TomTom Spark Speed Inaccuracy

Yak Jin
Yak Jin Registered Users Posts: 2
Apprentice Seeker
edited January 24 in TomTom Sports
Hi all

Not too sure if any of you experienced this, but the speed reporting at the end of an activity is wildly off. The average is correct, it is off when we go into the splits. I am sure I was not riding at 121 km/h. Same issues on running. Not too sure if it is the app or the tracker. Will be grateful for any insights.360b58d3-ab1a-47a8-973a-1edbedaf8fc9.png


  • tfarabaugh
    tfarabaugh Posts: 16,948
    They are using a different data series. The speed is showing a specially smoothed speed- this is the values that the watch is showing in the speed screen. Unfortunately, the smoothing can cause the average values to be slightly off. If you want to avoid this, you can use the lap speed or the average speed field on the watch, which will align directly with the split / lap times. To summarize, the split times will be more accurate than the speed shown in the graph.

    I hope this helps answer your question. If so, please mark it as a solution so others can look for it if they have the same question.
  • Yak Jin
    Yak Jin Registered Users Posts: 2
    Apprentice Seeker
    Thanks for the reply. Understand fully the occasional spiking, and you are right. The split times are correct. My annoyance is this occurs throughout the entire duration activity, and not an anomaly.