Sensor connection drops

hello everyone,


just did my first indoor trainer and zwift ride yesterday. Unfortuantely roughly every 7 minutes my sensor data was no longer being reflected on my and as my avatar would stop cycling… 


my set up is as follows;

new tacx flux smart t2900

polar h7 hearthrate monitor

connected through ziwft mobile link with sensors connected from tacx utility app and polar beat (all bluetooth connections)

zwift mobile is ran on an old iphone 5 which I dedicated to the indoor trainer set up

my lenovo t440 laptop runs windows 10, is fully up to date.

both my phone and laptop are connected to the same wifi network


from my strava I noticed there where a number more drops, i.e. in cadence, then what I experienced in zwift. Since the drops occur on both the polar sensor and the tacx sensor at the same time, my assumption is that the issue is in the link between my iphone 5and my laptop… I also noticed that when my avatar would stop riding, typically all sensors where still reflected with values on the mobile app on my iphone.


I already ordered an extra wifi access point and will try again later. Any advices where I would have to go and check next? Is this a familiar thing? 


Would like to be sure this is solved before becoming a paid subscriber…


link to strava details:



OK, I have a question.

You said “connected through ziwft mobile link with sensors connected from tacx utility app and polar beat (all Bluetooth connections)”. I am not following this because Bluetooth can only connect to one device or app at a time and if the sensors are connected to the Tacx Utility App then how are they connecting tot Zwift through the ZML?

I would suggest changing your setup if possible. Using a USB extension (to get the dongle as close to the trainer as possible) and an ANT+ dongle would eliminate the need to use the ZML to bridge the connection for the trainer. You could still use the ZML to control aspects of the Zwift app running on your PC. What are you using for a cadence sensor? If you are using the trainers estimated cadence I would suggest getting a dedicated cadence sensor for increased accuracy.

Hi Paul,


that may be the cause of my connection issue indeed. 


My understanding is that, when using bluetooth, only apps from the manufacturar can pair with the sensors. ZML then reads the values throuh those applications.


before going the ant+ route I,m googling for sole instructions on how to connect sensors to zwift through zml.


thanks a lot for that insight!

That is an incorrect assumption on how the Bluetooth signal gets to the ZML and to the Zwift App.

You need to make sure that the trainer and HRM are NOT connect to any other device or app including the Tacx Utility App, they  ONLY should connect to the ZML. The trainer and HRM will only connect to the ZML and bridge that connection to the Zwift app over WiFi.