problems revealing power downhill

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FedeSp
Posts: 23
Joined: Sun Jul 30, 2017 2:51 pm

problems revealing power downhill

Post by FedeSp »

hello, I had to replace my powerpod for a problem with the USB port. Now I have a problem, I hope you can fix it ... practically when I pedal downhill it signals over 500 watts of power. How is it possible? What's the reason?

I am attaching the calibration and the last exit where you can clearly see the problem.

Greetings see you soon.
Attachments
iBike_03_13_2018_0935_4_km_CalRide.ibr
(40.62 KiB) Downloaded 176 times
iBike_11_16_2017_2310_61_km.ibr
(552.85 KiB) Downloaded 166 times
Velocomp
Velocomp CEO
Posts: 7793
Joined: Fri Jan 11, 2008 8:43 am

Re: problems revealing power downhill

Post by Velocomp »

This has nothing to do with your replacement PowerPod

What I suspect is that, when you descended the second hill, where watts are high, you went into a more aero position.

Your CdA aero setting is .36. When you are more aero your CdA drops, and you go faster. PP does not know you change position, and it attributes your higher speed to more watts. Thus, high watts in a tuck

When I adjusted your CdA to 0.3, your downhill watts returned to normal.

When you descend, if you don't pedal PP will be fine. If you pedal but maintain your normal position, your PP will be fine. But if you pedal on a downhill and go into a more aero position, PP will read high.

Ride file with CdA = 0.3 is attached.
Attachments
FedeSP_11_16_2017_2310_61_km.ibr
(575.92 KiB) Downloaded 177 times
John Hamann
FedeSp
Posts: 23
Joined: Sun Jul 30, 2017 2:51 pm

Re: problems revealing power downhill

Post by FedeSp »

thanks jhon for the timely reply. I do not say that I have any problems with the Powerpod but I think it is not correctly positioned. say that for him the slope is -4 indeed that -7 could be there this error if placed badly? I hope I explained myself. I'm waiting for news. Federico
Velocomp
Velocomp CEO
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Joined: Fri Jan 11, 2008 8:43 am

Re: problems revealing power downhill

Post by Velocomp »

Please post an image showing how your PowerPod is mounted.
John Hamann
FedeSp
Posts: 23
Joined: Sun Jul 30, 2017 2:51 pm

Re: problems revealing power downhill

Post by FedeSp »

1524737907711540425623.jpg
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15247379724051667716638.jpg (67.09 KiB) Viewed 5579 times
could it be that it is still some degree positioned upward? let me know if the photos are ok. I look forward to hearing from you.


Federico.
Velocomp
Velocomp CEO
Posts: 7793
Joined: Fri Jan 11, 2008 8:43 am

Re: problems revealing power downhill

Post by Velocomp »

Is your combo mount made from plastic? Who makes the mount? How is it attached to your bike?

Please post images of your mount, without the Garmin attached. I would like to get a precise idea of how it connects to the bike.
John Hamann
FedeSp
Posts: 23
Joined: Sun Jul 30, 2017 2:51 pm

Re: problems revealing power downhill

Post by FedeSp »

15247733531933069423.jpg
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15247734200361527824966.jpg (90.52 KiB) Viewed 5564 times
hi john the hard plastic thank you support and is firmly fixed to the handlebar to prevent it from moving. the lower part is made of metal and the screw is as tight as possible for the same reason. your Italian colleague some time ago told me to put the writing parallel to the ground. I noticed with a bubble that the writing is tending upwards, this could offset the slope downhill?
Velocomp
Velocomp CEO
Posts: 7793
Joined: Fri Jan 11, 2008 8:43 am

Re: problems revealing power downhill

Post by Velocomp »

I am very concerned that this mount, even though made of hard plastic, has flex in it. If it vibrates during your ride, this will cause problems for PowerPod.

If, when you push down on the mount, it flexes AT ALL, then it is not stiff enough.
John Hamann
FedeSp
Posts: 23
Joined: Sun Jul 30, 2017 2:51 pm

Re: problems revealing power downhill

Post by FedeSp »

I confirm that the frame does not flex I did several tests. I noticed that the writing is not parallel to the ground. I could try to put it parallel, recalibrate and see what happens. what do you say?
Velocomp
Velocomp CEO
Posts: 7793
Joined: Fri Jan 11, 2008 8:43 am

Re: problems revealing power downhill

Post by Velocomp »

Yes, please try that.
John Hamann
FedeSp
Posts: 23
Joined: Sun Jul 30, 2017 2:51 pm

Re: problems revealing power downhill

Post by FedeSp »

hello John, exit made, the result seemed improved but it was not so. Question: the wind scaling which values should have ?? because in this calibration it went to 2.8 instead of 2.1 of the previous calibration.

I'm waiting for your news, and even if you have to do new tests.
See you soon.
iBike_04_27_2018_0900_4_km_CalRide.ibr
(39.31 KiB) Downloaded 154 times
iBike_04_27_2018_0910_58_km.ibr
(558.26 KiB) Downloaded 153 times
FedeSp
Posts: 23
Joined: Sun Jul 30, 2017 2:51 pm

Re: problems revealing power downhill

Post by FedeSp »

hello john today I recalibrated the Powerpod after having dismantled and reassured everything.
I am attaching the calibration and also a ride that I did to return home.
it seemed strange to me to do 300 or a peak of 500 watts.
iBike_05_04_2018_0932_4_km_CalRide.ibr
(38.67 KiB) Downloaded 161 times
I attach everything to you.
iBike_05_04_2018_0932_4_km_CalRide.ibr
(38.67 KiB) Downloaded 161 times

john sorry, could you tell me how this second calibration looks like you?
Attachments
iBike_05_04_2018_0943_3_km.ibr
(28.86 KiB) Downloaded 173 times
Velocomp
Velocomp CEO
Posts: 7793
Joined: Fri Jan 11, 2008 8:43 am

Re: problems revealing power downhill

Post by Velocomp »

FedeSp wrote: Fri May 04, 2018 6:46 am hello john today I recalibrated the Powerpod after having dismantled and reassured everything.
I am attaching the calibration and also a ride that I did to return home.
it seemed strange to me to do 300 or a peak of 500 watts.
iBike_05_04_2018_0932_4_km_CalRide.ibrI attach everything to you.iBike_05_04_2018_0932_4_km_CalRide.ibr


john sorry, could you tell me how this second calibration looks like you?
Your post-cal ride looks fine!
John Hamann
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