Thread: Wind
View Single Post
Old 06-09-09 | 12:43 PM
  #13  
umd's Avatar
umd
Banned
 
Joined: Sep 2005
Posts: 28,387
Likes: 3
From: Santa Barbara, CA

Bikes: Specialized Tarmac SL2, Specialized Tarmac SL, Giant TCR Composite, Specialized StumpJumper Expert HT

Originally Posted by chadteck
Right, but what I'm saying is this (with really rough numbers):

No wind entire distance: 20 mph average.

Tailwind half distance: 25 mph average.

Headwind half distance: 15 mph average.

Total average: 20 mph.

I understand you will spend more time in the headwind, but you partially made up for that lost time (vs. zero wind) when you had the tailwind. The point I am making is that I underestimated the effect of a constant wind on an out and back course.
But I am saying that *intuitively* you can't think has half the distance. Average speed is total distance / total time. You spend a lot less time going 25mph for half the distance than 15mph for the other half the distance and therefore the average has to be less than the no wind average. That's not taking into account that a 10mph wind doesn't affect each direction equally either...
umd is offline  
Reply