Drafting

[faheyb]

I have noticed during ride downloads the "% drafting" check has become too frequent, following out and back rides, when I am alone.

This can be corrected through the SW with the resulting significant increases for AP, NP, IF, TSS. Following that I have monitored several Group rides, when a significant amount of drafting obviously occurs, but the times that I am at the front increasingly appear as "tail winds" when I am well aware that the wind was mainly ahead to cross winds. In this case drafting was taking place and no reasonably accurate SW correctrion appears possible. ie It appears that the drafting/tail wind effect has been increased above the actual level and my overall ride data compromised.

As I now download to Training Peaks and monitor daily, weekly TSS, downloads may be significantly lower re NP, IF, TSS etc. I would like a fix for this issue.

thanks

Brian

[Velocomp]

This same message happens to me frequently. I ride in South Florida, where strong cross winds are frequent. Isaac software can't detect the difference between strong winds and drafting; that's why the question appears.

If your issue is something else please post a ride file and we will take a look.

[racerfern]

I have noticed during ride downloads the "% drafting" check has become too frequent, following out and back rides, when I am alone.

This can be corrected through the SW with the resulting significant increases for AP, NP, IF, TSS. Following that I have monitored several Group rides, when a significant amount of drafting obviously occurs, but the times that I am at the front increasingly appear as "tail winds" when I am well aware that the wind was mainly ahead to cross winds. In this case drafting was taking place and no reasonably accurate SW correction appears possible. ie It appears that the drafting/tail wind effect has been increased above the actual level and my overall ride data compromised.

Brian,

"ASSUMING" you have a good profile with wind scaling then try un-checking all boxes but check the box that says Enter Known Elevation. Enter your starting and ending elevation and use those numbers. BTW I also have the following checked: Edit > Preferences on the Analysis tab I have the Automatically Analyze Route unchecked.

My Newton+ is properly set up and I don't have any issues with changes TSS from during the ride to after the ride. At worst I will gain or lose just a couple of points because of barometric changes that slightly skew the beginning and ending elevation.

That said, cross winds are damning to say the least. They can be your friend even if they're slightly headwind and they can be your worst enemy at direct cross or slightly tail. There's been a lot of studies on cross winds and even a few posts on this forum. I've adjusted my wind scaling up ever so slightly to give me readings that are more in line with my RPE and I'm satisfied with consistent, accurate results.

Finally, I consider the Analyze Route function as something to "rescue" a ride that got screwed up for whatever reason. I consider the results I view on Newton the actual results. My 2¢.

[faheyb]

Thanks for the feedback. It may be that my profiles (2 bikes) are not perfect, but I feel that at times the power readings are just too low on a ride I frequetly repeat and on downloading I see the question re drafting. Knowing that there was no drafting and that I did an out and back ride. I fix it by setting the overall wind to zero, I usually see quite an increase in AP, NP, IF, TSS etc

I have unchecked the auto analyse route, and will see how the next ride on the same course turns out.

Brian

[racerfern]

You still may want to kick the wind scaling up a notch or do a cal ride and an out/back immediately after. You might find your wind scaling a tad low as it stands now.

If you decide to manually adjust the wind scaling be very gentle with the adjustment. It makes quite a difference. If you want you can post a cal ride here and we can look at it.