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-   -   Quarq SRAM s975 Stopped Functioning (

mkadam68 09-04-13 02:33 PM

Quarq SRAM s975 Stopped Functioning
About 6mos ago, picked up a used power meter. Works awesome, ride any wheels I like, etc...

I replaced the large chainring with a SRAM 55t ring for training purposes. Then, about 1mo. ago, it stopped working. Garmin 500 apparently receives no signal whatsoever. I've tried my son's Edge 500 that picks up the signal from his PowerTap, and it doesn't work either.

I'm wondering if the magnet for the s975 has fallen off my frame (appears that way as I cannot see one). Either I knocked it off accidentally or maybe during a crash. Would that prevent the power meter from sending a signal? I thought they were only for calculating cadence and not directly measuring power output. Anyone confirm?

Cleave 09-04-13 03:22 PM

Hi, I know that my SRM will not send a signal without a "cadence" magnet. The SRM turns off after some period of time if it does not sense the magnet. I am hypothesizing that the Quarq works the same way.

AzTallRider 09-04-13 04:24 PM

Yes, the Quarq will give you nothing without the cadence magnet - it won't even turn on. With that Quarq, the magnets are either glued to the frame, typically right behind the BB, or for an external BB, it's attached to a flat ring that goes under the BB cup. If you see nothing, it was probably glued on and fell off. Use good epoxy paste and glue one on. You can download the manual to get instructions.

mkadam68 09-04-13 04:47 PM

Thanx. Will look into it.

shovelhd 09-06-13 06:10 PM

Power = torque times rpm. The power meter measures torque. Without cadence, it cannot calculate power.

That said, I had two S975 power meters go bad on me. The last one was replaced under warranty with a Riken. It is a much better unit and has proven to be consistent.

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