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Discussion Starter · #1 ·
I 'm considering of getting a Quarq PM, but still not sure about calibration. My friend who is using SRM found a way to calibrate it himself with adding weight to calibrate the stain guage. I found that Quarq also able to do that but can't find the device to set it. Found some forum talking about doing through ANT+ divice for PC and a software, can this be confirmed. Also, how and where to get it.
 

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I use a Quarq with an Edge 500. In general use, all that's required is to zero the offset by spinning the pedals backwards. You can also do this manually using the Edge. I believe that if the unit has to be recalibrated, say after changing chainrings, you need to send it to the factory.
 

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giro said:
I 'm considering of getting a Quarq PM, but still not sure about calibration. My friend who is using SRM found a way to calibrate it himself with adding weight to calibrate the stain guage. I found that Quarq also able to do that but can't find the device to set it. Found some forum talking about doing through ANT+ divice for PC and a software, can this be confirmed. Also, how and where to get it.
I own a Quarq and a Garmin Edge 500. I manually calibrate mine through the Garmin Unit before every ride. It takes about 1 minute. I haven't had a single problem in 6 months. I highly recommend the Quarq.
 

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Discussion Starter · #4 ·
How 's the strain guage calibration? Since SRM is the only one PM that can be calibrated the strain guage, for weather, crank replacement, etc, I really want to wait until I can spend for it. But I found on the Cinqo site about strain guage calibration also done by a very similar methods of SRM(adding known weight to the arm) I 'm so curious how to doing. If we 're able to set the calibration ourself, Cinqo will be a very good PM.

The zero calibration is pretty easy as it is 4 revolutions backward spin, but in the long use, we need to be able to set the strain guage of the PM. Unbelievable, my friend using SRM for less than a year, he just calibrated the strain guage and found that it give 1% wrong power might caused by weather, temperature or simething else. Then, he is now happy to do it every 3 months. He said it 's kind a fuzzy at the first time but after couple times, you will love how SRM works as a wonderful engineering tools which able to calibrated.

So curious, how Quarq can 't do this.
 

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the_gormandizer said:
I use a Quarq with an Edge 500. In general use, all that's required is to zero the offset by spinning the pedals backwards. You can also do this manually using the Edge.
That is not a calibration (despite what they might call it). That's simply setting the torque zero. Which means that when you are applying no force, the meter will read zero watts.

However that doesn't tell you if the meter is reading correctly when force is applied and the cranks are moving.

Calibration is a validation that the meter reads correctly when a known force/torque is applied.

You can check it on a Quarq (and a Powertap) but not set it (like you can with an SRM).

the_gormandizer said:
I believe that if the unit has to be recalibrated, say after changing chainrings, you need to send it to the factory.
At the moment that's correct.

Now there is a chance of being able to set it yourself in the future although the process isn't exactly user friendly as yet.

Search for posts by Tom Anhalt on either Slowtwitch or wattage forums as he's come up with a method.
 
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