Hi,
For the first time since I purchased my 6X in september I decided to give PacePro a try (that was one of the features I added to reasons for buying, better late than never...).
I have a course, created from a run I regularly do, that is about 10.3km. Opened the course and started to create the PacePro profile. Decided to go for a 6:00 min/km pace to have time to really see how it works and switch between screens:
Synced the watch and used the trail running app (to not interfere with VO2). Already at the first km mark I realized something was wrong. According to the auto lap I had a pace more than 10s faster than the pace showed by the pace pro screen. Continued and for km 2 and 3 it was the same, 5-10s faster than PacePro pace. At km 4 I payed more attention to the distance remaining and realized that it isn't in line with the activity distance.
First thought was that it used the km markers from the course and tried to calculate distance left using current position. For the rest of the run I checked both lap pace (according to the trail running app) and compared with PacePro lap pace and where respective notified a km was done. In the end, when PacePro said the course was done, I was 38s behind (total time) according to PacePro but according to the activity summary I had a pace of 5:52.
The course is 10.31km, the activity distance was 10.27km.
I compared the km markers of the activity, the course and where PacePro said I passed 5km and 8km. For 5km it looks like this:
Course map (red circle is 5km according to PacePro):
Activity map:
It is obvious that the PacePro feature use a different algorithm for distance compared to the activity and that PacePro lacks the accuracy required to use it as a guide during a race. 38 seconds behind a 6:00 pace for 10.27km is a pace of 6:04 which compared to 5:52 is a difference that will have an impact.
Is this how it works, specific to the trail running app or something that happens from time to time?
As a note I can say that my distance calculations, and pace is mostly within reasonable limits.
Best regards,
Tobias
