u/tri-anything-once

You may have seen my earlier post. This is an update. TLDR: Wahoo Kickr and XLab were far off in my previous test. My Wahoo Kickr and Favero Assioma pedals were extremely close. https://www.reddit.com/r/XLabsBikes/comments/1vgnaib/rs7_power_meter_vs_wahoo_kickr_ugh/

I ran the same test again with the same workout and updated testing conditions based on feedback from the community.

Result:

• Wahoo average: 145.5 W
• Branta average: 135.5 W
• Average difference: 10.0 W
• Branta lower by: 6.9%
• See also, break down by power table below

Updated testing conditions:

• Updated firmware on XLab power meter in the app
• Confirmed correct crank length
• Calibrated power meter and Kickr
• Turned off erg mode power smoothing
• Numbers exclude the first minute and the cool down

Personal conclusion: I still have no regrets about the bike but I am very disappointed in the power meter and will eventually replace it. Part of the reason is that I am a fairly serious cyclist (for an amateur) with seven years of power data. There is no easy way I have found for me to compare my new and old power numbers. As far as I can tell, Branta has no way to do a weight calibration in their app like you can do in the Favero Assioma app to better align it to my Kickr. Alternatively, I could adjust all of my training data but there is no good way that I can find to do this in Strava, TrainingPeaks, or Garmin. I respect anyone's opinion who thinks thinks a 7% difference is no big deal.

Additional Data: Break down by segment (duplicates removed)

Approx. target	Wahoo avg.	Branta avg.	Difference	Branta lower
85 W	85.2 W	81.4 W	3.9 W	4.5%
110 W	110.2 W	103.0 W	7.2 W	6.6%
115 W	114.9 W	104.1 W	10.7 W	9.3%
140 W	140.5 W	131.8 W	8.8 W	6.2%
170 W	170.8 W	159.2 W	11.6 W	6.8%
225 W	227.2 W	210.8 W	16.5 W	7.2%
245 W	249.3 W	231.6 W	17.7 W	7.1%
255 W	254.7 W	244.7 W	10.0 W	3.9%

Preface: I love the RS7 and with the price so good, I feel like I can't really complain, even if I need to replace the power meter. That said, I would like to know what you would do given my analysis.

TLDR: The branta power meter on my RS7 was lower than my wahoo kickr by an average of 11.4W. Coming from Favero power pedals, I was expecting a lot closer.

Here is the break down of the workout above, excluding the first minute (not sure what that spike is) and the cool down:

• Wahoo average: 144.3 W
• Branta average: 132.9 W
• Average difference: 11.4 W
• Branta lower by: 7.9%

Here is a table with the difference by segment (duplicate segments removed, showing only the first segment if multiple at the same target power).

Approx. target	Wahoo avg.	Branta avg.	Difference	Branta lower
85 W	85.0 W	78.8 W	6.2 W	7.3%
110 W	109.2 W	100.4 W	8.7 W	8.0%
115 W	114.9 W	102.7 W	12.1 W	10.6%
140 W	140.0 W	127.3 W	12.7 W	9.0%
170 W	169.8 W	155.7 W	14.1 W	8.3%
225 W	224.5 W	211.4 W	13.1 W	5.8%
245 W	241.7 W	226.1 W	15.6 W	6.5%
255 W	252.1 W	236.6 W	15.5 W	6.1%

Question: Does xlab/Branta have an app where the power meter can be weight calibrated?

Discussion: At this level of difference, would you consider replacing or just live with it? I know we can't necessarily know that the Wahoo values are good, but my Favero pedals are within 1-2%.