• 9point6@lemmy.world
      link
      fedilink
      arrow-up
      19
      ·
      9 days ago

      I find bar more intuitive even if it’s just hPa/1000

      Nearly 7 bar is impressive for any tyres

      • MentalEdge@sopuli.xyz
        link
        fedilink
        arrow-up
        11
        ·
        edit-2
        9 days ago

        Any car tire.

        For road bicycles 7 bar is just “normal”, 8 and above isn’t unheard of.

        A guy once asked if I was crazy when I was pressurizing my hybrid bike to 6 bar, and I just pointed to the sidewall where the rating said 4.5-6.5 bar. The range is wide because the pressure you should use varies depending on what you weigh, and how you want to balance rolling resistance vs comfort.

        And even then the safety margin on bike tires is more than double the max rating, so it’s perfectly safe to go a full bar over if you want.

    • MisterFrog@lemmy.world
      link
      fedilink
      arrow-up
      5
      arrow-down
      1
      ·
      8 days ago

      As much as hPa is legitimate, in English speaking contexts I wish we kept to 10^3 prefixes. (Pa, kPa, MPa, GPa etc).

      Like how we keep to nm, μm, mm, m, km. Mostly.

      Or if one really must, atmospheres. Other units are just more of a pain to convert between, like yeah, it’s metric, so it’s not THAT hard, but just nicer in my opinion if it’s consistent intervals.

      Alas, at least I very rarely need to deal with PSI. Only with valve manufacturers using imperial valve coefficients (Cv values), grumble, grumble. They don’t even include the units usually, which to me is heresy. The units are US gallons/min of water at 60 °F per pressure drop of 1 PSI. Like, US engineers have this really stupid habit of not including units in constants and coefficients in some contexts, drives me up the wall.

      Thanks for being the convenient recipient of this metric engineer’s unit rant.

      • Thorry84@feddit.nl
        link
        fedilink
        arrow-up
        2
        ·
        8 days ago

        As far as I know hPa is the preferred unit for air pressure and is used a lot. Usually referring to the air pressure of the atmosphere.

        Also hectometer is used a lot when talking about land measurements. And we don’t mostly keep to mm and m, in my experience cm is the most used and most useful measurement for every day objects.

        All of the different prefixes are valid and are used. It just depends on what context, which one is the most useful. No reason to stick to the 10^3 units, just use them all.

        • MisterFrog@lemmy.world
          link
          fedilink
          arrow-up
          3
          arrow-down
          1
          ·
          7 days ago

          I should clarify, this is my personal preference, for ease of conversion. I wish we stuck to consistent intervals. They’re all valid, just that I find it very lovely that in industrial/construction we don’t use cm (in Australia)

          But there are so many various pressure units in use, which is a slight inconvenience. Pa, Bar, atm, cm-water, are the ones I’ve come across in actual use so far. (Metric engineering context, RIP US engineers)

          Makes it necessary for me to use a calculator to make sure I’m not messing something up. kPa to mbar: okay *bar/(100 kPa) * 1000 mbar/bar (which I’m now noticing is hPa)

          So in addition to my preference for consistent prefix intervals, let’s also stop using Bar, cm-water, and anything else that’s not Pa. That’d be nice ☺️