Using a Stages dual-sided crank PM and a Garmin Edge 530. Firmware up to date, calibrated, crank arm length is accurate to my knowledge, etc. PM seems to be reading 10-20% low at consistent endurance pace. If I switch to only displaying the left or right crank individually the right side reads extremely low (maybe half of what the power “feels” like) and is very obviously inaccurate. Left side seems to read closer to reality. Does anyone know if this reading is getting distorted by the cranks being paired together, or is there possibly a problem with the right side that is causing the overall reading to register low?
Do you happen to have one of the Shimano crank versions with known power data issues originating from the drive side crank arm asymmetry?
Hmmm. Not sure. I know it is a Gen 3. How would I check that?
There is a discrepancy in the zero offset. Left = 903, Right = 934 … there or thereabouts. But I read that was within a normal range of differenciation.
Not enough info. Which group (specifically the crank) is installed on the bike?
It’s a Shimano Ultegra. I bought the bike used from a friend and I don’t have original paperwork.
Better, but still not enough info. Older Ultegra has known issues. AFAIK, the latest version is better.
This is a picture of the latest Ultegra that has good dual power data:
Here is a video on an older, bad example:
This is a picture of the older Dura-Ace, which has the same shape as Ultegra, and is know for BAD data:
I didn’t watch the entire video but I believe it is the newer version pictured above. It’s 12spd, and I’m pretty sure (bike is not in front of me) that the placement on the crank is the same. Closer… Warmer… ?
Perhaps close enough. If it’s 12 speed and essentially the new one, the usual recommendation would be to contact tech support. Easy, other than the fact that Stages is in a state of disarray. I have no idea if they are even open for support, but that would be the typical place to start for any current power meter.
Well. I confirmed it is the new one. And I’m aware of the lack of tech support. That is why I posted here. Do you have any experience with the question I posted, which was- If you isolate the power reading on a Garmin to the individual side, will it read that side or does it get all weird because of how things are all linked up?
Sadly I don’t have that level of info. I started with the key issue of which PM you had because if it was the old one, there are known issues. So it was worthwhile to zero in on that specific as the foundation.
But since you have the new one, I don’t know what to do about the issues you see. Hopefully someone else knows what to try.
No worries… Appreciated! I am coming from dual Favero Assiomas, which I’ve taken through the wringer on/off road for about 5-6 years, and are somewhat suspect. They were reading 10+% lower than my brand new Saris H3. I haven’t put the new bike/PM on the trainer to try to triangulate yet.
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