Switch from Stages L to dual Assioma pedals

Question for Assioma pedal users, recently switched from Stages G3 single sided to dual Assioma and my workouts are now a heck of a lot harder, I know Assioma are supposed to be very accurate but z2 now feels like Tempo, Tempo feels like threshold (RPE) , with the Stages the RPE and HR seemed to track with reported power for the same efforts, anyone had similar? I use dual Stages and Assioma outside and can complete workouts at my FTP, so I know, or I think it’s not me, I’m thinking they are under reading or there is a clash with my Neo2, or I’ve missed a set up step on the app, any advice much appreciated.

Whenever you switch from one power measurement device to another (smart trainer to power meter, or between different power meters like your case), it is best to redo your FTP evaluation.

Despite the manufacture claims to accuracy, along with factors like location of the power meter in the drivetrain, single power doubled vs total power vs dual power measurements, we see countless examples where power meter A gives different data than power meter B.

This is very likely in your case and means that you should not trust they match unless you perform testing to show that they do. You can do that comparison testing or just redo your FTP test of choice and start with the new data as your training guide.

Essentially, you have changed to a different “tape measure” and they are likely different by enough that they are not directly comparible.


Similar experience here moving from Stages to Assioma duo-shi - and as posted by @mcneese.chad it’s easily solved by redoing your FTP evaluation using your new setup.

I’m running 3 x power meters currently:

  • Wattbike Atom Gen-1 for indoors
  • Stages G3 L/sided for my road bike
  • Assioma duo shi for any rentals I use on vacation

With the Assioma I was able to ‘benchmark’ all three against each other to get a sense of where they stand comparatively.

Prior to this exercise, based on RPE on my own road bike with the Stages-G3 and numerous rental of other bikes abroad with power meters, my theory was the Atom under-reads power comparatively (or conversely could be argued all the other power meters I’d had used with perceived RPE were over reading).

I also know that for indoor cycling I am for the most part not as capable in terms of putting out extended power at the same level as outdoors due to the effects of heat (even with 3 x fans :slight_smile: ) - so this could also be contributing.

So for all these reasons and speculation, it was super interesting to establish a reasonably robust and reliable comparison. I did an indoor ride and used the pedals connected to my Wahoo Bolt and then sat at various power levels in steady state and compared the two outputs. I then repeated the exercise outdoors, borrowing a second headunit.

The results were as I had expected - but not entirely.

Wattbike definitely reads lower than Stages - by around 6% to 7% - the margin grew a really small amount as the power went up but broadly was around the 6% mark give or take a tiny bit and stayed fairly consistent. This aligned to what I was ‘feeling’ with RPE on the bike and seeing in bigger numbers outdoors than I could reliably repeat indoors.

The Assioma was somewhere in between - but much closer to the Wattbike than the Stages by an appreciable amount - so good to know when I’m pacing a rental bike up a long climb on vacation that I can push a slightly bigger number than my Stages would be telling me, albeit I always take any shown numbers in hand with RPE. Again this matches my RPE and ‘feel’ from recent extended hard rides abroad using them, where I saw numbers that were much more aligned to my indoor performances on the Wattbike than those I’ve had on my own road bike with the Stages-G3.

I don’t think it really matters if the various systems you’ve got read different, just so long as you know a) what that difference is and b) are confident that it’s consistent - from thereon in you can make allowances accordingly.

Obviously if someone asks me my power numbers or FTP I always go off the Stages outdoor number :rofl: :rofl: :rofl:

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