New Favero Assiomas under-reading, help!

Jackofallgrades
Jackofallgrades Posts: 44
edited June 2019 in Workshop
Hi all, I’ve just purchased a set of Assioma Duos and installed them. They’re currently reading about 10% lower than my Tacx Flux S, running the two together, when if anything they should be higher. I’ve been through the steps I can find in the manual etc, making sure the installation is correct, pods aren’t fouling, calibrated after a few hard sprints, calibrated the Flux, checked L/R balance isn’t abnormal, correct crank length plugged in, checked latest firmware (3.00) is in there, and nada. The next step I can find is a static weight test, but I’m not equipped for that at home.

Does anyone have any suggestions or similar experiences they managed to solve? Do I simply need to wait more than one ride, even with sprints, for them to settle in?

Appreciate the help in advance :)

Comments

  • Have you considered the possibility they’re telling you the truth?
  • Well, either they are or my Tacx is, but it’s unusual for a pedal PM to read lower than a turbo that’s all the way behind the drive train. Maybe I wasn’t clear, I ran the pedals on the turbo to compare the two.
  • timothyw
    timothyw Posts: 2,482
    You could borrow a third power meter (perhaps crank based) to try to ascertain which of the two units is the accurate one.

    Right now it is just as likely the Tacx is over-reading.

    The other possibility is you could ride the Favero's up a steep hill at a steady pace and compare the numbers against a power calculation based on your weight etc, although it's hard to calculate this data accurately anyway.
  • jgsi
    jgsi Posts: 5,062
    Is the Flux a strain gauge based power meter?
  • I’ll see if I can find one Tim, there’s a watt bike at my local gym I could potentially try.

    JGSI, to be honest I don’t know!

    The reason I’ve trusted the Tacx til now is I know my FTP from having it tested elsewhere, and it matched up pretty well on the Tacx.
  • timothyw
    timothyw Posts: 2,482
    Yeah, if you could fit the power pedals on the wattbike that'd be a good third meter to compare against - if they read low against that too, then might be time to send them for calibration/return for a new set.
  • hdow
    hdow Posts: 184
    My Tacx read higher than my Vector 1 and now Vector 2 pedals. Wasn't that surprised as many have commented on how inaccurate many turbos are. If your Assiomas are reliable and produce consistent results just use them for measuring power then you will be consistent in and out door. Isn't it about time you did another FTP test? You may also find a difference between in and out door FTP results.
  • hdow
    hdow Posts: 184
    My Tacx read higher than my Vector 1 and now Vector 2 pedals. Wasn't that surprised as many have commented on how inaccurate many turbos are. If your Assiomas are reliable and produce consistent results just use them for measuring power then you will be consistent in and out door. Isn't it about time you did another FTP test? You may also find a difference between in and out door FTP results.
  • Hdow wrote:
    My Tacx read higher than my Vector 1 and now Vector 2 pedals. Wasn't that surprised as many have commented on how inaccurate many turbos are. If your Assiomas are reliable and produce consistent results just use them for measuring power then you will be consistent in and out door. Isn't it about time you did another FTP test? You may also find a difference between in and out door FTP results.

    Yes having done a bit more digging it seems a problem that many have seen, it would be nice to do the static weight test for complete clarity but you’re probably right, guess my ego will just have to take the hit on the turbo :roll:
  • N0bodyOfTheGoat
    N0bodyOfTheGoat Posts: 5,845
    IIRC, Flux power meter typically boosts figures by ~10%.
    ================
    2020 Voodoo Marasa
    2017 Cube Attain GTC Pro Disc 2016
    2016 Voodoo Wazoo
  • Alejandrosdog
    Alejandrosdog Posts: 1,975
    IIRC, Flux power meter typically boosts figures by ~10%.
    I could do with a bit of that then :)
  • MiddleRinger
    MiddleRinger Posts: 678
    I'd put money on it being the Flux over-reading rather than the Assiomas under-reading.
  • jgsi
    jgsi Posts: 5,062
    So now we almost concur that turbo based power is garbage in garbage out, Zwift heroes need to apply for that free counselling after they do their first proper road race and get spat out despite protestations that their power to weight meant that they were "genuine" a riders who can hold 5 w/kg for an hour.
  • daniel_b
    daniel_b Posts: 11,584
    Didn't realise the flux was meant to be that far out, I know my wheel on Vortex definitely does overread by circa 10%.

    Pretty sure the likes of the Neo, Drivo, kickr are meant to be brutally accurate though.
    Felt F70 05 (Turbo)
    Marin Palisades Trail 91 and 06
    Scott CR1 SL 12
    Cannondale Synapse Adventure 15 & 16 Di2
    Scott Foil 18
  • zeee
    zeee Posts: 103
    My flux reads fairly consistent with my powertap Pedals. I'd say within 2-3%.
  • gethinceri
    gethinceri Posts: 1,517
    My Flux reads low, by about 10%
  • I think the most definitive way to answer this will be to put the Assiomas on the Wattbike and see how they compare to that. If they are more than 3% different in power readings I would consider returning them under warranty for a replacement pair.
    I sell most of the products mentioned in this thread and so far have found the Assiomas to be very reliable. I cannot say the same for Tacx trainers however as they have been very unreliable as have Garmin Vector pedals and Powertap pedals. We did a comparison between Assiomas and a Wahoo Kickr and found they were within 1-2 watts of each other so very accurate.
    I would suspect that you Tacx is possibly over-reading but try the Wattbike test to be sure.
    Hope this all helps.
    Graham
  • I think the most definitive way to answer this will be to put the Assiomas on the Wattbike and see how they compare to that. If they are more than 3% different in power readings I would consider returning them under warranty for a replacement pair.
    I sell most of the products mentioned in this thread and so far have found the Assiomas to be very reliable. I cannot say the same for Tacx trainers however as they have been very unreliable as have Garmin Vector pedals and Powertap pedals. We did a comparison between Assiomas and a Wahoo Kickr and found they were within 1-2 watts of each other so very accurate.
    I would suspect that you Tacx is possibly over-reading but try the Wattbike test to be sure.
    Hope this all helps.
    Graham

    Thanks everyone. I haven’t had the chance to do this yet but agree it’s probably the only way to do it. Having said that, the Assiomas have been flawless in every other respect.
  • chris_bass
    chris_bass Posts: 4,913
    have you calibrated everything properly?

    I have the assimoas as well as Elite drivo, tacx fulx and tacx neo (i like tech!)

    the pedals match the drivo and neo within a watt or two.

    they are usually about 5 to 10 watts off the flux regardless of the actual watts i'm doing. i'm no powerhouse though it must be said so not pushing things too much!

    make sure you zero offset the pedals before riding, warm the turbo up with 10 minutes of riding, then do a spin down on the turbo and zero offset the pedals again and see if they are any nearer to each other.
    www.conjunctivitis.com - a site for sore eyes