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Very low power

Posted: Sat Jan 19, 2019 10:47 pm
by offpiste.reese
Using the PP on my fat bike in the snow again. I had really low power readings for the entire ride and I'm not sure why. It was a pretty tough ride, I would guess my NP would've been 180 or so, just from feel. I got a NP of 79. It was heavy snow and I was breaking trail the first lap through. Any ideas on the issue would be appreciated. The last ride I took in the snow I got power readings I thought were pretty good.

Re: Very low power

Posted: Mon Jan 21, 2019 5:39 pm
by offpiste.reese
Another ride today with the same results, very low power readings. I was really pushing today. No thoughts on why it's reading low? I had 1 good ride in the snow, but the last 2 have been way off.

Re: Very low power

Posted: Mon Jan 21, 2019 6:44 pm
by Velocomp
offpiste.reese wrote: Mon Jan 21, 2019 5:39 pm Another ride today with the same results, very low power readings. I was really pushing today. No thoughts on why it's reading low? I had 1 good ride in the snow, but the last 2 have been way off.
Your ride file shows that your average bike speed was about 5 mph...that is a fast walking speed.

I think something is wrong with your speed sensor.

Re: Very low power

Posted: Mon Jan 21, 2019 8:28 pm
by offpiste.reese
No, it was a bit below 5 mph. I'm riding on snow. That I pack myself. It's very slow. I actually XC skied the same course a bit faster. So there's nothing wrong with my speed sensor.

Re: Very low power

Posted: Mon Jan 21, 2019 8:45 pm
by offpiste.reese
https://connect.garmin.com/modern/activity/3319535029

Speed on there is a little low, I forgot to stop the Garmin when I stopped.

Re: Very low power

Posted: Tue Jan 22, 2019 8:01 am
by Velocomp
What's going on is that snow is causing really high rolling resistance...much higher than what you would find on any road or trail.

I've adjusted your Crr to 0.05--a value about 5x higher than your current setting. This gives an NP of 179W.

Load the attached profile into your unit and you should get better numbers.