Ground Wind

[philatlondon]

I seem to always get a negative average ground wind. Is this normal?

[racerfern]

Assuming you did a proper wind offset prior to the start of a ride there are a couple of reasons this could happen:

If you ride along with a group as opposed to leading the group you will have negative wind. IOW, you are going faster than the wind is hitting you. In the middle of a group doing 20mph you might only have 10mph of wind so that is -10

If you ride along a road with constant traffic, you can end up with negative wind. And you can have it in both directions if there are no other wind effects.

To confirm your wind find a solitary piece of road. If it is windy out, ride into the wind and note the wind difference as a significant positive number in relation to your bike speed. Then turn around and note the wind difference as a significant negative number in relation to your wind speed. Of course the average of the two sections should be close to zero.

[5am]

I generally ride a straightforward out and back route. Same as you, I tend to get a negative wind number. Only seems to be positive (say in the +.1-4 range) when either the outbound or the inbound run has very strong crosswinds, say in the 15-20 mph range. More often than not in recent weeks, I've just started to make the calculation 0.0 when I do the ride analysis. I'm not sure how accurate that makes the analysis, but I get tired of fighting the wind on a ride only to see the upshot is a negative ground wind figure.

[rruff]

Of course the average of the two sections should be close to zero.

Just wondering what the experiences have been with this... is it really close to zero, or tend to be positive or negative? How about cross winds?