Quarq calibration help

[BLD 25]

Hey, I have a hollowgram quarq, and recently sourced another used model to put on another bike in the hopes of having matching power on both bikes. The original one has been very consistent, and has worked very well. It tracks closely to a single arm stages that I have on another bike, but reads just a little more conservatively, which is fine.

I downloaded the Quarq Qalvin Legacy program on my PC, which as I understand can updated firmware, etc. It was showing it running the most recent firmware, and showed cadence without a magnet, which as I understand was a more recent firmware edition as well.

The problem is the power reading. It shows power, but it is really really low. Like 5-10X too low. I am 190lbs, and going uphill standing on the pedals, I was showing 49 watts. When I calibrate, the original quarq shows a number in the mid-400s, and this one shows a -mid to high 400s.

Can it be fixed? The program is a bit over my head? Any help is appreciated!

[prototoast]

It should calibrate through your regular bike computer, not Qalvin. Have you tried that?

[kppolich]

https://youtu.be/OYGOBhKT1PE

I dont have an ANT+ stick in the house or else I'd fire mine up and see what the Qualvin legacy app settings has. I know it is possible to see what stress sensors are firing and also set slope.

Edit: Check Diagnostics-> advanced diagnostics to see if there are any stuck switches or broken gauges. Page 4 here:

https://manualzz.com/doc/6458133/qalvin-user-manual

[kramnnim]

Reset the slope. And...it’s probably toast.

[BLD 25]

Reset the slope. And...it’s probably toast.

What makes you say it is toast?

[glepore]

That's not likely a calibration/slope issue. Power meters are actually simple devices that are hard to build. If its reading cadence acurately and the "calibration" (actually a zero offset) is ok, but the power reading is that far off, its likely an issue with the internal electronics or a strain gauge. If you haven't, try the reset outlined on various sites, including sram's, for factory reset by shorting the edge of the battery case against the center contacts with the battery out. It apparently clears the internal memory or something.
I'd call Sram's customer service line. They're pretty good.
The advice to check through the advanced diagnostics is good.
FWIW, I have two older Quarq Elsa's that are dead reliable other than the battery contacts having to be occasionally tweeked, but they have a reputation for not liking the rain a whole lot.

[kramnnim]

What makes you say it is toast?

Had 3 go bad.

[kppolich]

Not a bad idea to do the 'Short' reset, it has also worked for me in the past.

t seems to "reset" the device. Just take out the battery and touch the battery to the two contacts in the battery holder for a second and then reinstall.

https://live.staticflickr.com/7393/9459962467_fc11c59e90.jpg

[BLD 25]

Not a bad idea to do the 'Short' reset, it has also worked for me in the past.

t seems to "reset" the device. Just take out the battery and touch the battery to the two contacts in the battery holder for a second and then reinstall.

https://live.staticflickr.com/7393/9459962467_fc11c59e90.jpg
Thanks! I left the battery out overnight and then did a similar method from the manual which recommends touching pliers to both connections inside and out without a battery. No luck. Was going to redo the slope, but my gram scale only goes up to 5kg, and the app recommends 20kg or more. I think I am screwed.

If course, the seller said it worked for him, suggested a couple things, and has disappeared after those didn't work.

[loxx0050]

Do you have something heavy enough maybe see if your local post office will check the weight for you. They typically have scales that are routinely certified/calibrated. To really guarantee you have 2 different PM's that read consistently to each other is to set the slope with a known/same weight on both of them.

Otherwise if you're willing to spend the money you can buy a certified weight online from Amazon but I'd probably take one of those to the post office to double-check.

[kramnnim]

If it doesn’t need a magnet it should have omnical or whatever they called it and you should not have to adjust the slope.

I can’t remember if you have to set the crank arm length in Qalvin? With two bikes and two devices with Qalvin connected could you check/compare the torque reading with the same weight?

If SD is not on shelter at home maybe you could call them. But if it’s that far off I think it’s dead.