Speed wrong on Strava after TR ride on NeoTacx

Help! I’m new to TR, and love it, but the speed data it sends stava is wrong. I am riding on a smart trainer - NeoTacx 2. I normally ride around 24-28 / kms/hour, but my stava post is showing speeds of 40+. Other data seems right. I’m getting lots of comments from friends on strava, but no one seems to know how to fix this. Any advice?

This article has the info that matters:

In short, using ERG on a trainer allows a wide range of gearing on the bike, and that gear selection is what drives the Speed and Distance values presented from the workout.

  • High Gearing = High Speed & Distance
  • Low Gearing = Low Speed & Distance

Presumably you are using a big gear for your workouts (big front ring and small rear cog) when performing your workouts. If you decrease your gearing, the S&D will decrease as well.


I’ve learned to just ignore speed, distance, elevation, and calories on trainers. They are all so different to the point the data tells me nothing unless I am 100% comparing apples to apples. I know people love comparing and bragging about things like “Check out my Strava end of year stats, I did 5,000 miles on the trainer”, or “I finished a Zwift race in X place”, but it’s totally unreliable and varies vastly from meter to meter.

I set my indoor goals around time in the saddle and power numbers and only compare myself to myself now.

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For the technically inclined, there is a garmin sdk which includes a java tool to convert the fit file to a csv. I process the csv converting watts to speed based on some assumptions and then use the same tool to convert it back to a fit file. That fit file can then be uploaded to garmin, strava, etc. The end result is a consistent speed / distance based on power. **

For reference : An interactive model-based calculator of cycling power vs. speed

** Yes, it’s all make believe but it’s consistent so I prefer it over the original TR output.

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TR reports speed on the basis of your flywheel speed so its largely dependant upon which chain ring you are in and the resistance. Its irrelevant anyway you could be getting a better workout when your trainer resistance is low and the speed of the flywheel low. Programs like Zwift and RGT will calculate virtual speed on a basis of your power to weight against on artificial terrain which might for the same ride give you 24-28kph range that you would expect; at the same time as TR give you 7kph or 40kph (depending what chain ring your in and the resistance) and at the same time your actual speed is 0kph because you never actually went anywhere. What is true though is your work/ watts and that is important. If people’s comments on estimated speed that isn’t actual bothers you Strava lets you hide it now (or at least they do on a premium account).


Thanks for that. I do have premium strata so will hide it. saves people thinking commenting that I’m super human!