Completely wrong speed with Tacx Vortex Smart

I monitor my indoor biking training using my Fenix 6 Pro and have noticed that the speed shown on the watch and that shown in the Tacx Training app are nowhere near. The watch constantly signals around 1/3 of the speed shown in the Tacx app, with an obvious detrimental effect on all the training and physiological metrics that brought me to buy this watch in the first place.
This happens with fixed power trainings, I don’t think it does with videos.
I’m pretty sure that Tacx has it right and that their app is doing some adjustment of the raw speed broadcast by the trainer but I can’t help but ask: Tacx is now part of Garmin and they can’t figure out a way to have their products interact correctly?!

0 LuizMaia over 5 years ago

I have this situation with last version of firmware too. The problem is with bike indoor app and the way it estimate time in moviment .

A alternative is the use of normal bike app with gps turned off. Your speed will become more realible.

0 ekutter-dnu over 5 years ago in reply to LuizMaia

Tioz90 How are you getting your speed to the watch? Is the watch paired to the Bushido through the Ant+ speed/cadence senors? Or is it paired as trainer? If you post your .FIT file from the F6 for that activity I can quickly take a look at how it's getting its speed data.

0 Dr Phil over 5 years ago in reply to LuizMaia

As I said to you, I don’t believe the issue is with the activity on the watch. I demonstrated just that the other day. I think it’s something to do with how you are getting the speed data to your watch.

0 Dr Phil over 5 years ago

I have a Vortex Smart but I get my speed data from a sensor on the wheel, not the trainer.

0 mcalista over 5 years ago

I haven't used the Bushido or the Tacx app, but because smart trainers can vary the resistance according to the "terrain", speed in a virtual world such as Zwift or Tacx bears little resemblance to speed as measured by turns of the wheel.

If you want to bring them closer together, try using a different gear.

0 Dr Phil over 5 years ago

Tioz90 LuizMaia

I've just done a ride on my Vortex Smart with one F6 using an outdoor cycling activity I created but with GPS turned off (I use this for my indoor training) and another F6 (my wife's but don't tell her) using the in-built Bike Indoor activity. I connected both watches to the combined cadence/speed sensor from the Vortex. I had to manually set the wheel size for both as it was on auto. I was using Rouvy for the route (The Old Abandoned Railway). Both watches recorded the same distance and speed - well off by 400m but I checked and I had the wheel sizes off by 2.

Anyway, the point is that this showed, to me anyway, that there is not a problem with the Bike Indoor activity. What wheel size setting do you have for the connected speed/cadence signal from your trainer?

0 Tioz90 over 5 years ago in reply to ekutter-dnu

Connected directly to the trainer.
here you go: https://we.tl/b-FEhiApVNXc

0 Tioz90 over 5 years ago in reply to Dr Phil

I’m connected to the combined Speed/Cadence Sensor broadcast by the trainer; I would expect that to be the gold standard to get precise data for a virtual ride.

0 Tioz90 over 5 years ago

I have just realised that the watch is communicating over ANT+ while my iPad is connected over BT. Could this be the source of the discrepancy?

0 Dr Phil over 5 years ago in reply to Tioz90

What wheel size have you set for the speed/cadence sensor in Sensors and Accessories?