Vector 3 accuracy thread

So here we go... This is the accuracy thread for the V3.

Now for my first post here, I need to inform you, that my comparison is with a Kettler Ergoracer S (2016 model). Note this bike has a flywheel which resistance is being controlled electronic. The bike is calibrated according to a DIN std. and the bikes comes along with the calibration sheet. My bike is slightly below actual wattage. As a simpel test, I do get the same result when doing a FTP test either on Kettler or outside with a different powermeter. So the wattage must be about right.

Back when I had Vector 2, one funny thing, I had to set the pedalarm to 187 mm (actual is 170 mm) to get the same wattage as Kettler(!). Never the less is worked quite well. With that setting I got good comparable data from both sources. So when getting V3 in my hands, I started out setting the pedalarm length to 187 mm. Once done riding, I compared the data. To my surprise and happiness, I found that V3 had to be adjusted to 171 mm to perfectly aligned with Kettler. Sweet thing - so I adjusted to 170 mm. However on the following ride, V3 was clearly not showing enough(?!). Going through the same comparison, I calculated the adjusted pedalarm to now 198 mm...!?!

So my very first conclusion here, based on only two rides indoor on my Kettler with V3 is the following. To get aligned wattage, I see pedalarm length varies from 170 to 198 mm. That's a difference about 16%

Check out the charts below and let me hear your thought...

EDIT: can't upload my second picture. I'm gonna try again later...
ciq.forums.garmin.com/.../1280575.png
  • Former Member
    0 Former Member over 7 years ago
    I think most of the inconsistency happens when you are in ERG mode with a higher cadence 90+ or more.
  • Here is a comparison between my Vector 3 and Tacx Neo.
    One thing I think is a bit strange is that it is not like one is alway higher than the other, sometimes it's the Neo that measures highest, and sometimes the Vectors.

    I don't actually know what I can reasonably expect, is this good accuracy or...?

    I note that the average power is 12 watt off, but the weighted power is nearly identical.

    https://analyze.dcrainmaker.com/#/public/c18da67d-b036-4b2f-7ae9-ac2045bef10c



    I had a quick look at your data. For the most part it is visually an excellent match

    The big difference comes where there is a dropout of your power at the beginning and the end of the file. If you select from 2 minutes to 50 minutes in the file the average is 234 vs 230. This is ~2% difference which is basically the quoted accuracy of both systems.

    So looks pretty good!
  • Former Member
    0 Former Member over 7 years ago
    I got a new Cycleops Hammer and did my first comparison with the V3 and I am happy to report that there's only 1% to <1% difference in the averaged power!
    I know the hammer does temperature compensation as the V3s. In addition this is in ERG mode also.
  • RE: Replacement pedals.

    Posted this in another thread and thought I should share here as well.

    Exact same experience here...

    Replacement setup/configured without issue. Booted up my edge/forerunner and quickly connected... Things were looking good... Within the first few minutes it disconnected and never reconnected after that... Since then I've recorded 4 additional rides and only once did the pedals stay connected more than 90% of the time... Constant drops and spikes throughout each ride... Like others, seeing spikes upwards of 2500 watts.

    Was very reelected to open battery casing, but did so, and replaced batteries, but still same issue.

    Incredibly frustrating.