Forerunner 965 – Ultrac Mode Distance Inaccuracy During 175 km Ultra Trail

Subject: Forerunner 965 – Ultrac Mode - Distance Inaccuracy During 175 km Ultra Trail

Hi everyone,

Last weekend I completed a 175 km Ultra Trail race over 42 hours, using my Forerunner 965 in Ultrac mode. Unfortunately, the recorded activity shows a total distance of 221 km—significantly more than the actual race distance.

This discrepancy also led to some segments being logged at unrealistically high speeds, resulting in inflated pace data and incorrect speed records.

I’d like to ask:
Is there a way to correct the .fit file using the official .gpx file of the race track to reflect the accurate distance and pacing?

Any guidance or tools you can recommend would be greatly appreciated.

Thank you,
Alessandro

0 FredGolightly 4 days ago

How is the gpx trace compared to the actual course, visually?

0 ACENTRONE 4 days ago in reply to FredGolightly

The .fit file of my activity shows a couple of sections where where the trace goes completely off from the gpx trace of the course. In these sections that look inaccurate, one can see a small appendix that looks like a straight line that goes back and forth and that deviates from the original course. Thank you for asking.

0 FredGolightly 4 days ago in reply to ACENTRONE

There may be a tool in this list www.dcrainmaker.com/tools or perhaps someone who can help more directly, I'm not surre of the .fit format for editing