Humidity affect on biking speed

mary said:

On a day with a high humidity (everything else being equal) would it take
more energy to bike a certain distance than on a day with low humidity since
a person has more resistance from the moisture.

Water vapor is less dense than dry air. A more humid air mass
is less dense than a dry air mass. Not only that, but since
your hair is all matted down from sweat, you present less
surface area!

So you should be rocketing along on those humid days!

Scott

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

On a day with a high humidity (everything else being equal) would it take
more energy to bike a certain distance than on a day with low humidity since
a person has more resistance from the moisture.

Thanks

Water vapor is *less* dense than air (molecular weight 18, vs Nitrogen
at 28 and Oxygen at 32), so the air resistance would likely be less on a
humid day. This causes big problems for propeller-powered airplanes in
the tropics if they aren't equipped for it.

--
Remove the ns_ from if replying by e-mail (but keep posts in the
newsgroups if possible).

On Tue, 13 Jul 2004 10:02:01 -0500, Scott <[email hidden]>

Quoted message said:

mary said:

On a day with a high humidity (everything else being equal) would it
take
more energy to bike a certain distance than on a day with low humidity
since
a person has more resistance from the moisture.

Water vapor is less dense than dry air. A more humid air mass
is less dense than a dry air mass. Not only that, but since
your hair is all matted down from sweat, you present less
surface area!

So you should be rocketing along on those humid days!

Scott

Unless it's hot and humid, then your cooling mechanism, sweating, doesn't
work as well. If you get hot, you could overheat.

--
Bob in CT
Remove ".x" to reply

Also, hot air is less dense. Convert temperature to Celcius (-32 * 5/9)
add 273 to convert to Kelvin. Take 273 and divide by the Kelvin
tempature to get this ratio. EG 30 Celcius (86 Ferenheit) has a ratio
of 273/373 dry air density (0% humidity). Also, warmer air can hold
more water vapor as tempature rised. A dew point of 65 degree Farenheit
means the air, if cooled to 65 F, would be at 100%. Warm the air to 90
with that days sun and the humidity is 60% with the same amount of
moisture in it. Take it to 212 F 100 C and 100% humidty means 100%
water vapor, 0% nitrogen, 0% oxygen. There are water vapor tables that
can tell you at what tempatures 100% humidity means as far as percent
water and percentage air.

David Kerber said:

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

On a day with a high humidity (everything else being equal) would it take
more energy to bike a certain distance than on a day with low humidity since
a person has more resistance from the moisture.

Thanks

Water vapor is *less* dense than air (molecular weight 18, vs Nitrogen
at 28 and Oxygen at 32), so the air resistance would likely be less on a
humid day. This causes big problems for propeller-powered airplanes in
the tropics if they aren't equipped for it.

--
Remove the ns_ from if replying by e-mail (but keep posts in the
newsgroups if possible).

Putting the science aside, I love riding in hot humid weather. I feel cool
when riding because of the air flow around me. I like it when I look down
at the water bottles and have sweat drip off my chin. When I roll up to a
stop sign is like walking in to an oven. My arm and leg instantly get wet
with sweat. It makes me feel really strong. ( ha ha)

Yesterday it was around 90 deg F and very humid in Oshkosh and I rode 51
miles. I drank about twice as much as I usually do, about two water bottles
an hour.

"mary" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On a day with a high humidity (everything else being equal) would it take
more energy to bike a certain distance than on a day with low humidity

since

Quoted message said:

a person has more resistance from the moisture.

Thanks

Tom

Monty said:

Yesterday it was around 90 deg F and very humid in Oshkosh and I rode 51
miles. I drank about twice as much as I usually do, about two water bottles
an hour.

Make sure you're getting plenty of electrolytes. Drinking two
bottles of plain water is a recipe for hyponatremia, whihc is not
pleasant.
--
terry morse Palo Alto, CA http://bike.terrymorse.com/