Does Colder Weather = Slower Biking, and if so, why?

Colorado Bicycler said:

It seems to me that when I bike at about 40F or colder on my mtn bike
with 1.75 slicks, everything slows way down, including me!

So, is it psychological, physical, the tires, the lubricant, SAD, or am
I just imagining things.

1. Denser air

2. You have to heat all the air you breathe to body temperature.
The harder you work, the more air you have to heat as you breathe more.
So you reach a calorie limit that's self-reenforcing pretty fast.

--
Ron Hardin
[email hidden]

On the internet, nobody knows you're a jerk.

Ron Hardin said:

Colorado Bicycler said:

It seems to me that when I bike at about 40F or colder on my mtn bike
with 1.75 slicks, everything slows way down, including me!

So, is it psychological, physical, the tires, the lubricant, SAD, or am
I just imagining things.

1. Denser air

How much denser is it at 40 degrees vs 70 degrees?
And how much would such a change slow a rider down?

Quoted message said:

2. You have to heat all the air you breathe to body temperature.
The harder you work, the more air you have to heat as you breathe more.
So you reach a calorie limit that's self-reenforcing pretty fast.

So your saying that it would be even tougher to ride at 20 degrees vs 40
because your body has to heat the air even more?

Ken
--
On the internet, nobody knows you're a jerk - unless you act like a jerk
on the internet too. - Quote modified by Ken M.

http://www.xenodochy.org/ex/abstract/mileage.html

This website estimates a 6% drop in car mileage from a 30 degreeF drop
in temperature.

Anyone else have some figures relating air density to temperature
change, and its effect on bicycling?

Colorado Bicycler said:

http://www.xenodochy.org/ex/abstract/mileage.html

This website estimates a 6% drop in car mileage from a 30 degreeF drop
in temperature.

Anyone else have some figures relating air density to temperature
change, and its effect on bicycling?

I was curious about this and did a bit of surfing and found
this:http://www.icebike.org/Articles/SlowerWinter.htm

Some interesting theories.

Ken
--
On the internet, nobody knows you're a jerk - unless you act like a jerk
on the internet too. - Quote modified by Ken M.

Thanks for the input.

But, even going down familiar hills, where I am not pedaling, the whole
thing goes slower! I know this because I keep pretty good track of my
coasting downhill speeds.

Ken, thanks for the icebiker site. I should have gone to this right
away.

Somewhere, a similar post has gotten lost, so this post may end up
being a repeat!

Thanks - I should have known to look at the icebike site first, as I
often refer others to that site. Appreciate greatly your web search.

I know, I worked really hard today!

Colorado Bicycler said:

So, is it psychological, physical, the tires, the lubricant, SAD, or am
I just imagining things.

Dunno about you, but I slowed WAY down this morning when I realized how
much black ice there was out there.

Bill

--------------------------------------------------------------
| They that can give up essential liberty to obtain a little |
| temporary safety deserve neither liberty nor safety. |
| --Benjamin Franklin |
--------------------------------------------------------------

No ice (white or black) today!

IMHO, it is all the clothes you have to layer up in. Be that as it may I do
notice a slow down the colder it gets. Well the extra clothes and the wind
driven chill factor.

Jim

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

Quoted message said:

It seems to me that when I bike at about 40F or colder on my mtn bike
with 1.75 slicks, everything slows way down, including me!

So, is it psychological, physical, the tires, the lubricant, SAD, or am
I just imagining things.

Colorado Bicycler said:

http://www.xenodochy.org/ex/abstract/mileage.html

This website estimates a 6% drop in car mileage from a 30 degreeF drop
in temperature.

I don't think they factored in the volumetric efficiency the engine
gains from ingesting cooler air, but that's probably for the better in
terms of comparison to bicycles!

Quoted message said:

Anyone else have some figures relating air density to temperature
change, and its effect on bicycling?

The biggest effect is that the bicycles remain hanging in the garage
on cold days. Sigh...

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

Mark Hickey said:

The biggest effect is that the bicycles remain hanging in the garage
on cold days. Sigh...

Mine is languishing in the basement. So at least it's
warm.

Scott

Ron Hardin said:

Colorado Bicycler said:

It seems to me that when I bike at about 40F or colder on my mtn bike
with 1.75 slicks, everything slows way down, including me!

So, is it psychological, physical, the tires, the lubricant, SAD, or am
I just imagining things.

1. Denser air

2. You have to heat all the air you breathe to body temperature.
The harder you work, the more air you have to heat as you breathe more.
So you reach a calorie limit that's self-reenforcing pretty fast.

Air has a pretty low specific heat, i.e., it's
not too hard to warm it up, so I rather doubt
#2 has much of an effect.

A bigger effect probably occurs because the
colder air is dryer, leading to faster
dehydration through exhalation (and mucus
production 🙂 ), so you have to carry more
water at a pound per pint.

Scott

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

Quoted message said:

Colorado Bicycler said:

http://www.xenodochy.org/ex/abstract/mileage.html

This website estimates a 6% drop in car mileage from a 30 degreeF drop
in temperature.

I don't think they factored in the volumetric efficiency the engine
gains from ingesting cooler air, but that's probably for the better in
terms of comparison to bicycles!

Quoted message said:

Anyone else have some figures relating air density to temperature
change, and its effect on bicycling?

The biggest effect is that the bicycles remain hanging in the garage
on cold days. Sigh...

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

There's no doubt that colder weather reduces speed, big time. I average
about 15 mph in warm weather, maybe 12 in slightly subfreezing temps and
barely 10 in very cold weather, say below 10 F. I wonder what factors are
involved and speculate about the following:

1. Air density
2. Bulky clothing
3. Less efficiency in the bearings
4. Inability to breathe hard for long
5. Breathing stale air when I have a mask on
6. General sluggishness
7. Greater percentage of riding in dark conditions

OTOH, I have a very good long term record of avoiding flat tires in the
winter (knock on wood) Why would that be?

Ron Wallenfang said:

There's no doubt that colder weather reduces speed, big time. I average
about 15 mph in warm weather, maybe 12 in slightly subfreezing temps and
barely 10 in very cold weather, say below 10 F. I wonder what factors are
involved and speculate about the following:

1. Air density
2. Bulky clothing
3. Less efficiency in the bearings
4. Inability to breathe hard for long
5. Breathing stale air when I have a mask on
6. General sluggishness
7. Greater percentage of riding in dark conditions

I think most of the above are pretty valid - if you're wearing a mask,
you're certainly recycling some C02, and if it's dark it's reasonable
for the human brain to slow down a bit to try to protect itself. I am
less motivated in the winter just because I've decided that's my
"off-season" (even if the weather is actually pretty good - you can't
ride hammer and tongs all year round).

Quoted message said:

OTOH, I have a very good long term record of avoiding flat tires in the
winter (knock on wood) Why would that be?

It's just too cold to change a flat? ;-)

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

"Colorado Bicycler" <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Thanks for the input.

But, even going down familiar hills, where I am not pedaling, the whole
thing goes slower! I know this because I keep pretty good track of my
coasting downhill speeds.

I've got a 4% grade hill on one end of my circuit and a lower 3% on the
other, and I've noted a general decrease in top speed going down the taller
hill where the effects of air resistance would be most pronounced. About
29mph where 32mph was normal, in a repeatable manner. That's about 10%.

That's in ~40 degree vs ~80 degree temperatures, pedalling all the way,
with intermediate points showing about the same for both temperatures
(i.e., I pass the 10mph, 21mph points about the same place regardless of
temperature). I go over a 1.44 mile circuit for multiple laps, but even
then the differences seem to be beyond normal variability. When the
temperatures drop I rarely get over 30mph by the bottom, while 32mph is
routine. It's a 30mph zone so I don't feel too bad being +/- 10% of the
limit, and that's why I notice the speed.

I'd also submit that the effect of slight breezes are more pronounced.