Wind Resistance, Clothing, & Low-Hanging Fruit?

"(PeteCresswell)" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Since it's gotten little cooler here in Southeastern Pennsylvania,
I've been
doing the occasional ride in cargo pants and a long-sleeved
windbreaker instead
of cycling shorts and a close-fitting shirt.

On the way to where I ride, there's one little macadam
uphill/downhill/uphill
where I crest the first hill at almost exactly 20 mph and, top
pedaling, and
then see how far I can coast up the following hill.

On windless days the diff between high-volume MTB tires and 1.25"
slicks has
been pretty consistent.

A couple of days now, I've tried it with the MTB tires and cargo
pants/windbreaker. The diff between MTB tires/shorts/shirt and MTB
tires/cargo
pangs/windbreaker seems tb even greater than the diff between MTB
tires and
slicks. So far it also seems to take a good 2 mph off of my
cruising speed on
a particular 3-mile stretch - but that's awfully
subjective/condition-dependent...

Anybody else tried something like this?

Could the wind resistance of clothing really be a bigger factor than
the diff
between fat and skinny tires?

Air density. On cold days when more clothing is required, air density is
increased so you get a double whammy. The ratio of air density at 30 deg
C and 0 deg C (constant pressure) is 303/273 = 1.11. If you coast at 30
mph in a toasty 30 degrees, this will reduce to 27 mph at a chilly 0
degrees. IMO this is a bigger factor than the additional clothes.

Phil H

Since it's gotten little cooler here in Southeastern Pennsylvania, I've been
doing the occasional ride in cargo pants and a long-sleeved windbreaker instead
of cycling shorts and a close-fitting shirt.

On the way to where I ride, there's one little macadam uphill/downhill/uphill
where I crest the first hill at almost exactly 20 mph and, top pedaling, and
then see how far I can coast up the following hill.

On windless days the diff between high-volume MTB tires and 1.25" slicks has
been pretty consistent.

A couple of days now, I've tried it with the MTB tires and cargo
pants/windbreaker. The diff between MTB tires/shorts/shirt and MTB tires/cargo
pangs/windbreaker seems tb even greater than the diff between MTB tires and
slicks. So far it also seems to take a good 2 mph off of my cruising speed on
a particular 3-mile stretch - but that's awfully
subjective/condition-dependent...

Anybody else tried something like this?

Could the wind resistance of clothing really be a bigger factor than the diff
between fat and skinny tires?
--
PeteCresswell

Phil Holman said:

Air density. On cold days when more clothing is required, air
density is increased so you get a double whammy. The ratio of air
density at 30 deg C and 0 deg C (constant pressure) is 303/273 =
1.11. If you coast at 30 mph in a toasty 30 degrees, this will
reduce to 27 mph at a chilly 0 degrees. IMO this is a bigger factor
than the additional clothes.

Yes but that effect is smaller than the aerodynamic drag of your chain
and higher humidity could easily counter that, moist air being lighter
than dry air. Let's not quibble about iotas. Adding an inch all
around a rider's torso is significant, especially if it flaps in the
breeze, whap, whap, whap.

Jobst Brandt

"(PeteCresswell)" <[email hidden]> wrote in message

Quoted message said:

Quoted message said:

Could the wind resistance of clothing really be a bigger factor than
the diff
between fat and skinny tires?

Yes... easily.

Phil Holman said:

Air density. On cold days when more clothing is required, air density is
increased so you get a double whammy. The ratio of air density at 30 deg
C and 0 deg C (constant pressure) is 303/273 = 1.11. If you coast at 30
mph in a toasty 30 degrees, this will reduce to 27 mph at a chilly 0
degrees. IMO this is a bigger factor than the additional clothes.

The speed difference will be proportional to the square root of the
density ratio... or in this case 1.11^.5 or 1.054. Floppy clothes could
have a much larger effect. Also, the rolling resistance of tires
increases at low temperatures, which would probably make the difference
between the tires more pronounced.

"(PeteCresswell)" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Since it's gotten little cooler here in Southeastern Pennsylvania, I've

been

Quoted message said:

doing the occasional ride in cargo pants and a long-sleeved windbreaker

instead

Quoted message said:

of cycling shorts and a close-fitting shirt.

On the way to where I ride, there's one little macadam

uphill/downhill/uphill

Quoted message said:

where I crest the first hill at almost exactly 20 mph and, top pedaling,

and

Quoted message said:

then see how far I can coast up the following hill.

On windless days the diff between high-volume MTB tires and 1.25" slicks

has

Quoted message said:

been pretty consistent.

A couple of days now, I've tried it with the MTB tires and cargo
pants/windbreaker. The diff between MTB tires/shorts/shirt and MTB

tires/cargo

Quoted message said:

pangs/windbreaker seems tb even greater than the diff between MTB tires

and

Quoted message said:

slicks. So far it also seems to take a good 2 mph off of my cruising

speed on

Quoted message said:

a particular 3-mile stretch - but that's awfully
subjective/condition-dependent...

Anybody else tried something like this?

Could the wind resistance of clothing really be a bigger factor than the

diff

Quoted message said:

between fat and skinny tires?

Yes. I saw once a televison program where they measured the difference in
windresistance between sloppy clothes en tight fit clothes in a windtunnel.
I can't remembered the figures but I was very surprised of the difference.
Since then I make sure my cycling clothes are tight fit. Even my
winterclothes. No flapping clothes for me anymore.

Lou

Quoted message said:

--

Quoted message said:

PeteCresswell

Lou Holtman said:

Yes. I saw once a television program where they measured the
difference in wind resistance between sloppy clothes en tight fit
clothes in a wind tunnel. I can't remembered the figures but I was
very surprised of the difference. Since then I make sure my cycling
clothes are tight fit. Even my winter clothes. No flapping clothes
for me anymore.

There is a much more important feature of fitting clothes for me
because the cold I run into is in the Alps in the summer (where it can
snow any day of the year!) If the jacket flaps it isn't warm because
there is a bucket brigade of oscillating air carrying the heat from
the body to the outdoors. You'll be surprised when descending in the
cold how much warmer it gets immediately, when you suppress the
flapping. This is a descending problem but...

The stupid thing is bicycle clothing manufacturers don't know this and
keep selling flapable wind breakers with all sorts of vents. CUT IT
OUT ALREADY! I know how to open a zipper on the climb even if it is
pouring rain or snowing. That's why I buy my parkas in outdoor
clothing stores and not in bike shops. The other feature is that
when it's cold you need either a long sleeved synthetic material
undershirt (mountain climber style) or a mesh liner in the sleeves,
because touching the skin of a jacket is also a freezer.

Above all, make sure the parka has a hood that can be cinched down so
only your eyes and nose protrude. It was just such clothing that
helped Andy Hampsten win the Giro d'Italia on the Gavia pass. Mike
Neal pulled him off the bicycle at the summit and gave him a change of
dry clothes along with neoprene gloves and a hooded parka. Farther
down the hill he passed many riders standing there unable to
continue... no hands to operate the brakes. They were frozen.

I know what that is like from a descent off the Bonnet where I thought
I didn't need my gloves. Part way down I had a hard time stopping. I
could no longer feel where the brake levers were. Fortunately I had
gloves and double layer plastic newspaper bags that went up to my
armpits. Always take those along when going into the cold, "for just
in case."

Jobst Brandt

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

Quoted message said:

Lou Holtman said:

Yes. I saw once a television program where they measured the
difference in wind resistance between sloppy clothes en tight fit
clothes in a wind tunnel. I can't remembered the figures but I was
very surprised of the difference. Since then I make sure my cycling
clothes are tight fit. Even my winter clothes. No flapping clothes
for me anymore.

There is a much more important feature of fitting clothes for me
because the cold I run into is in the Alps in the summer (where it can
snow any day of the year!) If the jacket flaps it isn't warm because
there is a bucket brigade of oscillating air carrying the heat from
the body to the outdoors. You'll be surprised when descending in the
cold how much warmer it gets immediately, when you suppress the
flapping. This is a descending problem but...

I agree.

Quoted message said:

The stupid thing is bicycle clothing manufacturers don't know this and
keep selling flapable wind breakers with all sorts of vents. CUT IT
OUT ALREADY! I know how to open a zipper on the climb even if it is
pouring rain or snowing. That's why I buy my parkas in outdoor
clothing stores and not in bike shops. The other feature is that
when it's cold you need either a long sleeved synthetic material
undershirt (mountain climber style) or a mesh liner in the sleeves,
because touching the skin of a jacket is also a freezer.

Assos makes very good cycling clothes. Very expensive though. I have a Assos
winter jacket. Tight fit, warm and comfortable. Well worth the money.

Quoted message said:

Above all, make sure the parka has a hood that can be cinched down so
only your eyes and nose protrude. It was just such clothing that
helped Andy Hampsten win the Giro d'Italia on the Gavia pass. Mike
Neal pulled him off the bicycle at the summit and gave him a change of
dry clothes along with neoprene gloves and a hooded parka. Farther
down the hill he passed many riders standing there unable to
continue... no hands to operate the brakes. They were frozen.

Who won that stage and what was he wearing?

Quoted message said:

I know what that is like from a descent off the Bonnet where I thought
I didn't need my gloves. Part way down I had a hard time stopping. I
could no longer feel where the brake levers were. Fortunately I had
gloves and double layer plastic newspaper bags that went up to my
armpits. Always take those along when going into the cold, "for just
in case."

I never underestimate mountain wether (anymore). Learned it the hard way to.

Lou

Lou Holtman said:

Quoted message said:

Above all, make sure the parka has a hood that can be cinched down so
only your eyes and nose protrude. It was just such clothing that
helped Andy Hampsten win the Giro d'Italia on the Gavia pass. Mike
Neal pulled him off the bicycle at the summit and gave him a change of
dry clothes along with neoprene gloves and a hooded parka. Farther
down the hill he passed many riders standing there unable to
continue... no hands to operate the brakes. They were frozen.

Quoted message said:

Who won that stage and what was he wearing?

I only know what the pictures at Rifugio Bonetta on the summit show
for clothing. Brand names don't appear. You can get post cards with
pictures of it there.

Quoted message said:

Quoted message said:

I know what that is like from a descent off the Bonnett where I
thought I didn't need my gloves. Part way down I had a hard time
stopping. I could no longer feel where the brake levers were.
Fortunately I had gloves and double layer plastic newspaper bags
that went up to my armpits. Always take those along when going
into the cold, "for just in case."

Quoted message said:

I never underestimate mountain weather (anymore). Learned it the
hard way too.

A couple of years ago a friend with whom I was riding apparently
didn't believe me when I said it can snow any day of the year in the
Alps and brought a non-waterproof bicycle "wind breaker" without hood.
In Briancon with good sporting goods stores he bought a suitable parka
and I'm sure he'll not fail to take it along in the future.

Jobst Brandt

Quoted message said:

Quoted message said:

Quoted message said:

Fortunately I had gloves and double layer plastic newspaper bags
that went up to my armpits. Always take those along when going
into the cold, "for just in case."

Good tip, newspaper bags also work well over socks in case of rain. I
sometimes keep a large plastic trash bag to wear as a rain vest.

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

Quoted message said:

"(PeteCresswell)" <[email hidden]> wrote in message

Quoted message said:

Quoted message said:

Could the wind resistance of clothing really be a bigger factor
than
the diff
between fat and skinny tires?

Yes... easily.

Phil Holman said:

Air density. On cold days when more clothing is required, air density
is
increased so you get a double whammy. The ratio of air density at 30
deg
C and 0 deg C (constant pressure) is 303/273 = 1.11. If you coast at
30
mph in a toasty 30 degrees, this will reduce to 27 mph at a chilly 0
degrees. IMO this is a bigger factor than the additional clothes.

The speed difference will be proportional to the square root of the
density ratio... or in this case 1.11^.5 or 1.054. Floppy clothes
could
have a much larger effect. Also, the rolling resistance of tires
increases at low temperatures, which would probably make the
difference
between the tires more pronounced.

Yes you're right but actually drag is proportional to velocity squared
so 30^2 = v^2 *1.11
v = Sqrt (900/1.11) = 28.5 mph. For me, this is more significant than
the additional layers of clothing I wear ( I don't wear one inch thick
cycling tights).

Phil H

http://www.ihpva.org/Land/Whtlite.jpg

and track photos

i replaced a beat out of shape Conti TT on the front with a new pasela
tg aramid bead this morning and went at least 10 mph faster on the
morning commute.
always amazing what one person power cannot do.
the clothing excess may be comparable to pedals held horizontal v,
pedals held perpendicular to road surface when coasting on that long
grade

Quoted message said:

If the jacket flaps it isn't warm because
there is a bucket brigade of oscillating air carrying the heat from
the body to the outdoors. You'll be surprised when descending in the
cold how much warmer it gets immediately, when you suppress the
flapping. This is a descending problem but...

Quoted message said:

That's why I buy my parkas in outdoor
clothing stores and not in bike shops.

Quoted message said:

Above all, make sure the parka has a hood that can be cinched down so
only your eyes and nose protrude.

Any specific recommendations or photos?

--
Dave
dvt at psu dot edu