• fiah
      link
      fedilink
      English
      arrow-up
      3
      ·
      1 year ago

      that’s a chain with an extra roller

    • sudo@lemmy.fmhy.ml
      link
      fedilink
      English
      arrow-up
      3
      ·
      1 year ago

      It appears it’s just an additional gear to keep the chain from hanging as low and loose as traditional chains to help prevent things, like pant legs, from getting caught in it.