Comment on Wednesday SOTD Thread - October 9th, 2024 (#486)
djundjila@sub.wetshaving.social 10 months agoI think it is all about geometry.
that would make a lot of sense
Sadly, my River Razors 6/8 has a bevel angle of 19.2 degrees.
Does that mean that it’s not a favourite?
gcgallant@sub.wetshaving.social 10 months ago
Sadly, yes. I’ve known for a long time that typical razor bevel angles fall between 15 and 20 degrees. I tinkered with this, myself, a couple of years ago. I reduced the spine width on my Gold Dollar to change the sharpened bevel angle from just over 20 degrees to 18 degrees. Took a long time. The feel of the razor improved considerably.
djundjila@sub.wetshaving.social 10 months ago
That’s a bummer.
I don’t want to imagine how much time and effort it took to whittle down the spine enough to make a meaningful change in bevel angle 😅 .
Btw, I now want to measure my 17. I have a feeling it may have a blunter angle than my other razors, but it still shaves great. I need to double check my assumptions here.
gcgallant@sub.wetshaving.social 10 months ago
Btw, I determine the bevel angle by just calculating the sharpening angle and doubling it. On all the razors I’ve seen, the sharpening angle falls well within the range where the small angle approximation for sine works. Typically, I just do the trig in my head.
Once I started paying attention to sharpening geometry, I started to realize why I like certain razors so much. I would be very interested in your experience on this as well. I’ve realized the ways in which I adapt to razors with wider bevel angles and this tips me off to actually measure them.
djundjila@sub.wetshaving.social 10 months ago
I’m not sure I follow. I’d have just measured the spine thickness t at the place of hone wear, and the width b from edge to spine hone wear and computed the bevel angle as α= 2 arc sin(b/(2w)), just as the central angle of an isosceles triangle . Is the sharpening angle β = α/2? in that case, I agree that β ≈ sin(β), certainly at the precision I’ll have measuring t, and b.