Garmin edge 840 solar and 4iiii Dropouts

Anybody here experiencing connectivity issues with the latest Garmin Devices and 4iiii Precision Dual-Sided Powermeters?

I never have a problem calibrating or having it connect intitially, but when I am riding the connection will drop and reconnect. Its very sporadic but when it happens, it almost always happens multiple times in a row (like 3-6 times in a couple minutes).

Most of the time its a very brief blip of lossed connection, but sometimes it will be upwards of 30 seconds to a minute to reconnect.

At first I thought it was the Power Meter, but 4iiii sent me a brand new one and I’m still having the same issue. The Power Meter connects via Ant+. I’m at a loss here and just reaching out to others in the community to see if anyone is experiencing the same issue.

I have also experienced the same a few times; dual sided Dura Ace 4iiii and Edge 840 Solar in combination.

I also experienced the same with Edge 520 with the old gen 2 Stages many years back, and I recall reading somewhere that the reason was that where the ANT antenna was positioned inside Edge hampered the unit’s ability to read signals from Stages, and I don’t think these units supported both ANT and Bluetooth (this was in the dark ages, before disc brakes and other modern inventions). My solution then was to swap the Edge 520 with a Wahoo Bolt.

As 4iiii supports both ANT and Bluetooth, perhaps swirtching between ANT and Bluetooth may be the remedy?

I haven’t figured out how to switch it. I can only see the Ant+ ID. When I unpaired and searched foe bluetooth sensors, it doesn’t show up. Have you done it before?

I had similar dropout issues with the 840 Solar and THM powermeter. Literally dropping out every single ride, reconnecting briefly, then dropping out again. I raised a support ticket with THM a couple of months ago which still hasn’t been resolved (I assume they’re talking to Garmin), however in the meantime I picked up a Wahoo Bolt on sale and there have been zero dropouts with the Wahoo.

If you can, see if you can borrow a Wahoo head unit and that should help determine if it’s the Garmin or the PM?

I actually have a Bolt V2 also. Ill throw it in my pocket next time and dual-record and see if its the headunit.


At least with my Stages, I had to connect it with ant+ and then set it to 1 second recording. I think the default is smart recording.

I also solved all my inside dropouts by getting rid of 2.4ghz wifi (just use 5ghz now on my Garmin and all devices near the trainer).

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Anyone has found a solution to this problem (I’m having exactly the same issue) and definitely don’t wanna drop another $$$ for wahoo computer…

Garmin is having me track my rides with ant+ debugging software tool to work on a fix. After communicating with them it was a known issue with the 1040 solar units and its just coming to light with other users with the 840 solar. Contact garmin to do the same (its pretty easy) and hopefully they will roll out a firmware fix in the future.

Batteries and updates.

Make sure you 4iiii has good batteries, no only new but a good brand. it should not be the case , but cheeper brands and have voltage stability issues.

This week / 10 day Garmin has issue a number of updates, in cluding sensiors for the 1040 , check to see what is available for the 1040

best of luck

Solid advice for sure, however I am well past the point of troubleshooting with correct updates and full, name brand, not expired batteries. This is 100% a communication issue between garmin and 4iiii products. 4iiii has replaced a PM, Garmin has replaced a headunit. Problem still occurs. Garmin has stated directly that it is a ongoing known issue and communication and debugging has commenced.