Tempe Sensor - real world use for Garmin Edge

I see the Tempe sensor is supported in the newest beta for Edge 1040.  I'd always assumed that there would be no need to have a sensor "out of the sun" since my body is taking in sunlight anyway.  Maybe I'm thinking about it wrong.  However I just noticed that sitting in my 73 degree room, the 1040 is currently reading 80 degrees.  

Can anyone that has used a tempe with other devices comment on how useful it would actually be in terms of the Garmin Edge readouts for "adapting" for training, and all that stuff?  If it's useful I don't mind picking one up.  I'm just not sure on the usefulness.

Also - unsure if it would be best to leave the tempe sensor in the sun, or tuck it away under the saddle.

  • What happens if you record a activity/ride with the phone disconnected (ie. the Edge has no weather data for that ride at the time of recording)? Is this something that is added and processed on sync with Connect, and/or done on the device itself?

  • It would be interesting to hear of some real-world experience. Like you say, on the wrist is always way out (body heat etc) but I always assumed an Edge in the wind would record fairly accurately (cooling wind countering direct sun, at least to a degree).

  • Cycling speed and thus cooling breeze helps to reduce the heating of the Edge in the sunshine as climbing a significant hill where speed is reduced results in a noticeable rise in the Edge's temperature. I've got a Tempe sensor mounted under the stem where is is fairly well shaded from the sun (but not radiation from the road surface) and I'm using Tempe Visualizer to log the Tempe data to the .fit file (and also using a -2C temperature correction) and this graph from this morning (starting 07:30) shows what each device reports.

    At around 16 minutes into the ride when it was still fairly cool and the device temperatures had stabilised (the Edge had been in the house, the Tempe on the bike in a cooler garage) the two devices were in close agreement  (Edge 17C, Tempe 16.96C). At 1:10 in the ride with the sun stronger and on my back and near the end of a gradual hill the Edge was up to 26C and the Tempe was 23.23C. I then turned a corner onto a flatter and shaded section of road  and the temperatures dropped although the Edge was still more than 1.5C. At the end of the ride the Edge said 24C and the Tempe 22.2C while the Davis Vantage Vue weather station in my garden recorded 22.5C.

  • Depends a bit on its construction, but usually a road-bike saddle is thin enough to get heated by your body.

    Bottom of the bottle cage that’s on the seat tube is where I have mine for measuring air temperature.