Headwind effect

stu-bim · March 2013

Is there any way to measure the effect headwind has speed, apart from the obvious in difference in time.

Just cycled to work with (according to accuweather) 22mph headwind. Kinda inclined to believe it as I checked it because it really hurt and time was slow. Always have headwind in and tailwind home so it'll be there for going home so not complaining (well maybe). But home is usually 5 mins slower than in because of incline but this morning I was slower in than home last night but didn't lie that.

meanredspider · March 2013

Speed is a function of time (and distance) so the two are linked. The effect will also show up in power but that's also a function of speed and, hence, time. So, honestly, time difference is a key measure (unless you have a power meter in which case you'll have a good indication of how much additional energy you've used)

rolf_f · March 2013

Once you've done the route enough, it will be pretty obvious what the wind effect is. Currently, my uphill commute home is taking much the same time as my downhill commute in due to the nasty Easterlies. Infact, one return trip this week differed in time by 1 second! You pick up also at certain places where you reach certain specific speeds depending on condition.

Incidentally, unless you are getting direct head and tail winds and your tail wind is on the uphill leg, then overall you'll tend to lose on windy days rather than calm ones. The loss due to the headwind is normally less than the gain due to the tailwind.

SteppenHerring · March 2013

It's difficult to quantify. Position on the bike has a big effect also flappy clothing.

A while back I did a 100 mile TT on the H88 course which is 10 miles South West, 10 miles North East x 5. It was a windy day (as it always seems to be on that course). Looking at Garmin afterwards I could see the SW leg was taking me 10 minutes longer than the NE leg, despite a lower HR on the NE leg. I also learned that 100 mile TTs are hard and it's possible to get very sticky consuming energy products on the move.

The loss is always more than the gain. Imagine that you can ride a 10 mile TT at 20mph (to make the maths easy) so that would be 30 minutes. If you've got a headwind on the out leg that gives you -10mph out and +10mph back, then by the time you've reached the turn, you're already at 30 minutes (5 miles @ 10mph).

Headwind effect

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