Power readings and distance of Trainer from Bluetooth/ANT+ device

hi, i was wondering if power readings will be lower, the further away the trainer is from the bluetooth/ANT+ device?

i am getting wildly different readings (up to 30 watts higher with the Assioma) between my Saris H2 paired to my desktop computer, and the Favero Assioma pedal paired to my fenix 5 mounted on the handlebars.

both have been calibrated, the H2 through the Zwift calibration, and the Assioma through the Fenix 5.

You should calibrate the H2 with the Saris app or the Rouvy app. Zwift calibration is notoriously awful (my H3 would not calibrate). Then compare.

Also, if the difference is at the high wattage…what is the percentage? I can be 15 watts different to my P1s at 500 watts and within a watt or two at 200 watts. At the high wattage, unless you can hold that wattage for a significant time, the differences could well be reasonable and within the tolerance of the devices.

No. The communication and handshaking between the devices is either present or not present. If your devices are within the functioning, suggested distances, the data will not be altered by the communications protocol. You can test this yourself by placing your Fenix 5 where your computer is presently, and moving your computer to a location adjacent to or on your bike. The power delta will still exist.

1 Like

thanks for the info
i will try recalibrating with the saris app.
the discrepancy is almost at all watt ranges, but does get worse the higher it goes.

Measuring power at the pedal vs the rear hub will also cause some discrepancies known as drivetrain loss.

Your Assiomas will be giving you a much more accurate power reading than your trainer.

1 Like

thanks for the replies.
i calibrated the H2 with the saris app. and no difference. 10-30 watts discrepency at any power range
i notice that the assioma jumps radically. 10-20 watts instantly, without any discernible effort changes. certainly, out on the road, riding to target power zones is 100% impossible.
assioma was calibrated using the assioma app, and using a garmin fenix 5. no difference in results
both units are set to 3-second recording.

I wouldn’t call 10-20W fluctuations “radical” - they are quite normal, your output is indeed fluctuating that much. Use 10s averaged power to filter those out.

I would trust the Assioma more than the trainer - and even more so considering you are using them outside, they become your one version of the truth. I assume you are also using them inside? If so, use powermatch, and you’re good to go.