Different FTP, indoor and outdoor setup

Hi guys,
I’m a new TR user and have a question.

I have two setups:

  1. Indoor - Allez without Power meter + Tacx Bushido Smart
  2. Outdoor - Tarmac with Quarq Power meter

I just did ramp test on my indoor setup and measured 243 Watts of FTP (similar result as I had on Sufferfest)

My outside FTP is 285 and even Trainer road estimated it to 299 Watts based on my imported activities.

One of the main reason why I moved to trainer road is outside workouts because I want to combine TR indoor and outdoor.

Does the TR have something to cover that?

Training peaks has different FTP settings for MTB and Road so I use MTB profile for indoor rides?

(Bonus question, can I trust this TR FTP estimation from the imported ride? I averaged 275 watts for 1h and 15min)

There are a couple factors at play here:

  1. Different devices in different environments will report different power values.
  2. Lots of people seem to observe higher power numbers outside than inside.

There’s a bunch of existing discussion. If you can use the Tarmac with the power meter on the Tacx, you could set up Power Match and at least have a consistent power source. If you can’t, use the 243 number indoors, and bump it up when you go outside. TR FTP tests are for calibrating your workouts on the device you’re using to train, so it’s important to use the number the device gives you.

TR doesn’t plan to support multiple FTP profiles.

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Welcome to

TR! Great questions, you are not going to regret TR. From the FTP-values, it seems you are already a seasoned rider.

See also here:

Your FTP Improvements

First, yes, TR makes it very easy to do the same inside workouts also outside, and most workouts have an outdoor equivalent, see here:

Outside Workouts

With regard to FTP differences inside and outside, there are a couple of factors to take into account, but probably ou already know this:

  1. Your trainer may underestimate the Wattage you actually deliver. Some people have been reporting this (I also tend to experience this) for the Tacx Neo 2.
  2. Riding indoor is more strenuous than riding outdoors as you are not putting “a bike in motion”. In ERG, your trainer more or less falls still when you stop pedalling, whereas outside of course your bike keeps going when you keep still. That’s why TR says that for many trainings you could do the equivalent workload 1.5 times longer outside.
  3. There may be actual power differences between your wattage meter outside and inside, and this may depend on how imbalanced your left/right power delivery is (I have no experience with Quarc, so I don’t know whether it measures only left like 4i or whether it measures both sides).

Now, the ramp test may or may not be a good reflection of your FTP. Riding involves more than your FTP. For example, some riders are more suited to ride closer to VO2, whereas other people are more suited to endurance. The ramp test is a VO2-intensive test. If you are not suited to that, it may underread your FTP, see here:

Best FTP Test Ramp or 20 Min

Also, google on the forum for “ramp test” – there’s many topics covering ramp tests. Some people say it’s the mental aspect that’s killing them, some people say they can easily ride their FTP but the ramp test consistently provides lower readings.

Finally, on the assumption that your ramp test IS an accurate reflection of your true FTP, it can be that both power meters - your trainer and your Quarc - have a consistent difference between them. This does not help with finding out what your true FTP value is, as one is higher and the other is lower. But you can do either of these two things. First, typically, power meters can be provided an offset, which means the power reading is increased or decreased, based on a multiplier. Second, you could systematically increase or lower your FTP on TR manually OR increase the % intensity during a training (e.g., train at 105% or 95%, for example).

Some people report that power differences between meters increase when they deliver more power. For example, at 100 watts, the difference may be 10 watts, but at 200 watts, the difference may be 30 watts. In that case, the difference increases to the extent that the absolute power that is delivered by the reader also increases. I do no know how to fix that.

You could use software to measure power readings of both meters simultaneously. I believe Zwift in combination with Zwift Power could do that. I have not done this myself, but dcrainmaker does this. So it should be possible. Then, you can check for yourself what power values both meters are reading, and you can correlate them with each other.

Hope that helps. TR is amazing.

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Guys thank you a lot!

I put Tarmac on the trainer and looked at the numbers and yeah… there is a different readings between power meter and trainer.

@ellotheth you suggested to tweak outside workout. What would be the easiest way to do that? I looked in garmin connect and I cannot change the numbers.


Hey all!

This topic is discussed at length over in an existing thread. You can check it out here: