Compare trainer power to power meter?

Is there an easy way to compare power measured by the Neo 2T trainer with the power meter pedals on my bike? Last week I did a trainer workout in erg mode with 6 minute intervals at 250W, and even the first interval felt like a struggle. Then yesterday I did an outdoor ride and on the first climb I went 10 minutes at an average of 271W, and that felt much easier. I know that due to drive train friction losses, the trainer will always read a few percent lower than power meter pedals but still based on perceived effort it seemed like a large difference. So I'd like to do a similar workout again, and record power from both the trainer and power meter simultaneously to see how much they actually differ.

  • Yes there is.

    Make garmin edge or other computer conrol the trainer on erg mode.

    Take the power readings on your power meter. Ask edge control trainer  for example 250w on erg mode.

    When power readings are stabilised  (takes about 5-10sec.) hit lap button and pedal for example 5min.

    Hit lap button again and you get 5min. lap that gives power readings on your pedals.

    On the fly results you can choose "lap power" datafield on your edge.

    Choose small ring in front and straight chainline to get best results.

    My power2max powermeter shows 5% bigger readings than neo2t.

    On strava you can see easily that 5min. lap average power.