Big power differences between Favero Assioma and Newton

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Guidob
Posts: 27
Joined: Sun Oct 21, 2012 9:26 pm

Big power differences between Favero Assioma and Newton

Post by Guidob » Sat Aug 11, 2018 2:12 pm

I just bought a new bike, moved my old Newton to the new bike and recalibrated. The power numbers from the new bike are consistent to my previous bike for 5 years. Everything seems ok. Then two days ago I installed Favero pedals with the idea of eventually adding an Aeropod with the pedals. However, I am finding huge differences in power between the pedals and the Newton, 50 to 150W. I'm trying to figure out if the Newton has been that far off for years or something is off with the pedals (or maybe both).

Attached is the ride file for a 21 mile ride. The heart rate monitor took about 6 or 7 minutes to sync, but everything else synced fine. To compare them I did a number of sprints and harder efforts.

Average power Newton: 260W, Favero: 197W
NP Newton: 305W, Favero: 242W
Max power Newton: 945W, Favero: 814W
Peak 1 min: Newton: 463, Favero: 364W

I realize the Newton is rather old, but the numbers I am seeing today from the Newton are consistent with what I have seen for the last 5 years.
Any thoughts? Which is right?

I have also attached my cal ride from last week.

The bike is a fairly aero, Cervelo, 28mm Schwalbe One, Zipp 303 Firecrest.

Thanks
Attachments
iBike_08_04_2018_1532_3_Miles_CalRide.ibr
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iBike_08_11_2018_0837_21_Miles.ibr
(303.09 KiB) Downloaded 8 times

Guidob
Posts: 27
Joined: Sun Oct 21, 2012 9:26 pm

Re: Big power differences between Favero Assioma and Newton

Post by Guidob » Mon Aug 13, 2018 10:36 pm

Is it possible that because the new bike is more aero, from the frame to the Zipp wheels that it is not calibrating correctly? I also entered that I have 700x28mm tires and maybe it believes those have a higher rolling resistance, even though they don't when paired with the Zipp wheels.

If the Newton thinks the bike is less aero it may calculate the power too high.

Velocomp
Velocomp CEO
Posts: 5193
Joined: Fri Jan 11, 2008 9:43 am

Re: Big power differences between Favero Assioma and Newton

Post by Velocomp » Tue Aug 14, 2018 9:55 am

I used the "check calibration"command to dial-in your Newton.

The CdA drops down to about .34; when this change is made, the two devices match closely.

Make sure your Favero is properly calibrated; if it is, then this profile will keep the two devices close.
Attachments
Guidob.ibp
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Guidob_08_11_2018_0837_21_Miles.ibr
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John Hamann

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