Losing watt connection

I have a Wahoo kickr and just set up Zwift and went for a brief ride. Zwift kept getting disconnected from my watt output and my rider would stop or slow till it picked it up again. Is this a function of how close the ant+ dongle is to the trainer? My other functions seemed to be working.

yip had the same thing. I’m also on a kickr and found if sometimes there is an obstacle between the kickr and the ant+ dongle it can cause this to happen. the closer the dongle to the kickr the better I think.

It appears that other people including myself have the same experience. It happened to me for the second time tonight. Lost wattage briefly, my guy stopped. When the wattage came back, my kickr was stuck on the same resistance level throughout the route. I had to exit the program twice to have the proper resistance back. One funny thing, when the wattage came back, I received a gorilla achievement for reaching 1800 watts. I checked my strava upload, I have a max wattage at 1887. That’s probably not a bug lol.

i’m luck in that i use a mac keyboard that has usb slots. i make sure my keayboard is close to the Kickr before i start the ride.

i think you can just get some cable to extend the dongle though.

not saying that his is the cuase though - it could be connection speed.

Yes, get a USB extension cable to move your ANT+ dongle as close to your bike as possible.

It also doesn’t seem to be a good idea to run Pandora over wifi during the ride. I have my ant+ dongle on the floor under my bottom bracket, but had dropouts the last two rides. I realized the main change is I was listening to music during those rides.

WiFi and ANT+ use overlapping frequency bands (2.4 GHz)so it’s entirely possible for one to interfere with the other. Typically that results in WiFi blanking out ANT+ since the WiFi transmitter is more powerful. I had a big problem with that while using TrainerRoad at my old house.

One thing that can help is to move your WiFi router off of the default channel, usually 2, into one of the more middle-of-the-spectrum bands like 5 or 6. Otherwise, simply separating the two of them is the biggest help. If you are using a laptop connected via WiFi and an ANT+ dongle you will be far better off if you get a USB extension cable and get the ANT+ dongle physically as far from the computer, and thus the WiFi antenna, as you can while getting it as close to your KICKR as possible.

One other idea regarding the overlapping spectrum issue. A lot of newer routers are dual band and can utilize 2.4GHz or frequencies up above 5GHz. If your equipment supports it on both sides, i.e. computer and router/hotspot, you can switch over the 5GHz spectrum and that should alleviate the problem.

Unfortunately there are too many walls between my router and garage to use 5GHz. I’ll probably experiment to see how much traffic causes problems. Just using Zwift and the mobile client seemed to be ok. It’s not until I added Pandora into the mix (on the iPhone) that I got issues.

My Ant+ dongle is on an extension cable and is closer to the KICKR than either the laptop or iPhone, so I was hoping that would help with interference. I guess wifi power is a lot higher than Ant+, so it isn’t enough.

@Christian - Not sure if it’s worth the effort and expense, but if it’s something you’d like to get working perhaps you could install a 5GHz WiFi repeater in your garage? Depending on physical layout that might solve the problem.

I too am having this issue. Have the kirkr and my power keeps dropping. I was told to move the ANT stick closer, but the thing is…I used the kickr with TrainerRoad a bunch before and have never had this happen once. Not sure why it’s happening only when I use Zwift?

The difference is that TrainerRoad doesn’t communicate with the KICKR as much. Zwift is sending updates every time the slope changes (and potentially when you enter/leave draft although I’m not sure they’re doing this). TrainerRoad only needs to send updates at the beginning and end of intervals.

I suspect that when the updates come more frequently it’s easier for one to get garbled or maybe collide with an outgoing power update. For some reason the KICKR seems to switch back to resistance mode under these conditions.

My current setup using a digikey ant usb-m dongle under the bottom bracket has been reliable, though. I’ve only had two or three dropouts in 550 miles on Zwift (and those were when I was trying the Pandora streaming).

If I get motivated enough I’ll pull some cat 5e cable to my garage so I don’t have as much wifi interference.

One last note: this issue isn’t unique to Zwift. I use another simulation program from VeloReality, and had the same issues with that even when the setup worked fine in TrainerRoad. I switched to the current setup to solve those issues.

For me the problem is unique to Zwift unfortunately… I use the exact same setup for Sufferfest and I haven’t had a single drop in the first 10 rides. I tried Zwift 3 times now and I can’t ride 500m without a few drops! I hope I’ll find a solution because otherwise I don’t think I’ll keep Zwifting :frowning:


Happened to me today also - four or five times in a row, even though my ANT+ dongle is within a foot or two of my trainer.  I tried unplugging the USB, big mistake.  Lost the ability to reconnect my trainer, and thus had to end my ride when I was trying to do the Trek 50k challenge :frowning:

All of a sudden…started having this problem. I’ve been using wahoo with zwift for almost 2 years without issue! I’m going to try the usb extender to see if it woks on my lap top. I have no issues when I use my iPhone…ugh! :frowning:

I have the same with my Elite Direto, not to mention I need to get to the bottom of the cassette, 50-11, in order to put some 300 watts when it’s 0%.

I have had the same problems, but, as of this morning, I am cautiously optimistic I just resolved it by switching from 2.4 to 5 GHz wifi frequency, though this might not be an option for those without the ability to switch wifi frequencies.

My typical, current set-up is outside my house in an unheated shed disconnected from but near the house. The shed is lit by a fluorescent tube light (possible interference issue?). Normally, I was using an ANT+ dongle on the end of a 6-foot usb cable and make my power, trainer, heart rate monitor, and cadence sensor all paired by ANT+. My early 2015 Macbook Pro laptop is plugged by HDMI cable into a HD widescreen tv and the usb cable with the ant+ radio/sensor on its end is plugged into the laptop, too. Finally, I have a box fan for cooling (again, possible interference issue?).

About 14 months ago I had located my set-up in my home, quite close to my wifi router/modem. About that time (or maybe a little bit before then), Zwift had made some updates that made it possible to use Zwift with a direct bluetooth connection. So, hoping to reduce all the cables and such, I tried it but found that I could not hold all four inputs (power, trainer, heart rate monitor, cadence sensor) unless I switched to a 5 GHz wifi frequency. Thus I concluded that interference was the problem. Fortunately, I was close to the router, so I could switch to 5 GHz (which does not travel as far through walls as 2.4 GHz does). But when the weather cooled down enough to move the setup back outside in the shed, I couldn’t reliably get the 5 GHz wifi signal, and since I was having interference on 2.4 GHz, I went back to using ant+. 

Like others, everything was working fine for awhile, but then I started having major power drop-out issues, and, as time went on, they became more frequent and more difficult to resolve. Early drop-outs would typically automatically reconnect, and I’d simply have to bury myself trying to catch back onto the group that dropped me during a 5 second power-drop. But the problems got worse over time to the point that I’d have to restart everything just to get reconnected, and lately not even that was working. In fact, just a few days ago, I couldn’t connect at all.

At first it seemed that I made some headway by no longer using the cadence sensor, thinking that one fewer ant+ signal would be easier to process. I also thought I might be getting interference from the fluorescent light in the shed or from the wide-screen tv I use. But as of a few days ago, even after shutting off the light, disconnecting and shutting off the tv, unpairing the cadence sensor, AND unpairing the heart rate monitor, I was still unable to hold a connection either using ant+ OR using bluetooth. 

Then, I tried Zwift using my wife’s laptop and was able to make all 4 connections (power, trainer, heart rate, cadence) and hold them no problem. So I thought my computer was corrupted somehow.

Viewing the use of my wife’s computer as only a temporary solution, I went back to my computer and tried “resetting the bluetooth module,” trashing my bluetooth preferences, trashing the Zwift file called “knowndevices.xml,” trashing the Zwift filed called “prefs.xml,” making a new user on my laptop from which to run Zwift, setting my Mac’s SMC (system management controller, analogous to the former PMU, power management unit), resetting my Mac’s PRAM, and running the Disc Utility to repair permissions and to repair the start-up disc. None of these things worked.

Then, it occurred to me that her older computer does not broadcast as strong a wifi signal and is therefore less susceptible to interference. Moreover, I hypothesized that the gradual deterioration of the usability of Zwift was due to Zwift updates that demanded more and more bandwidth, raising the potential for more and more interference.

Although I had previously had problems connecting to the 5 GHz channel from my shed, I have recently switched modems to one that I believe is more powerful, so I decided to try again, this time logging into Zwift from inside my house close to the modem broadcasting 5 GHz and then carry my logged-in laptop out to the shed, where it held the wifi signal fine at all 4 bars of strength, enabling me to ride Zwift for an hour this morning with all 4 sensors connected by bluetooth, the tv plugged in and on, the fluorescent light on, and the fan on. Yay! I hope it sticks.

Glad the switch to 5 GHz worked for you Andy.  In my case, I’ve always been using the 5 GHz channel and had no issues until this past week where I suddenly get several dropouts throughout each ride, some of them being 5 to 10 seconds long. It’s absolutely infuriating.

Nothing has changed in my setup so I have to assume it’s something on Zwift’s end.  Server issues perhaps?

Bummer, Marko. Is it just something on your trainer (power or resistance) dropping out or are multiple sensors dropping out simultaneously? If the former, perhaps there is something wrong with your trainer, although I assume you have thought of that.

I am not an expert on the matter, but it seems that Zwift simply processes the data that it is fed, and thus that drop-out problems are likely to reside outside Zwift itself, such as with the trainer, other sensors, or their connectivity. Have you considered a “Powerline Adaptor,” which would enable you to make a hard-wired connection to the internet and avoid wifi altogether?

It has only been the power dropping out.  The trainer is only a couple months old but I guess that may be the issue.  I’ll wait it out and see if maybe it’s a Zwift thing. People have been complaining about server issues recently.

I honestly don’t think it’s a Wi-fi issue so I won’t be hardwiring the connection.  The trainer is set up a few feet from the router and I’m getting consistent speeds of 200 mbps.