What max watts on dumb trainer from list

Doesnt matter. Zwift only read power from trainer. Same power will be on tacx, zwift, garmin, wahoo etc.

This is incorrect.

The Tacx Booster is a classic trainer and Zwift will use Virtual Power/zPower.


Just so you are aware:

For virtual power like yours:

Zwift takes the wheel speed broadcast by your speed sensor and the power curve of the trainer you select on the Pairing Screen and converts that to virtual watts. With those watts, the weight entered, height entered, in-game bike used, in-game drafting (Tri and TT bikes get no drafting boost), in-game wheel set, in-game road surface, and in-game virtual elevation changes your in-game speed is determined.


But here https://zwift.com/hardware says that booster doesnt support Zpower, only estimated power.
And yes it is classic dumb trainer

They are both estimated power, not really any major differences between the 2 terms.

Oh, thanks. So if trainer is in list, it can produce in zwift more then 400 watts, right?


Hey…I’m re-taking again the topic bcs I still have one doubt…I understand that tacx booster (dumb trainer) with sensors should work with z-power, but with this trainer you can shift the resistance between 10 different levels.

how this is informed into Zwift?

is it that you should fiix the resistance in this is why the max power is limited to the corresponding curve based on the graph above?

thanks for response…if someone have any :slight_smile:

Hi. So i got my booster. Zwift will ask you to set level 2 on your booster. So u will abble train with zwift only on 2nd level. And it is really noisy when your wheel spin fast. So I use trainerroad on level 4-5 and it is very quiet.

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Thanks Alexander…so you mean Zwift only knows the power curve for level 2, right?..

and where is zwift asking me to to so? I’ve not seen any screen message or so, once I’ve choose the trainer, where this is mentioned… :roll_eyes:

Good morning @F_Buyse

Welcome to the forum.

You will set your trainer on the setting as defined in Zwift and leave it on that setting forever.

This is a very handy video to help you setup your trainer.


Thank you Gerri, …I did not realize that “Use Setting 2” refers to resistance level 2 on my trainer…thats’ 100% clear now…


Is there not a way you can change the trainers setting and letting zwift know ? Because in setting 2 I spin like mad

Because I can’t get higher than 390 watts without spinning like froome.

It depends what trainer you have. If its booster your only level is 2. Maybe later zwift will make anothers level.
If you have another classic trainer just choose it from the list, and zwift will tell you what level you should use.
When I do a finish sprint on my booster its like earthquake))

Yeah I’ve got a booster, it’s a shame we can only get up to about 400 Watts though

Agree. This problem can be solved by buying powermeter

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I tried doing a sprint in setting 3 and it caped the watts at 390 ! Then tried the taxc blue motion and some other taxc trainers also in setting 3 and got up to 600 watts !

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So I think I might try using an other taxc traîner in setting 2

Then you should use level that zwift will said for that trainer. It may be 4 or 5

All trainers has a different Speed/power curve. By selecting a trainer different from your real trainer you wont have accurate power numbers and will probably get flagged while riding.


Last winter season I had a Tacx Blue Motion and a speed/cadence sensor.
I put it on setting 4 which is what zwift tells you.
I could get the 800W badge one time when sprinting bad.
I always wondered if these power estimation were right.
So for this season I got a Elite Direto X (with OTS powermeter).
With this trainer I got the 900W and 1000W badge also.

So no, a supported classic trainer is not capped at 400W like an unknown trainer.

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