About 400W Power limit using unlisted trainer

Hi all :wave: , new on Zwift here. Greetings from :brazil:

I’ve started on Zwift some weeks ago, and i’m really enjoying.

I’m using a trainer that I have a few years (and this trainer works great and always was good enough for me), which it’s unlisted on Zwift. Then, I would like to question you people about the 400W limit for unlisted trainers.

This limit actually avoids that I can ride some workouts, which require powers above 400W. I suspect that 400W limit affected my FTP test as well :frowning_face:; I rode around 400W for 20 minutes (image below), and maybe I could has done a bigger average power with no 400W limit.

Then, I have two honest questions: what’s the reason behind this limit, and can I disable that in some way, maybe during workouts?

English isn’t my first language, so my excuses about some mistake.

Thank you so much :slightly_smiling_face:

Hi @Tiago_de_Freitas_Lim

Welcome to the Zwift Forum.

A FTP of close to 400w is considered very high.

See this for more information https://zwiftinsider.com/are-your-power-numbers-accurate/


Hi @Gerrie_Delport, thanks for your answer and the link. Anyway, my trainer looks all good.

I’m glad to see that 400W is a high number :sweat_smile:, i had no idea about it, but is not there a way to do Zwift calculate the power above this value?

Currently i’m doing a training plan that have workouts with 600W, i will not be able to do that :frowning_face:, even that i can ride with this power

I’m attaching other image from my FTP test, to emphasize my argument, which i rode the 20m FTP test around 400W (the FTP test result was 374). Am I understanding this in a right way?

Anyway, i realized that, in fact, don’t matter how hard I ride, the power stops in 400W; it’s a blocker for some workouts :worried:

Thanks for your support

I think there might be something wrong with your setup. It is highly unlikely that you can actually ride at 400 watts for an extended time period unless you are a pro.

I would suggest getting your hands on a power meter and see if you get get your setup corrected.

In my opinion, if you are using virtual power you should be training using HR and not power since it is not accurate.


If your trainer has a resistance leaver you can set it to the maximum setting and re do the FTP test. Your FTP will be lower and you won’t hit the 400w limit.


Hi @Paul_Allen, thanks. Actually i’m not a pro :sweat_smile:, despite that I have ridden long distances for some years, and training indoor bike at gym. I’ll double-check my setup in order to figure out something wrong: thinking:, maybe i’m using resistance control in a wrong way. Your suggest about HR looks interesting; actually I never have mattered so much to HR in bike training

@Gerrie_Delport in order to control the resistance, I don’t use so much the resistance leaver from the trainer, just the gears of the bike. My bike has 3x9 gears and I always use the highest. I thought it would be equivallent

Anyway, actually there is no way that I do an workout with, let’s say, 500W? :pensive: What is the reason for this limit?

Thank you guys

The reason is that power not from a power meter is highly inaccurate and therefore it is not trustworthy. So to avoid people ruining events and rides(which happens anyway with the limit) the 400W limit exists.


The higher the wattage the more inaccurate it is. I agree it’s unfortunately that you can’t see if you are doing parts of the workout correctly.

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Put the resistance leaver in the highest setting (most difficult) and leave it there. Then set your FTP manually to 50w and re do the FTP test.

Then your workouts should be better.

Don’t ajust the resistance leaver.

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Wow, I guess that in this way my FTP test result won’t be greather than 100W :rofl: I’ll do it, thanks a lot guys!

At least you will be able to do meaningful workouts.