Issue with Zwift Calibrate Spindown

Since yesterday I started with Zwift, in combination with the Tacx Flux 2 smart trainer.

After I installed the app I started a ride. But as it turns out, if I pedal quite hard, I will not get further than 18/19 km per hour.

I found a calibrating spindown based on the bluetooth connection. After I had accelerated to 37 (step 1/2) kph (then it indicates the correct speed) I released my pedals, then I came to step 3: keep the speed! 37 kph. I did this for 11 to 12 minutes and then nothing came into the picture.

I can’t go on now … am I overlooking something? And why does the Tacx indicate the correct speed during calibration and not virtually during the rides?

By the way, I put an ANT + in my laptop.

It’s better to use the Tacx app to do calibration, rather than doing it through Zwift.

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Hi Steve,

Thanks for the reply! This afternoon I’m going to have a look at it.

Unfortunately, it has not helped. Even with calibration I had to pedal extremely hard to reach 30 km / h at all. I don’t get it. Whenever I cycle a little faster, I cycle following Zwift and the Tacx App 18 km p. hour.

On Zwift I just tried (through the 5 steps) to recalibrate it. Literally lingered at step 3 for 25 minutes but no response. The strange thing is that the calibration indicates a (in my opinion) good speed …


30km/h is not slow. What speed do you do outside on a similar route?

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Bear in mind that the raw speed indicated in the Tacx app won’t relate to the speed that Zwift shows you doing, due to many factors.

See How Does Zwift Determine My Speed? - #8

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