

"Meat Target" would be a great name for a rock band.

TedP

[Blerv]

It would be interesting if Spyderco played a bit with negative blade angle on the Reverse S models. I know geometry is already favoring the design but a bit more angle should make even more aggressive (albeit look more odd).