Using PowerPod with new TT mount

[Carlos13]

I just received the TT mount and went out to try it. Early morning, the wind was low. Practically zero traffic. An out and back. There are curious artefacts in the data. The wheel speed seems to momentarily drop, similar to what happens if it drops out in a Garmin file, but it doesn't drop to zero. This could be explained if the PowerPod momentarily lost connection to the speed sensor. However, at exactly the same time, there is a spike in the wind speed. See the attached image for a few examples - sudden drops in wheel speed, always accompanied by a similar, but opposing increase in wind speed. Any ideas what might cause this?

Screen Shot 2016-05-28 at 08.48.13.png (241.57 KiB) Viewed 4060 times

[Velocomp]

Please post your .ibr file.

[Carlos13]

Attached, thanks.

[Velocomp]

Your speed sensor is dropping out.

Make sure your speed sensor/magnet are properly positioned.

[Carlos13]

Yes, that much I knew. It's not dropping out on my Garmin though, which is further away from the speed sensor than the PowerPod...

Reading around, I presume this is the reported issue with speed sensor dropouts, i.e. I need to buy a front hub-mounted sensor.

It's interesting that when ground speed drops out, there is a spike in wind speed. That implies that ground speed has some influence on the "measured" wind speed...? (I know wind speed isn't actually measured, but I'm surprised if ground speed is having an influence on the calculated wind speed)

[Velocomp]

It's tough to tell on the Garmin when speed dropouts happen, because GPS data is automatically substituted when sensor data is faulty.

When speed data is intermittent the PP has to "restart" each time speed data is reacquired. The wind sensor operates completely separately from the speed sensor, so any data spikes are not real.

It sounds like the magnet less speed sensor would be a good idea for you.