Significant change suggested after "normal" ride

[munkster]

I went for a fairly easy "recovery" ride today and when I got back and downloaded a bunch of recent rides this most recent one resulted in the suggestion of a "significant" profile change when I clicked (purely out of curiosity to be honest) on "Check Calibration". It suggests that my average power should 16.2W rather than 136.8W - now while I was taking it easy and coasting more than normal, this does seem pretty drastic!

Isaac file attached.

Any ideas? Thanks.

[Rob_B]

The check calibration function only works on out and back rides.
You have to start and end in the same place and follow the same route out and back.

Or you have to do a part of your ride as an out and back and split that part from your ride file. Then use that part to check calibration.

[munkster]

I knew it had to be an out and back ride but I didn't realise the two legs had to be identical, that may be where it's spat its dummy out then, although well over half of the ride is out and back on the same road. I am sure I did a "Check Calibration" on the exact same route a while back and it didn't have nearly the same extreme outcome.

[Rob_B]

I have read on these forums that it is better to do a short out and back ride. I try to keep it at a total of around 8 to 10 minutes.
That is enough to get useful info and not too long to risk changes in wind force or direction.

When I do an out and back I do it during a longer ride. And stop at the start and end to make it easier to find it in the ride file when I get home.

[Rob_B]

When I look at your ride file I see that the cadence is missing after 8 minutes. Not sure if that is causing the problems when checking the calibration.

[munkster]

That's odd - the cadence stats are there for the entire ride on the uploaded Strava ride, that may well be a contributing reason though, thanks for taking the time to look at it.