How many MPH do you drop when going against headwind???

[salsabike]

The force that acts against you riding into the wind is proportional to the square of the relative wind velocity. If you are going into a 10 mph wind at 10 mph, the force is K*(10+10)^2 = 400 * K. If you are going 20 mph into a 10 mph wind, the force is K * (10+20) ^ 2 = 900 * K

The multiplier K depends on your frontal area and how aerodynamic you and your bike are, and the viscosity of the fluid you are moving through. It's harder to bike through water.

[mimitabby]

hey Salsabike i love your physics

I have been blown by side gusts that almost knocked me down. (scary!)
Wind is terrifically strong and if it slows you down, you're just obeying the laws of physics. Even Lance can't go as fast into a headwind as he can without!!

[Lifesgreat]

Wind is terrifically strong and if it slows you down, you're just obeying the laws of physics.

I guess I ought to obey SOME laws out there. Oh, I will obey the law of gravity too.

[salsabike]

Yeah, headwinds both ways. That always amazes me. I'm always sure I'll get an equivalent tailwind as a reward for bucking the headwind on the way out, and it just doesn't work like that. But no matter how much I know that, I'm always a little disappointed. On the few occasions when it does happen, though---how much fun is THAT??? Screaming back home at 20+ mph. Love it.

[betagirl]

That happened to me on the 300K. I was all stoked about having a tailwind back. Not.

For the original question, I'm about the same as you with speed. 18-22 on a flat. When I'm going into say a 10mph wind, I drop to around 17. If it's stronger, say 15-20mph, I drop to like 15. So if that's being out of shape, I'm right there with you I do try to get down into the drops when the wind is blowing. I gain a mph or 2 if I do that.

[FreshNewbie]

Thanks for the replies, i guess i am not alone. I thought maybe I am not strong enough. Also, forgot to mention that I have to pull 35lb steel bike so I guess that will make it even worse! would be interesting to see what happens when i will buy myself lighter bike, can't wait.

FN

[ladyjai]

i was out riding this last saturday 3/4 of the way with headwinds, and a fixed gear bike. at one point we finally saw no wind. it was great, our speeds moved up to a comfortable 20, then like a wall, we were hit with the wind all at once. it was like brakes were applied to the bikes, and we dropped 3mph in an instant.

[Geonz]

I've decided that most people who hate wind mainly have trouble dealing with that number on their computer getting smaller, and if they'd get over it, they could have fun in the wind, too. It's better workout per mile, after all! In general, going out too hard at first makes for less fun, and if you're trying to keep the numbers up in the face of a headwind, you're going to do that. I don't mess with the numbers, and just let my body work as hard as it was going to work.
Winds here will take my 17 mph down to 11 or 12 ... sometimes 6 or 7 but then I figure it might pick up a cow and hit me with it...

[SnappyPix]

The force that acts against you riding into the wind is proportional to the square of the relative wind velocity. If you are going into a 10 mph wind at 10 mph, the force is K*(10+10)^2 = 400 * K. If you are going 20 mph into a 10 mph wind, the force is K * (10+20) ^ 2 = 900 * K

The multiplier K depends on your frontal area and how aerodynamic you and your bike are, and the viscosity of the fluid you are moving through. It's harder to bike through water.

I THOUGHT it must be something like that!!!

All you need to know is that the wind is never with you, it's either against you, no wind at all, or you're just having a really good day!
And even if it's against you, stone me if it doesn't change direction, so it's there again on your way back!

[mimitabby]

And even if it's against you, stone me if it doesn't change direction, so it's there again on your way back!

i thought that was a Seattle weather condition. It happens in New Zealand too?