Yo2 Question

chuck_roxas45 · #1

For those who have their Yo2 in, I'm seeing what I think is a slight curve on the Yo2's edge from all the pics I've seen. Is this an optical illusion or is there an actual slight curve? Thanks.

pmbspyder · #2

chuck- got mine last night. I believe it's just the imperfection in the way that each is hand sharpened at the end of the process. did several tests with mine and it's straight all the way through. human imperfection is what i would chalk it up to.

would there be a + or - if it was slightly angled, or is it just a general inquiry?

Mako109 · #3

Just received mine about 2 hours ago. From the ricasso, the edge curves in just a fraction of a millimeter (barely noticeable and not an issue at all), then runs perfectly straight all the way to the tip.

Another plausible explaination for the curve you see in the photo is camera lens distortion, particularly if the photo was taken with a compact zoom camera, or using a wide angle lens on a DSLR.

chuck_roxas45 · #4

pmbspyder wrote:chuck- got mine last night. I believe it's just the imperfection in the way that each is hand sharpened at the end of the process. did several tests with mine and it's straight all the way through. human imperfection is what i would chalk it up to.

would there be a + or - if it was slightly angled, or is it just a general inquiry?

Thanks for the replies, guys. @pmbspyder: It would probably keep the edge on the material better in a slash, if there were a slight negative angle. But then, I'm not a knife designer so I'm probably wrong. :)

Tdog · #5

Mine came in today....YESSSS :D and I think that slight curve you are seeing pictured may be from sharpening of the blade or just in the proto? When I place mine open on a flat surface with the knive level there is no curve whatsoever. There are a couple of observations I have regarding this knife. The metal while S30V seems to be a finer grain/grade than other S30's I have. Perhaps because of the thicker stock and wharncliffe design? Mine is also a slightly different "color" (not as silver)as other S30's I have. I wonder if the heat process on this was slightly different? I'm curious if the RC is on the higher end for this particular steel? The shape and length of the blade really lends itself to fine stropping. Mine came very sharp out of the box. The action on the Yo2 I received is a little tight however I'm sure that will change with use. I also noticed the inside edges of the G-10 scales have a slight sharpness to them. This can be easily remedied.

The knife fits very well in the hand. As with all Spyderco's the lock-up is very solid. While I don't have the original Yo to compare to this is a very nice knife. Looking forward to other's observations.

chuck_roxas45 · #6

Now, I'm even more impatient for mine. :D

eloreno · #7

I think you may be on to something chuck.
In the picture below, you can see light coming thru under the blade, which is pressed firmly as flat as possible on a hardwood table.

Jay_Ev · #8

eloreno -

Are you absolutely sure it's the Yoji that is slightly curved? That looks like a wood surface, and wood can warp, bend and buckle with simple changes in humidity. Just curious.

I just got one yesterday and it's as straight as an arrow. I will add this, however: the round hole is slightly occluded so if you are the type who likes 100% access to the opening hole, this may concern you.

Onionman · #9

Put mine up against a credit card, and a slight gap was noticeable near the tip. Wouldn't have noticed it if I wasn't looking for it though. I did notice from the photo above that my Yo 2 has a much finer point. Don't want to stop carrying it, but I'd hate to lose that point.

eloreno · #10

Jay,

Yeah it's wood. Adnd it absolutely could be warped. The reason I even tried this was it seemed to me that the blade was not completely straight. I have since run out to the garage, got a brand new steel ruler, and tested. The blade does appear to be perfectly straight.

eloreno · #11

Onionman,

The pic of mine above is a little misleading. Mines got a pretty fine tip. Not mini dyad plain edge pointy, but just right. I put some more pics in the other yojimbo thread.

syphen · #12

I think every spyderco wharncliffe blade I own has a very very minor curve. This goes for my Urbans, PE Rescue, and Flatbyrd. Have a couple Yo2's coming in a few days. I'm assuming they will have something similar. It doesn't bother me.

BAL · #13

I think that it's just the way that it is sharpened, especially at the tip.

#14

Hey, Guys:

Thank you for your enthusiasm for the Yo2.

By design, the edge is perfectly straight; however, like all US-made Spyderco products, the final sharpening of the Yo2 is done by hand. The slight curve of the edge is a product of that human process.

The craftsmen in our factory who do our sharpening are incredible. They sharepen by eye and by feel and hold edge angles to within one degree. It's absolutely amazing to watch. As good as they are, sharpening the Yo2 is a b_tch. The reason is that the human body is meant to move in arcs. We don't do linear very well--except for straight reaching and pulling. When you have a straight edge that is wider than the belt, it requires lateral movement across the belt to sharpen it. Keeping that lateral movement perfectly linear is actually way harder than "riding" the curve of a typical blade.

With that said, the variances I've seen in Yo2 edges are so minute that unless you lay them on a perfectly flat surface for comparison, you'd never know. More importantly, those variances have absolutely no effect on the knife's cutting performance.

I take pride in knowing that my factory edge has the character of having been tuned by an expert craftsman. If it's more important to you to have an absolutely straight edge, break out the flat stone and make it the way you want it to be. If you use the knife the way it's intended, you'll eventually have to do that anyway.

Thanks again for your enthusiasm.

Stay safe,

Mike

syphen · #15

Great reply and thanks for explaining that, Mr. Janich.

Hope a trainer comes along. I really am enjoying my Yo2 so far. (Short experience).

Question for you Mr. Janich; Do you edc your own designs ie Ronin/Yojimbo or your custom Endura's more often? :)

Dr. Snubnose · #16

Glad MJ gave you the answers you were looking for, I was going to chime in and say...don't worry about it...it's has been the same thing for all the Yo1 and Ronins I have owned...But he said it better

...Doc :D

Donut · #17

I have a heck of a time sharpening straight edges on a bench stone and on the sharpmaker (have to only use the corners). It would probably take a guided setup to sharpen it well.

BAL · #18

Michael Janich wrote:Hey, Guys:

Thank you for your enthusiasm for the Yo2.

By design, the edge is perfectly straight; however, like all US-made Spyderco products, the final sharpening of the Yo2 is done by hand. The slight curve of the edge is a product of that human process.

The craftsmen in our factory who do our sharpening are incredible. They sharepen by eye and by feel and hold edge angles to within one degree. It's absolutely amazing to watch. As good as they are, sharpening the Yo2 is a b_tch. The reason is that the human body is meant to move in arcs. We don't do linear very well--except for straight reaching and pulling. When you have a straight edge that is wider than the belt, it requires lateral movement across the belt to sharpen it. Keeping that lateral movement perfectly linear is actually way harder than "riding" the curve of a typical blade.

With that said, the variances I've seen in Yo2 edges are so minute that unless you lay them on a perfectly flat surface for comparison, you'd never know. More importantly, those variances have absolutely no effect on the knife's cutting performance.

I take pride in knowing that my factory edge has the character of having been tuned by an expert craftsman. If it's more important to you to have an absolutely straight edge, break out the flat stone and make it the way you want it to be. If you use the knife the way it's intended, you'll eventually have to do that anyway.

Thanks again for your enthusiasm.

Stay safe,

Mike

Thanks Mike, for your comments and information on this forum. I had yesterday off and finally took the time to watch the Practical Blade Defense DVD that I picked up from the MBC website when I ordered your Custom Endura, which I had been carrying as a SD knife. I say had been carrying, because when I got to the office this morning, there on my desk was a package that contained the Yo2.

Wow, when you hold the Yo 2, it's obvious that you put many hours into it's design. It feels natural to hold, like an extention of your hand. It's the baddest 3 1/8" blade that I have ever seen. The pictures that I have seen of the Yo2 are impressive, but don't do it justice. I'm not trying to be a kiss-up, but the Yo2 is an awesome overall knife that should find its way to the pockets of anyone reading this.

Thanks again and Stay Safe.

DCDesigns · #19

Donut wrote:I have a heck of a time sharpening straight edges on a bench stone and on the sharpmaker (have to only use the corners). It would probably take a guided setup to sharpen it well.

I imagine the sharpmaker would be pretty hard. If you have a big wide bench stone, I dont see what would be so difficult. If its as wide as the blade, wouldnt it be just forward movements keeping it flat on the stone? Seems to me like that might be the easiest thing you'd ever sharpen. If the stone is thinner than the blade is long, I could see how that would be difficult.

Mud Shrimp Moe · #20

DCDesigns wrote:I imagine the sharpmaker would be pretty hard. If you have a big wide bench stone, I dont see what would be so difficult. If its as wide as the blade, wouldnt it be just forward movements keeping it flat on the stone? Seems to me like that might be the easiest thing you'd ever sharpen. If the stone is thinner than the blade is long, I could see how that would be difficult.

The way I read it, there's probably similar variance in sharpening a curved blade too. However, you're far more likely to notice slight variance in a blade that's supposed to be perfectly flat than in one that is supposed to have some curve in it.

In any case, my Yo2 should be with me by week's end. Can't wait!