Peak power lower on Strava vs Wahoo Bolt

Does anyone else find that Strava “trims” peak power from what is displayed on the bike GPS? I’m using a wahoo bolt and a 4iiii power meter and find peak power always lower on Strava. Here is an example from today:

Obviously this is really important as I’m unable to flex to my friends how powerful I am. So any help would be appreciated :joy:

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Yeah mine does that as well. Just upload that screenshot to your ride so you can flex on them with a picture :grinning:

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I assume Strava is 3 second power rather than 1 second?

True power doesn’t drop that quickly, so 3 vs. 1 second smoothing should only make a difference if there is an artifactual power spike.

To determine the root cause, best thing to do is download the data and inspect it. That would show whether the screen or Strava are faithfully reporting what was recorded, even if the latter is wrong.

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No issues with my Garmin, max power matches between bike computer, Strava, Garmin Connect, TrainerRoad, etc.

I’d report it to Wahoo.

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Lol, it’s a wahoo!

Strava recording/analysis is hopeless I find. I would say the Old’s comment is possibly on the right track. My Lezyne and 4iiii combo has recorded a couple of 1800W “max power’s” when in reality I’m topped out around 1200W.

I’m not sure Strava is clever enough to be doing it on purpose though :man_shrugging:.

Strava munges the data a little, and thats why I mostly ignore it. For example a zone 2 ride from earlier this week:

Data Garmin TrainingPeaks TrainerRoad Strava
Avg Power 170 170 169 174
Normalized Power 185 185 184 180
Max Power 1008 1008 1008 1008

Strava is off on everything except Max Power.

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Strava doesn’t use Normalized Power. It’s a ripped off of xPower, Dr. Skiba and PhysFarm Training Systems. Ripped off because there’s no credit given. Xpower is 25 second rolling average as opposed to 30 second rolling average for Normalized Power. The rest of the algorithm are the same.

Gaps in recording, ride status, are automatically corrected when uploaded to Garmin (from Garmin headunit), Training Peaks (WKO), and Trainer Road. Raw files are not corrected when uploaded directly to Garmin and Training Peaks. Workout files from Trainer Road are corrected not raw. WKO maintains the raw dataset but ride status are based on corrected.

Gaps in recording IS NOT Garmin Smart Recording. It’s Rx or receive fail where it just didn’t pickup and usual one second in duration.

I have also experienced this same exact problem using a Wahoo ELEMNT Roam.

I’ve also noticed this - one possibility I could guess is that the file export “snaps” the data to a 1-second grid - whereas the Wahoo may be internally receiving and processing power data at a higher frequency? In which case internally, it is able to track an absolute peak value even if it was only observed for a fraction of a second, and once averaged to 1-second reporting, that peak gets diminished. I haven’t been able to find anything that confirms the actual sampling frequency - could also be PM dependent.

The correct solution to flex on your feed is to take a photo as shown above - because your friends are not all opening your rides to look at your max power :smile:

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Your diagnosis here seems reasonable.

However, if the issue is one of time resolution, e.g., Wahoo devices are recording data every 0.1 s and Strava only interprets data every 1 s, I would expect Garmin devices to have the same problem.

Can anyone with a Garmin device weigh in? Have you observed discrepancies between max power on your head unit and that reported by Strava?

Never, in 3 different Garmin head units through the years.

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Or it could be that Garmin only collects the data or processes the displayed data in 1 second averages as will be exported before displaying it?

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Same here, no issues with 2 Garmin edge units over 5 years.

Strava has some interesting analysis issues, but off the top of my head its a pretty short list

  • how it calculates speed for leaderboards on very short segments
  • lack of control over y-axis on graphs
  • lack of customizable HR zones
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Never an issue with Garmin & ipbike. fit is at 1 second interval as well as tcx & gpx. You can have multiple data points over the second using Ant+ but I believe its just averaged over the one. BLE is same frequency so should be sub second recording and porting data out is truncated to one. Pretty dumb if it’s displaying max and porting average over the second recording…

I believe the answer here is that Wahoo’s Max Power field is reporting Pmax, which is the max power for one full pedal stroke, which usually less than 1s


It’ll never match up. The recording frequency is fixed but your cadence isn’t. The recordings can be anywhere along the circumference. It just displaying instantaneously peak for the recording period. Only lab stuff, SRM and maybe Stages, is setup for true Pmax.

It will never match up to the 1 second power, but the Max Power from the headunit matches pretty closely to the model derived Pmax value I get from WKO5

This might be right.

I got 1404 on my Bolt, and on training peaks, than I got 1375 on strava and trainerroad.