Is this ground wind analysis correct?

[mooneyrider]

I did a ride on a pace line today and when I did the Analyze Route today, Isaac calculated an average ground wind speed of -8.9 mph. I did tick the "Drafting In This Ride" box. Since this was a very early morning ride, I know there was no ground wind to speak of.

A screenshot of the Analyze Wind dialog result is attached. As far as I can tell, the wind speed went to zero either when I was on the front of the pace line or when we were climbing and there was no aero shelter to speak of from other riders.

Is this the correct outcome for the Route Analysis or Wind Analysis that I should expect for such a ride? Or should I be changing the average wind speed offset to correct for this?

Thanks, David

[Russ]

Hi moneyrider,

I usually only ride with one or two other guys and so not a long paceline but the numbers look reasonable to me. In particular look at the times the 'ground wind' goes near zero. If you were pulling at the head of the line at those times then bingo.

The appearance of negative ground wind is normally a direct result of drafting. Effectively there is no difference between a tail wind and drafting. The iBike does not have a camera

Russ

[mooneyrider]

Russ:

Thanks for the clarification. That makes sense to me that the drafting portion are like a tailwind. Just wanted to understand the calculations better.

Cheers, David