Disadvantages to convex grind?

[19-3ben]

I hear everyone singing the praises of convex grinds.

As a guy who is relatively new to the intricacies of knife sharpening, just wondering if there are any disadvantages to it rather than a straight V with sharp shoulders.

 

[archieblue]

The only disadvantage I see is that they are seriously ugly. Haha.

 

[VermontEdge]

There's a seriously heated debate going on right now over on the maintenance and tinkering sub-forum. Some people are adamantly in favor of convex grinds and some people think they're much, much worse than a tradition V grind.

Avoiding any blanket statements or comments that might spark another heated debate, I will say that for me, convex grinds have always worked very well. In my understanding, a convex grinds provides a stronger edge as there is more steel behind the cutting edge. Also, IMO, stropping is a really quick, easy and forgiving way to keep knives hair popping sharp. All my knives get touched up on my strop and, as a result (albeit very slowly) they all start to become convexed as I continue on with my upkeep. I've also had Bark Rivers in the past with really terrific convex edges.

All this being said, some V grinds are terrible and some convexed edges are terrible. It's dangerous (especially on this forum), to make blanket statements like "this edge is way better than another type of edge". However, speaking strictly from my own experience, I love convex edges and have never experienced any real disadvantages. As always, YMMV.

If you're new to sharpening and looking to hone (pun intended) your skills, I'd hop over to the maintenance forum. There's ton of good info over there!

 

[Officer's Match]

I don't think they are necessarily ugly.

 

[Czechmate]

The only disadvantage I see is that they are seriously ugly. Haha.

That's pretty subjective, isn't it?...

Some examples of polished convex edges; I think they look pretty good.

(Police III only in this pic)

 

[19-3ben]

Thanks for the info guys!

If you're new to sharpening and looking to hone (pun intended) your skills, I'd hop over to the maintenance forum. There's ton of good info over there!

I was actually asking because I am very very close to pulling the trigger on a KO-worksharp, and since it would convex my edges, I just wanted to double check before finalizing.

I have been working with stones first to get the basic skills, but frankly, being very pressed for time (two jobs, two dogs, wife, 17month old) the worksharp would cut down my sharpening times and pay for itself with time saved.

 

[19-3ben]

Oh, and I don't think they're ugly at all. I actually love the feel of them too. So let's talk about function.

 

[hermit dave]

With all being equal, a convex edge will be stronger and reduce cutting friction. When I say equal,
I mean the convex "angle" equals the flat edge angle. On the downside, the convex edge would
require a steeper angle of attack to cut and would be harder sharpen with a stone.

A full convex blade grind like the SM III Trail Master and Recon Scout mimics a more acute
edge angle and reduces friction even further. This is why the mentioned knives cut like magic.
The downside is a more fragile edge.

In a nutshell, the smaller the radius of the convex edge, the stronger the edge. The larger the
radius, the "sharper" the edge.

 

[Czechmate]

I like my knives to have the convex grind like the one shown on the right:

When I sharpen they usually end up like the one in the middle though which is okay I guess... :foot:

 

[A.L.]

I like to turn most of my knives to some sort of convex (and I like their looks). Convex forgives freehand sharpening and it's easy to modify with mousepad/paper. Only disadvantage I have had is that sometimes you might accidentally make it bit too steep and bad slicer/whittler. I dunno.

 

[bld522]

That's pretty subjective, isn't it?...

Some examples of polished convex edges; I think they look pretty good.

Few more pics of some ugly polished convex edges just for fun:

 

[DeadboxHero]

The biggest disadvantage? They take more time to sharpen the a regular secondary bevel.

 

[craytab]

Few more pics of some ugly polished convex edges just for fun:

You should be ashamed of that ugly edge and blade

 

[Czechmate]

Man, that's ugly bld22...


:thumbup:

Twins?... I don't have a good pic of my modded RMD besides this one; it's sporting a decent convex edge as well. :thumbup:

 

[Czechmate]

You should be ashamed of that ugly edge and blade

I like this thread a lot. :thumbup:

 

[FW JSB]

They're like any other grind, they have their strengths and weaknesses. There's no miracle knife grind out there that does everything well. Choose the right tool for the job.

 

[19-3ben]

They're like any other grind, they have their strengths and weaknesses. There's no miracle knife grind out there that does everything well. Choose the right tool for the job.

Umm yeah. Hence asking for the disadvantages.

Seems there just aren't many, which is good news to me!!
Now bdl you're just cruel. That's my kinda oogly.

 

[craytab]

Twins?... I don't have a good pic of my modded RMD besides this one; it's sporting a decent convex edge as well. :thumbup:

Make that triplets?

 

[craytab]

The main disadvantage for me to a convex grind is I enjoy the hell out of putting a thin V grind edge on by hand with stones.

 

[bld522]

You should be ashamed of that ugly edge and blade

I wish I could take credit for the finish or the edge. Alas, I can do neither. Credit for those goes to Nathan (norcalblacktail) before he started making his own knives under the Kestrel Knives banner.