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Excessive power peaks

Posted: Sun Nov 12, 2017 7:29 pm
by bfermar
They continue to appear excessive peaks of power on negative slopes, which do not correspond to the strength in the pedals. In those cases it always shows wind readings that seem excessive to me, as it appears in the catches. Could it be a problem with the wind sensor hardware?
Regards

Re: Excessive power peaks

Posted: Mon Nov 13, 2017 7:04 am
by bfermar
All these problems make me think that something is not working well. The innumerable calibrations have not solved it (even one of the profiles that you returned me kindly, corrected, made the situation even worse) the firmware is updated .... I am very disappointed with these problems. I would like to send it to you for your review ? Could you provide me with a shipping address? I live in Spain
Regards

Re: Excessive power peaks

Posted: Mon Nov 13, 2017 8:22 am
by Velocomp
Nothing is wrong with your PP sensors, and your unit appears to be properly calibrated, except that your Crr is a bit high. A corrected profile is attached.

Your CdA suggests you are riding in the drops; is this correct?

When pedaling on downhills, the PP is VERY sensitive to rider position. Any variation from normal ride position, (for example, going in to a tuck to pick up more speed on the downhill) will be reported by PP as higher watts.

I agree with you that excessively high wind speeds could also cause a problem, but this is a long course, and overall your wind speed is close to your bike speed. I don't think your unit is calibrated improperly.

Re: Excessive power peaks

Posted: Mon Nov 13, 2017 2:44 pm
by bfermar
Most of the time I go in the hoods. What value of Cda would be appropriate? It is currently at 0.310. I measure 1,72 cm and weight 70 kg.
I use the Crr value corresponding to the "Tire grade: Utility" Should it be lower?
Could you send me the corrected profile again? I do not see it in the post
Thank you very much for the excellent customer service

Re: Excessive power peaks

Posted: Mon Nov 13, 2017 2:52 pm
by bfermar
What I do not understand why the Powerpod increases watts when switching from hoods to drops ... Should not the watts decrease as the position is more aerodynamic?

When you send me this last profile corrected in the values of Cda Crr I will use those same values in the profile for the second bike

I wait your response

Regards

Re: Excessive power peaks

Posted: Mon Nov 13, 2017 6:35 pm
by Velocomp
bfermar wrote:What I do not understand why the Powerpod increases watts when switching from hoods to drops ... Should not the watts decrease as the position is more aerodynamic?

When you send me this last profile corrected in the values of Cda Crr I will use those same values in the profile for the second bike

I wait your response

Regards
The more aerodynamic you are, the faster you will go for a given amount of applied power. But PP doesn't know you're more aerodynamic; it only knows you ride faster when you move from the hoods to the drops. Where does that extra speed come from? PP believes you haven't changed ride positions, so it attributes the extra speed to more power.

I think your current profile is OK.

Re: Excessive power peaks

Posted: Tue Nov 14, 2017 7:43 am
by bfermar
Ok, understood, but what values of Cda should I use?
I lowered it somewhat looking for better response on the negative slopes, but my normal position is on the hoods.
It seems that decreasing the value of Cda does not help in the downs, by the way of working of the PP
0,340 in hoods is ok? It is the value Isaac assigns by default for my height and my weight in hoods

Re: Excessive power peaks

Posted: Tue Nov 14, 2017 2:18 pm
by Velocomp
Use the value of CdA that is determined by the "Device/Device Setup" wizard.