Ant+ dropouts

Anyone else suffer multiple ANT+ dropouts today riding between 18:00 and 19:00 GMT? Using the same set up as last ride, but trying to determine if this is a Zwift issue or my Stages power playing up.

Set up as follows :- Surface Pro 3, Suunto Ant+ USB and Stages Ant+ power meter. Last ride out suffered no issues. Had a dozen or so drops in the hour, each lasting 30-60sec. Last drop the power kicked back in at 2000w briefly (I wish). The response to power on sprint sections also appeared a bit laggy today.

I used to have a Suunto Movestick Mini and had lots of ANT+ dropouts. As you have experienced some days were worse than others (presumably due to interference from Wifi, Bluetooth and microwave ovens). Note that it’s unlikely that anybody else would have had issues at exactly the same time since ANT+ interference is likely to be very local.

I eventually switched to a Dynastream ant usb-m stick ( on the recommendation from another vendor. I also use a USB extension cable to position the stick on the floor underneath my bottom bracket. This combination has made my setup much more reliable. Unfortunately it’s still not perfect, but I only have a dropout every few rides now.

Thanks Christian, I have a Garmin stick as well, so I will try for comparison.

I have a Garmin Ant+ and it was dropping regularly. I then moved it to a different USB slot and rebooted and it seems to be working much better. No drops on the last ride.

I am not sure what it is, but seams I also randomly loose “power” and it shows zero suddenly, then eventually picks it up again. Some times I had a feeling it’s but power tap as some kick into the pedals seamed to help. But oddly my Garmin bike computer does not have or show this problem. Also using the Suunto Movestick Mini + PowerTap (I just recently changed the batteries as I had a feeling it was low, but may be not). Computer with USB stick is sitting comfortably on my TT handle bars right where normally the Garmin bike computer is so that should be fine.

Actually, in my experience my Suunto Movestick Mini needed to be considerably closer to my KICKR than my Garmin computer. I think the Suunto is primarily designed for syncing watches that are sitting right next to the computer and as a result has a pretty weak radio. I think it’s probably worth trying the extension cable to see if it makes a difference.

I also think that switching to the ant usb-m stick made a difference for simulated riding with a smart trainer. Unlike Trainerroad, which changes resistance only every few minutes, simulations need to change resistance every second or two. In my experience I got glitches even with the Suunto right next to the KICKR. If you’re using a basic trainer with a powermeter you may not have this issue, though, since you’d only need to receive data not send it.

I wish they would support my old Garmin USB-1 stick!

This stick worked great, not loss in signal, for my own computer based riding tool I made up long ago where I used computed power (from trainer speed/power curve) and also actual power from PowerTap to ride in any of my own historic tracks virtually seeing my progress on google maps :slight_smile:

that was in 2009:

I’ve simply moved my Wifi AP further away and the surface 2 foot in front of the front wheel. All now stable. WAP is a high power unit and was probably flooding the signal.

Recent finding using the Suunto Movestick Mini in my laptop sitting on the TT-bars:

I found that when I have my hand on the handlebar very close the to Stick in the USB port it seam to attenuate the signal just enough to cause random power reading dropouts (causing VR bike stalls…).

Just leaving a few inches clear space to it this so far helped to get a reliable power reading!! Did not realized that before!

I do not know if eventually Ant+ receiver settings in the dongle via the newer ZWIFT software got adjusted, but for a while already I had no issues any more. I did no change on my side, same positions for stick and wheel!

So works flawless now :slight_smile:

I recently got the Wahoo Kickr Snap in combination with the Suunto Movestick mini. In the beginning I had dropouts every 2-3 seconds in Zwift. Updating the software on my Kickr Snap solved the dropouts for me. 

I have a Tacx Vortex using a Suunto Ant+ stick and have experienced something very similar, during structured workouts the resistance seems to work fine, however when I “just ride” there is no resistance when climbing etc. 

I tried using the IOS version and it works fine, too bad it is on my iPhone 5S so cannot see anything.

So I assume it is my Ant+ stick, does anyone know if I can just use bluetooth on my Mac instead of the Ant+ stick?

Courtesy of : Routers transmit on the same 2.4GHz frequency as ANT+ (which is the power meter uses to communicate with the head unit), and can sometimes overwhelm the power meter signal. When this happens the head unit will not be able to receive the data and will display zero values, and then will return after the interference has passed. 


There is an effective solution for this, which involves a quick adjustment to the broadcast channel of the WiFi router. Within the 2.4GHz band, there are even smaller channels present, which are numbered 1-13. Generally routers will broadcast on channels 1, 6, or 11. The ANT+ signal from the Stages power meter is broadcast on channel 10, which overlaps quite a bit with channel 11. Thus, if there are networks present on channel 11 it could cause interference problems. The easiest solution is to shift any of those networks on channel 11 to channels 1 or 6 to avoid overlap. Below is a diagram which offers a visual rendering of this signal overlap.





This is a fairly comprehensive guide on how you can make this change: