Timing discrepancy - Zwift Power vs Strava for Glasgow Crit

I rode the Zwift Games Stage 4 at 12-March 09:00hrs (UK time) Cat D and recorded a “race” time of 26.05 in the zwift companion app and in zwift power. When I look at my strava account activity for the race and drag the cursor to the end of the 5th lap crit segment - which equates to the 15.2 km event distance I find the blue tracking blob is in the proximity of the end of the champions sprint - the equivalent time showing is circa 25.29. Scrolling the blue blob to match a time of 26.05 takes me around a few more bends and up to a distance of c15.6km with the blue blob certainly no longer in the vicinity of the champion’s sprint finish line (or even on the same straight).

Does anyone have any idea as to why the discrepancy or is this purely within the tolerance / error limits of an automatic file transfer from Zwift to Strava.

Besides wanting to understand - my ulterior motive is to try and finish within 10% on time of the top 5 in the overall GC category and hence just want to confirm that my timing has not been mis-stated in Zwiftpower. Please advise as to whether this is the appropriate place to raise or should I go to the race organizer?
Many thanks - GW


This is just a question of when the timer starts. The race time on the companion app and zwiftpower starts when the countdown hits 0. Your time on Strava starts when the fit file starts and that depends on the course. On Glasgow crit there seems to be around 30 seconds to get from the start box and over to the point, where the fit file starts recording, as i have around the same difference in mine. On other courses that may only be 5 seconds.

You can see it on the screenshot of the course where it only start recording when you enter the course properly missing the whole lead in section where you cross the road above


Joakim - many thanks for your response - that’s cleared it up for me.
I’ve had a look at a couple of the recon rides on you tube for this route and it is as you say. The race timer starts when the gun goes out of the pen, the elapsed time starts at the start of the lead in which for the Glasgow crit is the start of the champion’s sprint, hence there is the gap (depending on your speed) of circa 30 secs of “pre” lead time and distance which isn’t recorded in the fit file that goes to Strava. I would have thought that the lead in would start at the pens but that isn’t the case. Not intuitive but it is what it is. I’ll need to look elsewhere (probably repeating stage 3 to try and improve my GC standing time).

Congrats on your Big Spin race podium afternoon. :+1:

1 Like