• Posts
  • RSS
  • ◂◂RSS
  • Contact

  • Planetary gearing taken to excess

    August 21st, 2009
    bikes, transport
    The schlumph mountain drive bottom bracket with planetary gears looks pretty cool. It is foot actuated and allows a reduction of 2.5. I was curious what sort of gears it would give my bike so I calculated:
    front gear rear gear gear inches
    1 1 18.6
    1 2 25.5
    1 3 34.6
    2 1 44.6
    2 2 61.1
    2 3 83.1
    No wasted gears, a nice shifting pattern with only one double shift, as low a gear as I could want for a really steep hill or a really heavy trailer. A total range of 501%, which is almost as good as a rolholff's 526%. The schlumpf is rated for use with coaster brakes, and my SRAM T3 is tough enough for the schlumpf. But how to justify $.5K for a new bottom bracket?

    For reference, my current gearing is based on approximately 28 inch wheels (622mm rims, largeish tires), a 48 tooth front cog, a 22 tooth rear cog, and a SRAM T3 hub that offers 1st, 2nd, and 3rd at 73%, 100%, and 176%.

    Comment via: facebook

    Recent posts on blogs I like:

    How much time and money does an additional child take?

    Some things scale, others don't. The post How much time and money does an additional child take? appeared first on Otherwise.

    via Otherwise March 19, 2023

    What does Bing Chat tell us about AI risk?

    Early signs of catastrophic risk? Yes and no.

    via Cold Takes February 28, 2023

    Why Neighborhoods Should Have Speed Bumps

    I have several reasons I think why neighborhoods should have speed bumps. First, speed bumps are very useful to stop cars from hitting people in the streets. Second, when construction workers installed speed bumps on the street in front of our house it was v…

    via Lily Wise's Blog Posts February 27, 2023

    more     (via openring)


  • Posts
  • RSS
  • ◂◂RSS
  • Contact