Strava (not Garmin after all) broke climbpro

I’m not sure it’s a compounding data error just because of a lot of points if that’s what you mean. I think it might be missing data points due to a calculation error as the distance between points approaches 0. The distance isn’t constant, there are some data points as close as a metre apart and I think that might be where the errors are creeping in. 
the error tends to jump at certain points, rather than be linear. 

I too had problems doing "We Ride Flandres" and Climb Pro, it was way off, and to no use as such. Had the course from the organizers web page unto Strava and then synced with Garmin Connect.  Ride seen here :  www.strava.com/.../8813294883

It appear that the points closer together are likely causing bigger issues. There are 190 points that are less than 1 meter apart. A precision issue would not have to generate a linear displacement depending on how values are rounded or trimmed. Some values could under report the distance and some values could over report the distance. The displacement is the accumulation of the under and over values.

With the data points I can now go and calculate the distance between them and play around with removing points that are close together and see how the distance changes.

Yup I agree that the points being so close might well cause issues . I saw errors when I imported the data into excel and used the points to calculate the distance. 

I think one way of isolating it would be tweaking the course data loaded via the API. I have access so will have a crack if I find the time. 

I have a spreadsheet set up to do distance calculations from the course Lat/long data. Let me run the course data through it and see if I get a similar total distance value.

Hello. I have also experienced lag on ClimbPro. And have tried to create several routes on Strave which I have transferred to GC, and then downloaded a GPX file from Strave and a GPX File from GC after transfer in API. I can't get the error. I tried the Flanders GPX route that is in this thread, and then I get the error. But when I force Strave to recalculate it, by editing the endpoint and saving it as a new route, syncs it over. Then the routes are in perfect sync again.
EDIT: I'll also did a test with RwGPS, and the route are in sync there too.

So then I wonder if Garmin this week has fixed this now? And that the video of GPLama has had an effect?
And a great thanks to Jeff -- jgforrest  for "proof" of this error.

 

Digging into the Tour of Flanders gpx files I can see where the offset is happening, its a step rather than gradual and it happens noticeably at 20.1km, at 54.3km, and again at various points, but I can't see any smoking gun reason why. I thought it might have been errors from distance between points approaching 0 but that happens fairly regularly and the Strava data even has duplicate points that don't correlate with the offset.

Try this:

• Make a copy the Tour the Flanders route on Strava.
• Star it, and download both GPX files. You will see the offset in the GPS Visualizer.
• Then edit the Copy of Flanders route, by changing the endpoint, route typer etc,
• Unstar it, and restar it to resync the route to GC.
• Download the GPX or FIT files again. And compare them with GPS Visualizer.
  
  In my case the route is in sync. I'm hoping that Garmin have fix the bug this week?
  Maybe this happen because the route is catched in the API?
  All my route that have been sync the last 2-3 years from Strave or RwGPS have had this lag. If it's fix, it moust have been done lately.
  
  EDIT: I tryied this againg today, and the LAG is back on the Flanders route. Stranges.
  EDIT: Other new routes, that is created fresh today are in perfect sync.