PT data showing high cadence when I'm coasting

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On a recent time trial practice session I felt that my power levels were off because they seemed abnormally high for how I was feeling. I did some searching on this site and found a formula to apply to the raw data in .csv format to try to correct the erroneous data.

I imported the file into excel to look for non-zero torque levels while coasting. I knew the points on the ride when I coasted because after the time trial effort I was watching my wattage while coasting to make sure it wasn't going to zero like it should. It was actually coming down slowly towards zero as my speed dropped, but wouldn't hit zero until I stopped.

However the points on the data where I know i was coasting say that my cadence was somewhere in the 120 to 150 rpm range. When I started to pedal again, it looked fine. My torque during the periods of these high cadence levels was .6 to 1, indicating that it was not zeroed, even though I zeroed it before the ride. I use the hub only for cadence and don't have the wired sensor. I don't watch cadence while I ride, so I don't know what it was showing on the read out of the computer at the time.

Two questions- can torque go out like that during a ride, even though it was calibrated beforehand (and why)? And has anyone else noticed wacky cadence #'s like this and could it indicate some kind of problem?

thanks

http://www.cyclingforums.com/t352638.html

TF

I saw that post, which was useful to me. But when I import that data it shows a high cadence when I'm coasting. I'm wondering if this is indicative of a different problem. It's saying my cadence is 120+ when I'm coasting.

I saw that post, which was useful to me. But when I import that data it shows a high cadence when I'm coasting. I'm wondering if this is indicative of a different problem. It's saying my cadence is 120+ when I'm coasting.It looks as if you need to zero the computer. If you have done so already, and you are still having issues, a call to Saris is in order...

I had one of the first batches of SLs and I started having an issue with the PT needing to be zero'ed several times during a ride. I had to return the unit to Saris for repair. It has been fine for over a year...

Jim