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how to perform a manual zero - joule

rah2774rah2774
in General Training Discussions

I'm sorry if this is in the forums, I didn't see anything offhand after a little bit or searching.

I'm new to the Q/J set up and did my first test this week.  Following advice, i tried to manual zero pre-test, following the joule instructons re: how to do it.  going to the "manual zero" menu under sensors, etc.  Per the instruction, I checked and noticed that "raw value" and "offset value" did not match.   Per the guide, I need to perform a manual zero - but when I pressed and released the joystick nothing happened.  

Not sure what I should check or do.  When I turn the joule on and am sitting on, not pedaling, the watts don't read (display shows ---).  i didn't set the joule up, the LBS did.  I'm assuming they got the right wheel circumference - would/could this be the issue?  I'd like to check, but I don't know the circumference of my wheel (mavic open pro  650O

anyway, appreciate your thoughts re performing a manual zero as I know this is something we should check and do from time to time.

thanks

Comments

  • TerryOTerryO
    My manual zero has never worked. I zero the Quarq by pedaling backwards like 8-10 times. The joule will not read unless the wheel is spinning when it's set for speed sensor activation.
  • manconamancona
    I don't have a joule, but there is a beta firmware update being tested right now that fixes this issue and allows a manual zero with a quarq or SRM. Jesse from Saris has offered to provide it to anyone that wants for testing on both slowtwitch and the wattage group if you want more information.

    As Terry said you will be ok just back pedaling at least 4 revolutions as that will auto zero it. The advantage to doing a manual zero is you can compare the offset at different points during a right or check the slope (if you have a weight to hang from the crank). Both are for troubleshooting and not really required.

    Unless you enjoy beta testing stuff, I would just do the back pedaling method for now and upgrade the firmware after it is released to the public.

    For your test, just do your warm up and make sure to stop and back pedal before starting the test.
  • rah2774rah2774
    thanks
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