Garmin 820 or Gen 3 Stages issue?

Equipment
1

There is no way to post this question without sounding super douchey so I’m just going to go ahead and own it. My sprint seems to “break” my power file. There, I’ve said it. Now some context.

I’m a really big dude (6’2" & 285#/124kg). I’m very twitchy in terms of power production. My max power, as recorded by this very same power meter and Garmin is 2493 watts. On my last few rides though, during all-out sprint efforts, the head unit is showing 0 watts. In looking at the data later, for a fifteen-second window in that sprint, it shows no power data at all. It shows 500 some watts at the beginning, 623 watts after, but nothing for fifteen seconds despite trying as hard as I can. Frustrating to say the least.

Near the end of that ride, I stopped the Garmin, saved the file and started a new one, this time in the “Race” activity profile rather than the “Training” one. Not sure why this would make a difference but figured I’d try since I just started using the “Training” profile and this was a new issue. Same story though this time it at least went up to 1200 watts before going to 0, all while mid-sprint. Again, for context, I can do 1200 watts pretty easily. This was not an easy effort but no data to back it up and obviously, if it didn’t happen on Strava/TR Analytics, it didn’t happen so you can appreciate my frustration. Hopefully. Or you think I’m a douche. Fair enough.

Fast-forward to yesterday. I’m doing an effort out to the group ride and decide to test this issue. I look down mid-sprint and see 2621 watts on the head unit. Joy! It’s working again and a new power PR. Then comes two totally separate leaks on my rear tire that tubeless barely sealed up and a bailed shop ride. This isn’t enough to knock me off my cloud of wattage infused happiness. Until I get home and Strava/TR Analytics show a peak wattage 732 watts lower than what the Garmin said…

Again, #firstworldproblems, #humblebrag, super douchey, etc. I’m a horrible human for even asking but I can’t find anything on either Stages or Garmin support and given that it’s peak season, I’m not about to send either in for warranty. Anyone out there shallow enough to admit having the same issue?

2

from breaking spokes to breaking power meters! :wink: I got started too late, the only thing this clydesdale breaks are spokes and monthly records for flatting tires (although tubeless doesn’t always save!)…

Sounds like a Stages problem, give them a call.

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Oh I’m with you on broken spokes and flats. On my original wheelset I could almost snap a spoke on demand given the right short steep hill. And flats… all the time. I’ve had a great experience with tubeless. Just had a ton of miles on the Schwalbe Pro Ones so not really the tires fault at this point.

Seems likely its a Stages issue. Unfortunately, my original gen 3 is in their possession and I’m having issues now with the loaner. Do I dare ask for a second loaner…?

5

What’s your cadence like during the sprints?
I have a gen 3 on my bike and it gets confused during sudden cadence jumps.

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Another sore subject. My Connect account only seems to show Zwift rides despite lots of updating and syncing attempts.

It also quick syncing to Strava long ago. I have to plug it in via usb and turn it into mass storage mode to upload every time. Sigh.

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TR shows 97 just before, 169 during and 88 after. It’s hard to zoom in much on the phone. I’ll take a closer look when I’m at my laptop but the fact that it recorded 169 leads me to believe it’s still sending a signal during that period.

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I am a big dude too and have similar problems on my sprint. I notice the problem is most pronounced at low cadence (at the beginning of the sprint). I have a gen 3 stages. Lately for my sprint interval practice I have been sort of easing into the sprint by getting up to full sprint gradually not with a snap that I would do in the race.

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