Spoke Tension Calculator

I use this spreadsheet in the last step of a wheel build.  It converts spoke tension measurements from a Park Spoke Tension Meter into kilograms force (Kgf) and checks for tensions that are outside specified limits in absolute tension and variance in tension between spokes.  The tension limits can be edited.  The defaults are limits suggestion in the book The Art of Wheelbuilding by Gerd Schraner.  In my wheels (all 406), I make a few passes with the tension meter and spoke wrench to bring all spokes within the absolute tension limits and minimize the variance between spokes as much as possible.   But I give up long before all the variance numbers are within limits (there’s still plenty of red in the spreadsheet).  It’s possible that it’s easier to achieve these tolerances on a bigger wheel but I’ve never tried it.  Or that my calculations are off.  But I can say that I’ve never had a problem with a wheel built this way (I’ve re-trued maybe twice to correct very minor wobbles) so I’ve learned not to sweat it.

5 thoughts on “Spoke Tension Calculator

  1. Pingback: Wheelbuilding | A Seasonal Commute

  2. paul needham

    Hi there

    Love the spreadsheet , I think the tension is also related to spoke size ?

    For plain spokes in SS I am using 14g [ 2mm ] will this table work ?

    regards Paul

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    1. Kurt Post author

      Hi Paul,
      I’ll have to take another look at the Art of Wheelbuilding reference I based this on, but I don’t think it considered spoke diameter for the tension recommendations. Of course there may be other, perhaps better limits out there, the spreadsheet lets you enter those if you don’t want the defaults. That said, 2mm spokes are what I’ve been using with these limits, with good results. FWIW over time I have gotten better with evening out the tensions using this spreadsheet, now I can usually get rid of most if not all of the red (indicating outside the limits). There does appear to be a bit of an “art” to this process…
      kurt

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      1. paul needham

        Kurt

        Thanks for your prompt reply.
        I build Python trikes and want to use SA hub brakes , however they come just as component parts and so need lacing into rims before they can be used.
        https://atomiczombie.com/forum/threads/my-life-with-python-trikes-mk1-mk1-5-mk2.33/

        Few wheel builders use 406 wheels so I was quite excited when I found your page.

        I also tour , mainly Holland [ 5th time this year ] and this year trying to wean myself off trailer towing and carrying all my gear on the trike.

        regards Paul

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  3. Kurt Post author

    Good luck Paul, I think you’ll find lacing your own wheels is quite doable and even enjoyable. I’ve had good luck with the SA drum hubs in the past.

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