Isaac detects drafting when no actual drafting

Post Reply
GeorgeHotopan
Posts: 40
Joined: Wed Feb 11, 2015 5:02 am
Location: Stuttgart, Germany
Contact:

Isaac detects drafting when no actual drafting

Post by GeorgeHotopan » Wed Apr 29, 2015 5:26 pm

Hello everyone:

I believe this topic was somehow discussed in other threads, but just to make sure I attach a ride file I did today and explain myself.

It is a solo ride, NOT out-and-back, but it ended where it began. The original file (if analyze and return to original option is used) marks an average power of about 136W if drafting is checked, as the Isaac pop-up window suggests. Nevertheless, comparing this ride with other rides I did on the same course, the wattage is about 30W lower than expected. If I uncheck drafting box, then average power jumps to a more reasonable figure of 164W.

Could anyone double check the file and confirm that I should uncheck the drafting box. Why does Isaac believe I was drafting when I actually wasn't? Waiting for valuable feedbacks!

Best regards,

George.
Attachments
iBike_04_29_2015_1734_32_km.ibr
(430.61 KiB) Downloaded 68 times

User avatar
racerfern
Posts: 1356
Joined: Fri Jan 11, 2008 1:47 am
Location: Baldwin, NY
Contact:

Re: Isaac detects drafting when no actual drafting

Post by racerfern » Wed Apr 29, 2015 8:17 pm

If Isaac sees a period of time with a substantial tailwind it will assume you drafted.

I personally have no boxes checked and I enter my own starting and ending elevation. The results are absolutely consistent and repeatable.
Fernando

GeorgeHotopan
Posts: 40
Joined: Wed Feb 11, 2015 5:02 am
Location: Stuttgart, Germany
Contact:

Re: Isaac detects drafting when no actual drafting

Post by GeorgeHotopan » Thu Apr 30, 2015 4:04 am

Thanks for the explanation Fernando! Your feedback is always welcomed ;)

Post Reply