Ant+ dropouts with Zwift but not with Trainer Road

OK, so this is in some ways a question about Zwift. But it’s more about Ant+ connections…

Basically, I’m getting dropouts from my Garmin power meter when I use Zwift, meaning that I keep grinding to halt in the middle of rides. I contacted their help and they sent me to their standard page which says (and I paraphrase) “Fans, any electrical device, your dog, you moving your legs may all interfere with Ant+ or BLE signals, so please spend 15 fruitless hours moving cables around before bothering us with your problem again.”

What I’m basically trying to do is prove that it’s a problem specifically with Zwift - because I use the exact same set-up with Trainer Road, and it all works fine with no dropouts.

Would it be possible to ride on Zwift and simultaneously record on Trainer Road (e.g. just find a random long workout and run it in manual mode with only my power meter paired), and see if the dropouts happen there as well? Would that “prove” anything?

You can do that, assuming you have two ANT+ dongles. One will be used by Zwift, the other by TR. If the two dongles are identical and located in the same place, you can prove (or disprove) your app-related hypothesis.

This said, making sure your ANT+ antenna is close to the devices it connects with is indeed the first logical step. The two apps may not perform the same way on a signal dropout, making it not as obvious as it seems to say that one is disconnecting while the other isn’t.


I fear that this would invalidate the integrity of the experiment… it isn’t possible to run 2 programs off the same ANT+ dongle then?

No, you can’t have 2 apps connecting to the same device over the same antenna.

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Oh that’s a pity.

I’ve emailed them back anyway to point out that none of their troubleshooting really applies, and that Trainer Road works fine with the same equipment. I expect I’ll still get fobbed off with “have you tried moving all the electrical devices in your house into the garden and turning your fan off? Give it a go and let us know how you get on.”

I don’t think they can solve it for you. I"ve had similar problems, and you’re on your own. Antenna position is important. This said, what device are you running Zwift on? Is BLE an option?

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Bluetooth isn’t an option because it plays havoc with my bluetooth earphones. Literally just makes them repeatedly connect and disconnect to my phone.

(Again, it’s only Zwift where this happens. Trainer Road I can keep bluetooth on and the earphones work fine.)