# Easy way to edit .gpx file?

For a few weeks my powermeter was giving me issues (powertap p1 pedals). I eventually found out my wahoo was calculating my crank length as 110mm instead of 172.5mm, so my power was reading as about 110/172.5 = ~64% of what it should of (aka mega low). Does anyone know a way to easily edit the gpx files so that I can fix my TSS graph on trainer road? Or have an alternative just so that I can have my long term totals looking as expected?

If you can dig up a .fit file for the ride you could use https://www.fitfiletools.com/

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Wow this is perfect! Seems pretty straightforward to do whatever % increase I need. Thanks!

You could manually put in custom TSS values. The corrected TSS should be 2.45x the computed TSS.

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Ah that might be easier so I don’t have to reupload the files to here or strava. Just curious how you calculated the 2.45x multiplier?

If your power is reading 110/172.5 (0.64) of what it should, then what it should read is 1/0.64 of what it did read (~1.57). Normalized Power is proportional to measured power, so corrected NP = 1.57 x measured NP. TSS is proportional to NP squared, so corrected TSS = (1.57)^2 * measured TSS. 1.57^2 ~= 2.45.

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