Power comparison with Vector 3 Pedals


I got my 2T today and did my first ride using TrainerRoad. I used the 2T as the power source in Erg mode connected to TrainerRoad, with my Vector 3 pedals connected to my Edge 1030. There was a significant defference between the power readings of the two devices of between 15 and 20 watts; the Neo reading approx 245 and the Vectors closer to 260. A chart is attached showing hte two rides overlaid on one another.

Is there a problem, or is this normal? I don't know how the different readings are taken, but assume that they should be broadly similar across the range - the variation seems to great to be accounted for by devices at opposite ends of their tolderance ranges to me. Grateful for your thoughts?


Any advice would be gratefully accepted.

  • You heard about Power Match 2.0 Beta on Trainerroad?


    i tried it today and it worked perfectly on my first ride!

  • will try, power match between tacx flux 2 and neo 2t is very different in TR.

  • Soooo, my original post still stands - a significant difference between Vector 3 and Neo 2T power. Yesterday I acquired a second set of Vector 3 pedals and installed them on my bike. At 250w they read about 2w lower than the Neo... This is much more in line with what I originally expected - time to service my original pedals I think...

  • Same here. 7% more power on Assiomas. This is not only annoying but also affecting my workouts. My solution was to set Calibration on Assiomas to -7% to match readings from Neo. Of course, it means all my measurements and PB's got from measurements on Assioma now can be trashed but at least my in-door and out-door trainings are in line.

    Is there any way to calibrate Neo at home?

    Best regards,

  • the Assioma and Neo's power are always different because the Neo's measuring it on rear wheel, the Assioma is at the pedal , and between there is a drivetrain system which has loss 2-4% minimum, depending on the condition of the drivetrain and the used gear . 

    The question is, on which power have You 7% and which gear is used (fixed one in ERG or mixed in SIM mode), because at 150w 7% is 10w which is could be normal on big ring . 

    Do You have 2 FIT files  (with Neo and with Assioma power) or a visual comparison?  , because there could be huge difference between 7% and 7% if we know the circumstances... 

  • Power is power, where is mesuared it doesn't matter. So if there is a loss on the drive train you should calculate and add that "error" or "loss" to your output.

    What you are saying is that garmin is lying on the 1% accuracy. 

    Power is power no matter where is mesuared, all is in the same system.

  • what? :) i think You should learn a little bit physics :) 

    the 1% accuracy stated that the device is always within 1% comparing to ITSELF, so if you pedal a given power that 200w today, 201 tomorrow, 199 2 days later but within 1%, it is called reliability.

    Because the drivetrain loss on bike is not negligible, that is evident if you are measuring somwthing at the crank/pedal, which is 200w that power at the rear wheel is somewhere 190-195w (depending on many factor), if you have 2 powermeters on bike, like a Assioma Duo or V3 pedal based  and a PowerTap G3 rear wheel based powermeter than you will have same 2-4% difference between the 2 values and both powermeters are measuring correctly. The situation is the same at the Neo, it is a "rear wheel" based powermeter and ALWAYS less than a crank/pedal based powermeter and cant be the same (because there is no lossfree drivetrain on the market yet...)

  • Wrong. The 1% is against you. Or the person that is producing the power. The trainer just measure.

  • You are uninformed a bit... try to read more (scientific) articles about the indoor trainers and its operation 

  • Nope i'm not. This must be one of the most hilarious and ridiculous answers i've ever read:

    "the 1% accuracy stated that the device is always within 1% comparing to ITSELF,"

    Thanks for this.