Saris/Cycleops Powertap C1 Vs Magnus Smart Trainer Power - Which to use on SF?

Probably a question that gets asked all the time, forgive me if it is redundant. Which power reading should I use on Sufferfest - The one from my bike’s PM or the Smart Trainer PM?

I recently installed a Cycleops Powertap C1 power meter on the bike I have on my Cycleops Magnus trainer and connected to Sufferfest. The readings from the bike PM vs the trainer’s PM are almost 20 watts different, fairly consistent from low to high output with the trainer’s numbers always lower.

I did try starting a workout today using the bike’s power meter on Sufferfest, and it connected just fine and the readout was steady, but the trainer didn’t provide feedback despite being in ERG mode so I switched back to the trainer’s power meter.

I would assume that I would want to use the bike’s power meter numbers for training since that’s what I will be using outside, but looking for your feedback and experience. Thanks

Sufferfest doesn’t have power match as a feature yet (as far as I’m aware right now), therefore, when using ERG mode, you should use the trainer power for control/reporting to the app.

If you want to run another power meter in parallel, you should connect that to your head unit or sports watch (or similar).

Thank you for that Titanicus. So if using a power meter on the bike, basically it’s limited to just monitoring on a head unit and there’s no functionality between it and the Sufferfest app correct?

The only challenge that presents for me is figuring out what to do with my targets outdoors. Currently my Sufferfest target values are synced to Training Peaks, which is then uploaded to my Lezyne for outdoor training. Essentially that means that my target power values will be met prematurely outside. Would I simply manually adjust those in training peaks do you know?

This is really only true in ERG mode, where the app needs to have the same unit to control and receive power data from.

If you ride in level mode, you can use your bike based power meter as the power reporting device with no problems.

Training Peaks can allow you to set up power zones for custom activities, so you can have different zones for “indoor” and “outdoor” activities.

You may have to choose which activity group each workout belongs to after your TP sync.

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