Trying to understand the attributes of negative blade rake.

[Grizzly]

I've linked this excellent review from 2015 which came up during a search where I was trying to understand why so many of the long Spyderco knives have such a negative rake to the blade.
viewtopic.php?f=2&t=70023&p=1071446&hil ... V#p1071446

Having lost my PM2 after using it for over 5 years, I was looking for a replacement. Part of my search involved the "What's your favorite large Spyderco folder?" thread and this photo which vivi provided:

You can't see it very well in that photo, but even the Endura at the top has a very noticeable negative blade angle in my hand. The Military and Police have an even more pronounced negative blade angle. Now the Manix xl which so many love would be perfect for me if it were not so wide. I imagine the full leaf blade demands that though. The Manix xl seems to have a fairly neutral blade angle which is closer to the PM2 which I was comfortable with.

I suppose that in time - which affects so many things we are not accustomed to and allows us to adapt - I might warm up to these neg rake knives and understand what advantage they provide over the "sharpened railroad spike" that Ed Schempp refuses to design or work with but which many of us have spent our lives using and have grown comfortable with.

So what I'm asking is why do so many enjoy this neg rake design and what are its advantages for everyday carry?

Trying to warm up to it, I took my daughters Endura over to the cutting board in the kitchen and saw how only the most forward part of the blade would contact the cutting board. With more blade rake this becomes even more pronounced. It seems to me that this would make cutting your steak in a restaurant a bit awkward which if I understood what I read was part of the reason the Police was created in the first place.

Please share your experiences of how this design functions well in your daily routines over a more neutral angled blade design or even other special uses you may put them to.

[vivi]

Outside of cutting board duties, where I use chef knives anyways, I find negative blade angles increase cutting leverage and ergonomics.

When I use a straight bar style knife, like say a Mora or Kershaw Skyline, I notice two things.

First, I'm angling my wrist down like I'm giving a hand shake to make them cut better.

Second, things seem more likely to slip off the tip end while slicing materials.

Knives with a more drastic negative angle seem to focus material towards one part of the cutting edge when doing slicing pull cuts - which is the type of cut I use most often with a folder.

Having the knife already angled means I can keep my wrist at its natural angle, which decreases long term fatigue. This is one of the reasons I went back to EDCing a Military.

I find the negative angle of the Police 4 and Military to be about ideal for me. Endura and Chief have a bit less than I like, and jury is still out on something like the Ayoob.

When using these knives on a flat surface, like your example of cutting a steak, I find what works best is to focus on slicing with the belly towards the tip. I find my Police and Millie can slice meat on a flat surface using that area of the blade and I can avoid getting the pivot dirty because of the generous sized blade.

If I were going to prep food with one of the knives in my photo, I'd pick the Manix XL or Chief. Chief has excellent geometry and not too drastic of an angle. Manix XL has nice handle heavy balance which increases control, a very nice blade shape for cutting board work, and less angle than the Millie & Police.

You're right about the Endura. It looks pretty neutral but when you grip the handle it pushes the blade to a more negative angle.

[PeaceInOurTime]

Negative blade angle (ETA: and negative tip placement) is one of the primary attributes I look for in an EDC nowadays.

Vivi said it well. Unless you're using your knife on a cutting board, "NBA" is the way to go, IMO -- and even then, I've used my negativity angled blades (even wharncliffes and hawkbills :eek: ) on a cutting board without difficulty. NBA allows you to keep a more natural, comfortable grip angle for typical cutting, including using the tip of the blade on a cutting board at ~waist height.

[Notsurewhy]

A slight to moderate negative blade angle is useful unless cutting against a surface. I'm somewhat confused a bit by your issues, as I've always considered the pm2 to have a slightly negative blade angle.

You could try a kapara for a more neutral angle if that's what you're looking for. Spydiechef if you want to go positive.

[SG89]

Pattada is large and positive too

[sal]

Hi Grizzly,

Those of us that design knives with a negative angle feel they are more ergonomic and one doesn't have to bend your wrist down when using the knife. If you draw a straight line from the tip of your Para 2 through the pivot, you will see that it has a pretty strong negative handle angle. Bob Terzuola and I used to have that argument regularly and was the reason we made his design our first collaboration.

I've been accused of designing in the dark and some say that the knife "looks" better with a straight handle and blade. I really don't look at my knife when I'm cutting. so looks don't carry much weight. I'm "feeling" the ergos. One of the arguments for a Warncliffe blade is that the tip is easier to start the cut because one doesn't have to bend the wrist to get the point down.

sal

[skeeg11]

Not gonna say negative blade angles are overrated as their popularity is evident in Spyderco's lineup. I do think push cutting is very underrated almost to the point of a lost skill set.

[Grizzly]

A slight to moderate negative blade angle is useful unless cutting against a surface. I'm somewhat confused a bit by your issues, as I've always considered the pm2 to have a slightly negative blade angle.

You could try a kapara for a more neutral angle if that's what you're looking for. Spydiechef if you want to go positive.

Yes, I agree, the PM2 is slightly negative, but not enough to feel uncomfortable. Even a Kershaw Blackout is slightly negative and they never bothered me either. Many folders are slightly negative and I've probably become accustomed to that. But, compared to the Endura, Police and Military there is a very noticeable difference. The Endura just feels strange in my hands. But I'm beginning to see how some have used that to their advantage.

What can I say. I grew up with pretty much straight knives. Even my machetes are straight but I can see how the weight forward models could be an advantage. I also see how draw cuts, which when you think about how we use most of our pocket knives, a nba could be an advantage.

Even an older Camillus Stockman 3 blade folder's main blade is slightly negative. But, those knives back in the day when I really gave a pocket knife a workout was used for much more than just draw cuts. I really don't think back in the late '60's and early '70s when the stockman was worked pretty hard that I would have wanted a radical negative angle to the main blade. The sheepfoot blade was used nearly as much for all kinds of detail work. If someone would have come up with a way to have locked all three blades when opened, he'd have done well. I remember some with a lock on the main blade, but that's all.

For now I have an Endela in K390 coming but in time I know I'll have to give one of these knives a try. I think I'd prefer the back lock of the Police to the Millie but I'll have to keep looking. I also think I'd miss that raised spine absent on the Chief for the thumb to lock into but my short list was between the Chief and the Endela. That, plus my daughter with the Endura is very curious about the Endela and I wanted to try the K390, so that's mostly what weighted my choice.

[skeeg11]

The pervasive popularity of negative blade angles is due to all you cardboard cutters out there. :p :D

[Doc Dan]

I'll tell something else about a negative blade angle. If there is something you need to cut and you start the cut towards the heel of the blade, that negative angle forces the blade through the material with less effort. It drives the forward curved part of the blade and the tip deeper, if that makes sense. Try it and you will see what I mean. Whereas on a straight, no angle blade, you must push your wrist into the action to keep the blade in contact with the material and it does not easily cut deeper.

[Evil D]

It increases leverage, improves ergonomics, helps to prevent material from slipping off the blade. It's almost a mandatory feature for me. Having the edge lower than my grip is part of it but also having the blade tip lower so I don't have to crank my wrist around to get the tip onto something is a bigger part of it. You use a feature like this every time you use a chef's knife, it may not look the same as a negative blade angle but the edge is much lower than the bottom of the handle and the effects are the same. Get yourself a thin upswept boning knife and see how the ergonomics compare for slicing veggies vs a chef's knife. In my experience most features that make a knife perform better in food prep will make for a better user overall.

[mark greenman]

So what I'm asking is why do so many enjoy this neg rake design and what are its advantages for everyday carry?

The negative blade angle (NBA) requires less wrist bend to apply the blade into pulling cuts. And if the glade is more curved, this effect is increased as the curved edge plus negative blade angle allows a lot of edge to be put into the material.

This review I did years ago of the Spyderco Ayoob - one of Spydercos most aggressively NBA - goes into all the ways thats helpful:

viewtopic.php?t=45380

Its to the point now where the only 'straight' knife I'd be interested in would be a dagger or stiletto. For general EDC / Utility work, NBA such as that found in the Military, Ayoob, and other models, is really the way to go.

[Wartstein]

Nothing to add when it comes to reasons, since all has been said better than I could already.

Just that I clearly prefer negative blade angles over neutral or even positive ones too FOR the reasons mentioned already.
I definitely liked the more negative blade angle of my Millie over the a bit less negative on my Enduras, and I would not consider folders like the Spydie Chef cause of the apparently rather positive angle (unless I´d specifically get it for mainly cutting on a board, which is very unlikely for a folder as main task).

[JRinFL]

Presented without bias as I don’t own one, but the Sebenza, a knife that is the grail for so many, appears to be a neutral blade angle knife.

[Notsurewhy]

Long post, I'm sure I'm wrong in the details so forgive me, but this is how I understand it.

Most people do a lot of draw cuts with pocket knives. The problem with doing draw cuts with a neutral/positive blade angle is once you get to the belly, you're applying less force perpendicular to the material being cut which reduces cutting effectiveness. In addition, the material can slip off the blade without being cut.

This can can mitigated in several ways, each has drawbacks:
- wharncliffes have the same cutting power all the way to the tip, but you lose the functionality of a belly
-recurves "pull" the material being cut into the blade, but you add complexity to sharpening unless you use a rod based system
-hawkbills draw cut like nothing else but don't work for any other type of cutting. You have the drawbacks of both the recurve and the wharnie.
- serrations act like many mini recurves but often cut less cleanly and sharpening issues
- negative blade angle gives you some of the advantages of a recurve without the sharpening issues, but you lose much of your ability to cut against a surface.

Depending on how much draw cutting you do, one of these compromises may be worthwhile, but maybe not. There is no "one blade to rule then all", all good, just different.

Opinion time: Because one of the main strengths of bellied blades (outside the kitchen) is skinning game, and that is not as common a use as it was a generation or two ago*, wharncliffes may be a better choice for many people for edc. This may be why we're seeing so many new models in this configuration.

*My grandma's Betty crocker cookbook showed how to skin a squirrel.

[skeeg11]

Opinion time: Because one of the main strengths of bellied blades (outside the kitchen) is skinning game, and that is not as common a use as it was a generation or two ago*, wharncliffes may be a better choice for many people for edc. This may be why we're seeing so many new models in this configuration.

*My grandma's Betty crocker cookbook showed how to skin a squirrel.

Tis true but sad that we are slowly losing part of our American tradition as time goes by.

For the most part, I prefer blades that can cut both ways. Still, it's nice to have choices in blade configuration. :)

[Notsurewhy]

Opinion time: Because one of the main strengths of bellied blades (outside the kitchen) is skinning game, and that is not as common a use as it was a generation or two ago*, wharncliffes may be a better choice for many people for edc. This may be why we're seeing so many new models in this configuration.

*My grandma's Betty crocker cookbook showed how to skin a squirrel.

Tis true but sad that we are slowly losing part of our American tradition as time goes by.

For the most part, I prefer blades that can cut both ways. Still, it's nice to have choices in blade configuration. :)

Agreed. Where I live hunting is still fairly common, but not as much as it once was. I don't think everyone needs to hunt or raise animals for food, but I think it's good to at least have a bit of first hand experience with were meat comes from. It doesn't just magically appear shrink-wrapped on those styrofoam trays in the grocery store.

As far as personal blade preference , I like to try different options, and have blades in all of the configurations I listed, but a fairly neutral to slight negative blade angle drop point is what I most often carry.

[wrdwrght]

Having to wristcock the angle of a folder toward its work—especially a folder put to a lengthy task—is precisely why I have not pulled the trigger on a Terzuola Starmate (or a CRK Sebenza). Neutral blade-angle is simply a disqualifier for me. I don’t want to approach my typical tasks with a fatiguing grip.

As much as I like my SpydieChef, what it hints in negative blade-angle is cancelled instantly by its upswept cutting-edge. But that upsweep is purposeful—as in purpose-built—and affords easy veggie-prep and meat-carving on a cutting board, especially in a chef’s pinch-grip.

Yes, in various other grips, I could use my SpydieChef to process a caribou or to defend myself, just not ideally. I could also do these things with a last-resort neutrally-angled SAK.

[sal]

The original "Worker" model in 1981 had a negative angle.

sal

[Grizzly]

Has the angle changed much on the Police over the years? From photos, it seems they had less negative angle way before the handle change and re-design.