Garmin 910xt - Spontainious change in power calibration value
Question for Garmin 910xt owners who own a power meter.
Back Story: So I was doing my bike race rehearsal today using my SRM power meter and 910xt at which point the power dropped to zero for no apparent reason. Stopped to see what the problem was and my first thought is always to check the positioning of the magnet which I found was knocked out of alignment. Made the adjustment and started to go again with still no power.. Stopped.. made another adjustment.. Still no power. Stopped a third time and check the calibration, which I found had a calibration value of about 1100. When I started the ride I calibrated and the value calibrated at 564. (I'm 100% positive on this). Re-calibrated (about 564 again) and started riding again and all was fine at this point. About half an hour to an hour later.. The power dropped to zero again with no beep or anything obvious to cause it the drop so I checked the calibration again and the value was high again at about 1050.. Re-calibrated and didn't have a problem for the remainder of the ride.
I plan on calling Garmin and reporting this in case they have seen it before. I'm on Firmware Version 2.8 (3.0 just published the other day). I'm sure Garmin will tell me to upgrade to 3.0 but I'm leery of this as it was just released.
Has anyone seen the calibration value spontaneously change to a high value (maybe double) in the middle of a ride causing the need to re-calibrate?
Thanks!
Comments
I am experienceing power reading drop outs between my 910xt and powertap hub. I called both garmin and powertap. Garmin said my wrist might be too far away from the hub (I laughed).
Powertap said to try calibrating, checking the value and if it was very high or very low to call them. They said to expect 500 to 525 or so. So I will be doing that on my next ride.
I am on firmware 3.0 btw.
what did Powertap say? on other sites people report they have been told to remove the battery, wait a few seconds then replace the battery to reset the power tap. A similar problem happened to me once before an outseason workout. Taking out the battery and putting in a new one problem for me and it has never happened again . Knowing what I know now, maybe just putting the same battery in would have been ok (it wasn't old). Another thing, I have only experienced powertap problems with Sony Lithium batteries I bought in bulk for 2$ a piece, never with Energizer batteries from the store at 5$. I think these devices are very susceptible to even small variations in voltage that might occur with an older or lower quality battery.