What the fuss with new razors over the old ones?

Discussion started by The Kman, Mar 15, 2017.

  1. The Kman

    The Kman Member

    Well, you learn something new every day! I still reckon brass isn't a great choice of material, but looked up the Coefficient of Linear Thermal Expansion for brass versus Austenetic Stainless Steels and it turns out they're very similar, 18-19 versus 16-18 respectively. So arguably, brass has better casting and machining properties given it's lower hardness.

    @Korbz: May I ask what razor you have pictured there?

    A Rockwell 6S arrive on Friday and I used it on R2 for the first shave yesterday... very interesting outcomes. I'm comparing it to the most effective configuration of the AS-D2 I've tried so far which is using a Feather blade with a single 0.1mm shim under it.


    Firstly, it's worth noting that the 'aggressiveness' and 'effectiveness'of the R2 plate compares pretty well to the Feather with a shim. The major difference is tolerance for errors and pressure. The Feather AS-D2 is reasonably forgiving, but the 6S allows me to move around much faster without concern for nicks or irritation.

    You can see from the image the very different head designs of the two. The Feather is very similar to the old tech I have, where the 6S more closely resembles several of the newer style designs with a larger relief behind the blade. In the 6s image I've highlighted the 'flat' pre-edge and post-edge reliefs, and also the 'effective' reliefs when you consider that the 6S has a slight angle on the wide bar.

    The presented angle of the Feather is slightly shallower, but I think the relief behind the blade on the 6S, rather than in front of the blade like the Feather, goes a long way to ensuring addition pressure doesn't make the presented angle steeper. On the contrary, I think added pressure on the 6S would tend to decrease the presented angle where on the Feather it wold increase the presented angle due to the way the skin would expand into the reliefs.

    Another interesting note is the support point for the blades on each. The Feather has a very dead acoustic presence, while the 6S really sings which I believe can be attributed to the support point. The 6S has it's support way back behind the edge of the cap, where the Feather has it's support very close to the edge almost directly below the edge of the cap. If you look carefully you can see where the blade and the shim are being pinched under the cap.

    So, it appears to the me that the Feather is a fairly traditional design with a well supported edge, but lots of pre-edge relief. While the 6S appears to be a more modern design with a fatter bar and very narrow pre-edge relief which may be guiding the skin into the edge with less concern for pressure.

    For the sake of reducing the number of variables I've use the same blade, same prep and same number/direction of passes. Weight is similar and I think static presented blade angle differences are negligible.

    Any thoughts?
  2. Sxot

    Sxot Member

    My only thought is you have looked into this WAY further than I have ever considered. The support point of 6S being further back would also lead to more blade chatter and therefore be undersiable?
  3. RazorPlay

    RazorPlay Member

    Not necessarily - this reminds me of the different between a rigid shavette and a full hollow straight. The consensus seems to be that the flex of the full hollow gives a smoother, less harsh shave. I imagine the same would be the case for DEs, provided the flex in the blade wasn't too soft, leading to chatter. In other words, the ideal would be enough flex to run over (rather than through) the skin, without having so much flex that the blade chatters. I can see how this would be a difficult balance to achieve and would be very specific to someone's face / technique. We know that in the hands and on the face of some, the exposure of an R41 gives a perfect shave while for others, their face / technique results in lots of damage with the same design.
    Snooze and silver like this.
  4. nav1

    nav1 Member

    I would think the same and yet the 6s holds the blade so tightly, there's practically no blade chatter.
    silver likes this.
  5. Snooze

    Snooze Active Member 2017 Sabbatical Fail

    Maybe why adjustable are so popular? Can change some aspect of blade gap / aggressiveness / whatever to achieve that individual balance?
  6. The Kman

    The Kman Member

    The amount of force required to deflect the blade on the 6s is quite high, doesn't seem reasonable that your skin could do this. To be honest, if you're applying enough force to deflect the blade on a shavette or hollow straight, I think you're doing it wrong! Could just be me though?

    It seems far more likely to me that the different designs effect how the skin moves around the edge, rather than the other way around. I don't know anything about how straights are ground or honed, and I don't imagine my skills with wood working tools translate, by I imagine even the most hollow grind would still be extremely rigid compared to your face.
    silver likes this.

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