This started happening a week or two ago, using Garmin 235. On Garmin Connect web and mobile, the overall reported pace average is correct, and the average pace horizontal line is in the right place, but the by-moment pace values plotted appear to be double the pace (faster) than actual pace. On web, in the zoom popup for pace, it is easiest to see.
Here are two screenshots.
First from a run I made 1/9 with my 235 using its built-in heart rate monitor:
This looks fine except for the obviously wrong heart rate data. This is around the time I gave up using the 235 with the built-in HR monitor.
Now here is a more recent run, recorded with my 235 and using an external Scoche HR monitor, with the 235's internal HR monitor disabled:
Elevation and heart rate are correct. The average pace line is also correct, but as you can see it does not match the instantaneous pace data, which is twice as fast as my actual pace.
Notice: the run cadence is also double what it should be! And also (not shown in screenshot) my average stride length is half of what it should be.
Here is my theory: either (1) the 235 is combining its own foot pod data with the Scoche footpod data (didn't know before that the Scoche watch emitted this data, but am noticing that the 235 links to it at the same time it links to the Scoche HR), effectively doubling every step I make, or (2) the 235 is using only the Schche footpod data, which is emitting twice as many footsteps as it should. Garmin Connect Web might be computing average pace by dividing total distance by total run time (correct), but computing the instantaneous pace by multiplying steps per minute by the stride length derived from only a single footpod data stream, causing the resulting pace to be twice what it should be.
Any other ideas would be appreciated! I can't seem to find a way to disable the 235's own footpod data in the watch's config.
