To add to a couple of similarly-themed but different threads, I thought I’d add my recent odd experience.
I went on a 4 hour ride on Sunday. Afterwards, when uploading to TrainingPeaks, it said that average watts were 174 and Kj were 2682. Which can’t be right, as 174 x 4 x 3.6 (the standard watts to kj calculation) is 2505.
Then it gets weird. I deleted the first 5 seconds, and only the first 5 seconds, of the workout data. The Kj stayed the same at 2682, NP the same, but the average watts suddenly changed to 185. Which x 4 x 3.6 = 2664; so basically matching. See screenshots below.
God knows what’s going on. I’ve submitted a help ticket to Wahoo, because it seems that there’s a possibility it could be regularly giving me understated average watts.