Thread: X-stroke or not?

Earlier, I hi-jacked a thread titled "Which strop should I buy?" when I asked Glen (gssixgun) to elaborate on a statement about using an x-stroke versus a straight stroke - basically why would an x-stroke improve an edge and give a better shave over a straight stroke when stroping on a 3" strop. I want to elaborate on the question a little and throw in what I think is part of the answer. For this discussion please assume proper technique.



When using a straight stroke, there is only one vector that describes the movement of the razor across the strop; one that is parallel to the strop. This is represented by the black arrow in the first diagram. In this case, the stroping action will have its effect on the edge in a manner shown by the red arrows - essentially by exerting some force on the edge that is in a direction that is opposite to the vector of the razor's movement.

When using the x-stroke, the vector that describes the movement of the razor is the addition of two vectors - the movement of the razor along the length of the strop (the horizontal black arrow in the second diagram) and the pulling of the razor toward you, perpendicular to the strop, to execute the "x" of the x-stroke (the vertical black arrow in the second diagram). The actual movement of the razor is shown as the addition of these two vectors; the green arrow in the second diagram. Therefore, the force exerted on the edge in this case is such as shown by the red arrows, again in a direction opposite to the vector of the razor's movement.

If the x-stroke (even on a 3" strop) actually improves a shave by improving the edge over that obtained by a straight stroke, I contend that the reason must lie somewhere within this phenomenon (where or how exactly I don't know). A point was brought up about full contact of the edge with the leather; I do not buy this - unless the "imperfection" in the strop (hills, valleys, bumps) runs perfectly parallel to the stroping stroke along the entire length of the strop, I am willing to bet that the entire edge will contact the leather at some point during the stroke.

I do not contend this to be an answer, but I am willing to bet that the answer (if there is one) lie somewhere in this domain. Even in a hobby where YMMV is the norm, we are still operating in the physical world, and this is the physics as I see it. Please point out if and where my reasoning is flawed, and point out my mistakes in logic.

As always, thanks for any and all replies -Gags

Now add a smile to the edge it adds to the theory

Also you had 3 different experienced Senior members say the exact same thing about using a pattern in that same thread

But to keep things clear here is exactly what I posted in response to the idea that a 3 inch strop means no more patterns..

"We can only explain what we know to be truth, most of us that have been doing this a long time know that using a "Pattern" while stropping works..
When you don't learn the patterns, then you serve a self-fulfilling cycle, ie: If you don't learn the patterns well, then not using the Patterns on a 3 inch strop vs Straight up and down stropping makes no difference...

Basically they are your razors, your strops, and your time, so you can do as you want, but please don't assume that there is no difference"

Originally Posted by gssixgun

Now add a smile to the edge

Please - I do not know enough about this process to understand your reference - are you saying that stroping without the x-stroke will cause a smile in the blade? If so, could you please explain how that happens?

Thanks a lot

Yay...vectors!
It is much simple than that, the edge gets full contact with the strop this way, proven over and over again.
of course you can do straight strokes no one says it is wrong etc, but the natural stoke is x-stroke and it gives better result.

I've always looked at it this way: If I have a bent piece of wire that I want to straighten out, I always start at one end, and work my way along it's length to the other end. Too me, it just seems to be the most logical way to accomplish the task.

Originally Posted by Joegags

Please - I do not know enough about this process to understand your reference - are you saying that stroping without the x-stroke will cause a smile in the blade? If so, could you please explain how that happens?

Thanks a lot

No, draw your diagram using a razor with a smiling edge...

Originally Posted by gssixgun

Now add a smile to the edge it adds to the theory

Also you had 3 different experienced Senior members say the exact same thing about using a pattern in that same thread

Thanks for the reply - I understood "what" was said, I just wanted to know "why" one way is better or "how" one way works better. My original question had to do with the "pattern" you spoke of your original post - I get that commiting one's self to learning the pattern will mean that the muscle memory will transfer to stroping on any other strop you use, and I can appreciate and am grateful for useful advise from experienced members (I even attested to this in my first post in the other thread) . I am only trying to understand it underlying reasons behind why something works differently or better than something else. Perhaps a purely academic undertaking with no real regards for the practical world, but that stuff excites me.

thanks again

Originally Posted by gssixgun

No, draw your diagram using a razor with a smiling edge...

This is a thought experiment from someone who knows little so...
That would add a different vector - the goal would be to get every point of the edge of the razor to be parallel to the movement of the blade along the strop as you continue the stroke, right? So on a 3" strop you would not need a true x-stroke, but more of a horizontal "roll" of the wrist (bad word, but I can't think of a proper one - more like the wrist starts behind the blade at the beginning of the stroke, then accelerates a little faster than the blade so that the wrist is a little in front of the blade at the end of the stroke)

Does this sound right?

Lately I've seen lots of posts encouraging the purchase of 3" strops so the user won't need to learn the X-stroke. Strange advice; if this community was about short cuts then we'd never have taken up straights.

Go ahead and buy the widest strop you can find--our merchants will benefit from sales of a premium item--and make sure all your hones are 3" wide as well--the economy will grow--but you'll still be cheating yourself by not learning this simple extra degree of motion in your stropping and honing strokes. The OP is correct that an X-stroke on the strop gives a better mix and match between any of the strop's and blade's individual irregularities, but incorrect (in my opinion) that such mixing is too subtle to matter. I think of a lawn where I lived and mowed for about five years. I always mowed the same pattern, never varied, and eventually wore ruts for the mower wheels. Besides being an appalling metaphor for my life at the time, it was a lasting example of how materials can acquire a memory of how they've been used.

Imagine a small burr in the center of your blade. If you never vary your strop stroke, you'll eventually erode the strop surface where the burr is. With an X-stroke, you'll distribute that wear more evenly over the leather. In either case, of course, you should go to the hones and repair the burr. At the scale of razor edges, this is an extreme example. They are microscopic creations, and their work is done at the microscopic scale. For that reason, I believe that we should take every proper care to even out microscopic sources of wear and tear, and for me that means X-strokes on every strop, no matter its width.

The necessity of X-strokes (and rolling X-strokes, which the OP approaches describing) for smiling edges manifests at a more macro level. Even if you're starting with a new, nonsmiling blade, you may want to cultivate a rolling X-stroke on the hones, since it's so much better to err towards honing in a smile than towards honing in a frown.

In short, in my opinion, there is no good reason at all to avoid learning an X-stroke.

This response isn't just to this thread, but to all the posts I've been seeing that treat X-strokes as some exotic challenge that should be corrected not by better technique but by wider hardware.

/

Vector Victor.....I use 3 inch strops and hones and use an x stroke. Can't see the downside really.