Calibration problem with an out-back ride.

[Rob_B]

I only had the original mount that I swapped between 2 bikes.
But now I have received my 2nd mount and did a calibration ride.

The first 8 minutes power was way to high but after that settled on normal numbers.
About 30 minutes in to the ride I did a 14 minute out-back segment. And split that part from the ride file.

But when I use this file with Analyze-Check Calibration and than try to send the profile to the PP I get an error.
It looks like Isaac makes changes that the PP can't work with. I get a negative friction number. (would be nice if that was possible )

isaac_error1.jpg (54 KiB) Viewed 5168 times

Isaac changes the tilt from -0.5 to +0.9% That is less than 1 degree on the mount I think.
But at the start of the full ride Isaac shows a 5% slope but the road is almost flat here.

And I see an other problem when I try to repair the complete file for "Bad Tilt Cal" (atleast I think that is what "Bad Tilt Cal" is used for)
When I use this the high power at the start of the ride is gone but the average power over the whole ride is wrong. It drops to only 19w.

Am I doing something wrong or is it some how a bad file?

[Velocomp]

Honestly, your ride files look fine and I would leave things alone.

[Rob_B]

Yes, the files look fine. Atleast after the first 8 minutes.
Is it possible to correct the first 8 minutes with Isaac?

And will the PP now remember the corrections that it made during the first 8 minutes on this ride when I start a new ride in the next days?
Or will it start with the loaded profile and give high numbers again?

[MarkS]

Rob_B - This is what I do for each ride.

Even though my PP always goes on in exactly the same position for each ride, 9 times out of 10 mine recalibrates for the first 6 to 8 minutes of my rides. I have just accepted that is part of using the PP and for me the first 10 to 15 minutes of each ride are part of the warm up stage of the ride so the first 6 to 8 minutes is not critical data.

Then when get home I use Issac to correct the power data. After uploading the ride in to Issac I start with Analyze: Analyze Newton Settings and change the Starting Elevation to the correct start elevation which I know for my home.
Next I select Analyze: Analyze Route. I make sure Ride Ended Where It Began is selected, Wind Changed is selected and Ride Has Out & Back is deselected. After clicking Accept the power data is updated and the first 6 to 8 minutes should show more meaningful data. All my rides start and finish in the same place, usually home.

I use Golden Cheetah to analyze my rides. After uploading my Garmin FIT file to GC I copy the first 6 to 8 minutes of the corrected Issac PP power data from the CSV file created by Issac in to GC so that I have more meaningful power data for that period to use in GC.

[albafar]

@ MarkS . This is interesting to me - not so much the calibration issue with almost every ride which I luckily don't experience. But the fact that you use Isaac as well as GC and GC. What parts is it you use GC and GC for on which Isaac apparently cannot deliver - what specific analyses do you do in GC??

[MarkS]

@albafar - GC is a comprehensive training monitoring package similar to TrainingPeaks. Basically it stores all your rides so that you can keep track of your training performance by ride and also over all rides or any selected period. The main analysis revolves around a Performance Management Chart which shows over a period the key training indicators and how they are changing. Issac only shows the data for each ride and doesn't have any cumulative tracking functionality.

There are loads of training indicators you can set up in GC. So if you are interested in a structured training plan it is useful software to have.

GC is open source so you have nothing to lose downloading a copy and giving it a try.

[Rob_B]

@Marks. Thanks. I had found that you can use "analize route" to fix the first minutes of a ride somewhere on this forum (through Google)
I was going to post it after testing it today. You beat me to it.
On today's ride the power was very low during the first minutes. Where it was high two days ago. Without taking the PP of the bike.
The low numbers aren't that bad. At least these don't mess up the power charts on Strava.

But with the changing number during the first minutes I don't what to use the auto upload to Strava through Garmin Connect.

I have to look at Golden Cheetah. I already use it for my indoor training but haven't tried it with my outdoor rides and the PP.