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Mom
7th September 2009, 19:59
Wind chill is something we hear about, sometimes we even read about it. For a few of us we have experienced it. Dangerous stuff!

I see the weather that tells me the temperature is 6 degrees/feels like 2 degrees warnings. I have experienced the chill that goes beyond a shiver. The slow quiver, that dulls your ability to think clearly, and makes you unable to string a decent sentence together is no fun, and quite deadly if not corrected.

So what is wind chill exactly? Obviously travelling at speed creates a wind chill factor.

How do you work it out? Just because you are baking (read sweating) in the sun wearing thermals and all the lined gear does not prevent you from freezing and then some riding home after the sun has set.

What is wind chill?

How dangerous is it?

AllanB
7th September 2009, 20:05
It's bad stuff alright.

And riding faster to get home quicker :whistle: only makes it worse........

The old newspaper stuffed down your chest can starve it off a bit.

Mom
7th September 2009, 20:11
It's bad stuff alright.

And riding faster to get home quicker :whistle: only makes it worse........

The old newspaper stuffed down your chest can starve it off a bit.

Yeah, I know, I am not above becoming a rustling lump of warmish newspaper if I have to, but how does it work? How do you work it out?

I have ridden in cold before, you dress for it, your finger tips freeze (yes, yes heated grips, I hear you loud and clear) your toes are so numb, you have to kick them against the kurb to return blood flow kind of cold.

Wind chill, how big a difference does it make to the actual temp? A big one obviously.

psycho22
7th September 2009, 20:16
If in doubt look at wikipedia

http://en.wikipedia.org/wiki/Wind_chill

Mom
7th September 2009, 20:19
Thanks for that, I wonder why I did not think of it myself really :doh:

psycho22
7th September 2009, 20:22
Well I was kinda wondering why you didn't think of that or at least google but i didn't want to be a smart arse....That and I couldn't remember the exact definition

Katman
7th September 2009, 20:26
Is riding at 100kph into no wind the same as standing still in a 100kph wind?

Mom
7th September 2009, 20:28
Well I was kinda wondering why you didn't think of that or at least google but i didn't want to be a smart arse....That and I couldn't remember the exact definition

Oh, well there goes that attempt to get others thinking about wind chill and how it might affect them I guess. They should know to simply wiki it.

Perhaps you could actually explain for those that dont bother to follow the link how it actually works?

Edbear
7th September 2009, 20:31
Thanks for that, I wonder why I did not think of it myself really :doh:

Dasokay, we understand. :hug:











Bein' both female and blonde... :whistle:

psycho22
7th September 2009, 20:32
Can't be farked really so I will just copy and paste for those to lazy to click a button.

Wind chill is the apparent temperature felt on exposed skin due to wind. The degree of this phenomenon depends on both air temperature and wind speed. The wind chill temperature (often popularly called the wind chill factor) is always lower than the air temperature for values where the wind chill formula is valid. In cases where the apparent temperature is higher than the air temperature, the heat index is used instead.

Explanation

The human body loses heat largely by evaporative cooling and convection[1][2]. The rate of heat loss by a surface depends on the wind speed above that surface: the faster the wind speed, the more readily the surface cools. For inanimate objects, the effect of wind chill is to reduce any warmer objects to the ambient temperature more quickly. For most biological organisms, the physiological response is to maintain surface temperature in an acceptable range so as to avoid adverse effects. Thus, the attempt to maintain a given surface temperature in an environment of faster heat loss results in both the perception of lower temperatures and an actual greater heat loss increasing the risk to adverse effects such as frostbite and death.


As to Katmans question I would hazard a guess as to yes it would be roughly the same

Mom
7th September 2009, 20:34
Can't be farked really so I will just copy and paste for those to lazy to click a button.

Wind chill is the apparent temperature felt on exposed skin due to wind. The degree of this phenomenon depends on both air temperature and wind speed. The wind chill temperature (often popularly called the wind chill factor) is always lower than the air temperature for values where the wind chill formula is valid. In cases where the apparent temperature is higher than the air temperature, the heat index is used instead.

Explanation

The human body loses heat largely by evaporative cooling and convection[1][2]. The rate of heat loss by a surface depends on the wind speed above that surface: the faster the wind speed, the more readily the surface cools. For inanimate objects, the effect of wind chill is to reduce any warmer objects to the ambient temperature more quickly. For most biological organisms, the physiological response is to maintain surface temperature in an acceptable range so as to avoid adverse effects. Thus, the attempt to maintain a given surface temperature in an environment of faster heat loss results in both the perception of lower temperatures and an actual greater heat loss increasing the risk to adverse effects such as frostbite and death.


As to Katmans question I would hazard a guess as to yes it would be roughly the same

Thanks for that, as clear as mud really. So if I am travelling at 100 kph and the air temp is 10 degrees celcius, what is the wind chill factor?

psycho22
7th September 2009, 20:35
This might help

Katman
7th September 2009, 20:37
As to Katmans question I would hazard a guess as to yes it would be roughly the same

So imagine riding at 80mph for 2 hours in a 4 degree celsius temperature. (4 degC = 40 degF)

http://www.springfrog.com/weather/wind-chill.htm

http://www.onlineconversion.com/temperature.htm

I don't have to imagine.

Mom
7th September 2009, 20:40
This might help

I am not wearing my glasses, it looks like a little purple graph thing really.

psycho22
7th September 2009, 20:41
You would be in serious need of some heat after that.

Get heated grips.:woohoo:

And maybe a heated jacket.

psycho22
7th September 2009, 20:44
I am not wearing my glasses, it looks like a little purple graph thing really.

Wind chill at 100kph would be roughly 4 degrees so that means the air hitting your face feels like it is 4 degrees

psycho22
7th September 2009, 20:46
That doesn't sound quite right but according to the calculator Steve put up it is.

And that wouldn't factor in wind that might or might not be present at the time.

Katman
7th September 2009, 20:48
That doesn't sound quite right but according to the calculator Steve put up it is.

And that wouldn't factor in wind that might or might not be present at the time.

It depends on the ambient temperature.

Mom
7th September 2009, 20:49
Wind chill at 100kph would be roughly 4 degrees so that means the air hitting your face feels like it is 4 degrees

So, on a hot summers day, travelling at 100 kph the wind on my face would feel like 4 degrees? That does not seem right?

Or are you saying 100 kph lowers the air temp by 4 degrees, so that the actual air temp is lowered by 4 degrees at 100kph? Is that constant?

psycho22
7th September 2009, 20:51
And probably many other things so all you can have is a rough indication.

That or buy a guage if you really want to know exactly.

johan
7th September 2009, 20:51
If you have a glass of water outside, ambient temperature +2 degrees C, the wind is 20 knots.

That's some serious wind chill.

Will the water freeze?

Katman
7th September 2009, 20:52
So, on a hot summers day, travelling at 100 kph the wind on my face would feel like 4 degrees? That does not seem right?

Or are you saying 100 kph lowers the air temp by 4 degrees, so that the actual air temp is lowered by 4 degrees at 100kph? Is that constant?

As I said, it depends on the ambient temperature.

Over a certain temperature the wind actually incurs a heat factor.

Edbear
7th September 2009, 20:54
As I said, it depends on the ambient temperature.

Over a certain temperature the wind actually incurs a heat factor.

Bit like KB then, blowing hot and cold... ;)

Mom
7th September 2009, 20:54
Will some one do me the honour of actually explaining this to me. I dont want to read wiki till my brain bleeds attempting to understand it. In simple terms what is it, how does it work (apart from making you freeze faster, I took that as read already) and how do you calculate it?

psycho22
7th September 2009, 20:55
So, on a hot summers day, travelling at 100 kph the wind on my face would feel like 4 degrees? That does not seem right?

Or are you saying 100 kph lowers the air temp by 4 degrees, so that the actual air temp is lowered by 4 degrees at 100kph? Is that constant?

That was calculated at 10 degrees so if by a hot day you mean say 20 degrees, the air that is hitting you feels like it is roughly 8 degrees. Basically you would feel like your are in a room with the room temperature at 8 degrees. No it isn't constant as wind gusts or lulls would change it as would varying speed.

Mom
7th September 2009, 20:56
As I said, it depends on the ambient temperature.

Over a certain temperature the wind actually incurs a heat factor.

How does ambient temperature affect it? You mean on a really stinking hot summers day you can actually feel hotter? I know that one. So how doe s this work?

psycho22
7th September 2009, 20:56
Sorry im not very good at explaining things

Mom
7th September 2009, 21:00
That was calculated at 10 degrees so if by a hot day you mean say 20 degrees, the air that is hitting you feels like it is roughly 8 degrees. Basically you would feel like your are in a room with the room temperature at 8 degrees. No it isn't constant as wind gusts or lulls would change it as would varying speed.

So at 20 degrees air temp, I am feeling 8 degrees of air temp through my partially unzipped jacket while travelling at 100 kph? How the hell do I not freeze (figuratively of course)? 8 degrees is cold, I have never felt cold in the summer time. I love the "wind chill" then.

johan
7th September 2009, 21:00
I used to ride to school in -15 degrees and snow on my two stroke.

The only thing that kept you warm was wind proof clothing and many layers.

But us kids never thought twice about it, it was mostly fun sliding around the snow dodging traffic.

Katman
7th September 2009, 21:01
How does ambient temperature affect it?

Well it's one of the two factors involved in calculating it for a start.

:whistle:

Mom
7th September 2009, 21:03
Well this has been informative. I learned heaps :D Hopefully others did too :yes:

Katman
7th September 2009, 21:06
So at 20 degrees air temp, I am feeling 8 degrees of air temp through my partially unzipped jacket while travelling at 100 kph? How the hell do I not freeze (figuratively of course)? 8 degrees is cold, I have never felt cold in the summer time. I love the "wind chill" then.

At 20 degC travelling at 100kph it would feel like 18.3 degC.

(As long as there was no tail or head wind to factor in).

Whereas at 35 degC it would feel like 40 degC.

marty
7th September 2009, 21:10
Wind chill at 100kph would be roughly 4 degrees so that means the air hitting your face feels like it is 4 degrees

i don't understand your reasoning.

the graph is in degrees F and only goes to +40 F,- which is only +4 C. Shows that at 100km/h, in +4 C, the wind chill experienced on exposed skin takes 15 F off the actual temp, taking the 'feels like' temp down to +25 F, or -3 C.

and yes - 100km/h on your bike is the same as standing in a 100km/h wind.

wind chill is a major factor in skydiving in the winter - it can be -20C out the door, at 120mph, minus wind chill factor, the temp feels like -40/-50 C and colder. Can be difficult to feel for the droge chute ball if your hands are frozen

oldrider
7th September 2009, 21:21
When you eventually come down to a Brass Monkey and strike a "really cold one" you will probably feel it (wind chill) to the full!

It's probably about as bad as it (wind chill) gets for motorcycling in New Zealand too!

Leaving the warmer areas at minus 10 to 12 degrees Celsius and then getting into the "cold spots", say in the Lindis Pass for instance, can really test your mettle.

If there is hoar frost lurking about, temperatures really plummet as you negotiate the slippery icy bits of the road.

You can't stop because you would become a hazard or target for other road users to hit. (the bastards will hit you too, if you are not careful)

Of course the more you move and the faster you go the colder it gets! :cold:

It is the wind chill that makes the difference, I have seen many a grown man in tears from the cold!

I feel sorry for the Northern riders, because they are not acclimatised for the lower temperatures on the way down, it just gets colder and colder and colder! :eek5:

Must feel good heading home though. :sweatdrop

Ophir (near the Brass site) is supposed to be the coldest "official" recorded temp in NZ, that was 3 July 1995 minus 21.6 Celsius.

As you can see from the date, close to or on Queens birthday week end and the Brass Monkey rally!

That would be as good as it gets for wind chill experience for any motorcyclist in New Zealand!

Come on down an enjoy the experience, you might be lucky and get a cold one! :whistle:

Katman
7th September 2009, 21:24
Come on down an enjoy the experience, you might be lucky and get a cold one! :whistle:

You're not a very good salesman.

:crazy:

psycho22
7th September 2009, 21:28
i don't understand your reasoning.

the graph is in degrees F and only goes to +40 F,- which is only +4 C. Shows that at 100km/h, in +4 C, the wind chill experienced on exposed skin takes 15 F off the actual temp, taking the 'feels like' temp down to +25 F, or -3 C.

and yes - 100km/h on your bike is the same as standing in a 100km/h wind.

wind chill is a major factor in skydiving in the winter - it can be -20C out the door, at 120mph, minus wind chill factor, the temp feels like -40/-50 C and colder. Can be difficult to feel for the droge chute ball if your hands are frozen

I know I used an online calculator for that one ( Not Steves one ) and it didn't sound right. You don't know what you can trust online. My apologies.

Use Steves one at least it's accurate

10bikekid
7th September 2009, 22:02
Don't know how accurate this is but we always say that the wind chill in the winter is about -10 deg at 100kph eg 14 deg at 100kph = 4 deg , you got to remember that with all your gear and helmet on you usually cook when you stop if the temps over 17 deg so its probably not far wrong

I rode from Whangamata to Auckland on Sat at o let say 12 deg and even with liners in my gloves most of my fingers went white

marty
7th September 2009, 22:21
as a guide, that would be pretty accurate. the colder the ambient though, the greater the split

10bikekid
7th September 2009, 22:25
this was the best chart I could find

Temperature
(°C)
Wind Speed in Kilometres per Hour (kph)
0 10 20 30 40 50 60 70 80

20 19 16 15 14 13 13 13 13
15 13 10 8 7 6 5 5 5
10 8 4 1 -1 -2 -2 -3 -3
5 2 -3 -6 -8 -9 -10 -11 -11
0 -3 -9 -13 -15 -17 -18 -18 -19

-5 -8 -15 -20 -22 -24 -25 -26 -27
-10 -14 -22 -27 -30 -32 -33 -34 -34
-15 -19 -28 -34 -37 -39 -41 -42 -42
-20 -25 -35 -40 -44 -47 -48 -49 -50
-25 -30 -41 -47 -51 -54 -56 -57 -58

-30 -36 -47 -54 -59 -62 -64 -65 -66
-35 -41 -54 -61 -66 -69 -71 -73 -73
-40 -47 -60 -68 -73 -77 -79 -81 -81
-45 -52 -66 -75 -81 -84 -87 -88 -89
-50 -58 -73 -82 -88 -92 -94 -96 -97

:crazy: that didn't come out so well did it but it looks like once your speed gets over 60 kph the change isn't great so in brief where looking at say a 10 deg reduction at 15 deg ambient, 19deg reduction at 0 and a 7deg reduction at 20

Mom
8th September 2009, 08:30
Come on down an enjoy the experience, you might be lucky and get a cold one! :whistle:

Brrrrrrrr. You can keep that. I am a hot house flower me, anything short of tropical temps and I am freezing.

We dont wear enough clothing up here, we dont really need to, so it is easy to get caught out with the cold. A few weekends ago I went to visit a friend about an hour north of here. It was a beautiful sunny day, I was in a t-shirt at home. I considred putting my thermals on to ride up there, but did not bother, short ride, lovely day and all that. My jacket has a quilted thermal liner in it so I should be ok? Boy did I regret it half an hour into the trip. Anyplace the sun was not, was bloody cold.

I dont get cold on my bike generally, I resemble a pass the parcel package when I am all geared up, layer upon layer of yummy warmth :D

Goblin
8th September 2009, 08:57
I feel sorry for the Northern riders, because they are not acclimatised for the lower temperatures on the way down, it just gets colder and colder and colder! :eek5:Awww go on with ya! There's at least 2 of us who are hard enuff. We get to acclimatise through Reporoa/Broadlands fog.:cold:

MSTRS
8th September 2009, 09:16
If you have a glass of water outside, ambient temperature +2 degrees C, the wind is 20 knots.

That's some serious wind chill.

Will the water freeze?

Nope. It can't get colder than the ambient temperature.
Wind chill is the perceived temp for a living being.

oldrider
8th September 2009, 09:41
Awww go on with ya! There's at least 2 of us who are hard enuff. We get to acclimatise through Reporoa/Broadlands fog.:cold:

Hey, don't break the myth, I want to think I feel warmer as I go further North! :sweatdrop :ride: :sunny:

oldrider
8th September 2009, 09:46
Brrrrrrrr. You can keep that. I am a hot house flower me, anything short of tropical temps and I am freezing.

I dont get cold on my bike generally, I resemble a pass the parcel package when I am all geared up, layer upon layer of yummy warmth :D

HHhhmmmm, I guess Maha was left holding the "pass parcel package" when the music stopped then! :lol:

davebullet
8th September 2009, 11:40
As I said, it depends on the ambient temperature.

Over a certain temperature the wind actually incurs a heat factor.

The concorde would lengthen by upto 30cm at supersonic speeds due friction induced heat due to the windspeed. Even though it is bloody cold up there.

Could be handy to lengthen things down here as well with a bit of friction... but sadly... I cannot rub fast enough.

MSTRS
8th September 2009, 11:45
The concorde would lengthen by upto 30cm at supersonic speeds due friction induced heat due to the windspeed. Even though it is bloody cold up there.

Could be handy to lengthen things down here as well with a bit of friction... but sadly... I cannot rub fast enough.

Friction is about resistance, not the speed. I suggest you work on your grip.

LBD
8th September 2009, 14:10
Then there is the contribution moisture makes....if you are damp and riding in the dry, the moisture evaporates off creating an even greater cooling affect...

Windchill? Working at 4500m, at night with a minus 40c ambient and 40 gusting to 60 knot wind inside a open steel shell repairing a genset before the antifreeze freezes and splits the engine block....F&*%#* that was a cold night....

yungatart
8th September 2009, 16:20
You know me Mom...can't cope with the cold at all...basically I give up riding in winter, as I just can't get enough layers on (even with a root...)
My brain ceases to function and my extremeties won't work!
As fpor a good explanation of wind chill, James Duece can explain it so even a numbskull like me can understand it. Give him a PM...

boman
8th September 2009, 16:43
Don't know how accurate this is but we always say that the wind chill in the winter is about -10 deg at 100kph eg 14 deg at 100kph = 4 deg , you got to remember that with all your gear and helmet on you usually cook when you stop if the temps over 17 deg so its probably not far wrong

I rode from Whangamata to Auckland on Sat at o let say 12 deg and even with liners in my gloves most of my fingers went white

About -10 degrees at 100kph is what I have been told and tend to work on. Eg ride to work air temp 1 - 2 deg, with wind chill about -8 deg. Don't know if this is correct, but have been really cold on a 10min ride to work on a frosty morning.

PrincessBandit
8th September 2009, 18:50
The concorde would lengthen by upto 30cm at supersonic speeds due friction induced heat due to the windspeed. Even though it is bloody cold up there.

Could be handy to lengthen things down here as well with a bit of friction... but sadly... I cannot rub fast enough.

So rubbing and friction don't lengthen things at all for you? You poor thing! :laugh:


Oh, it was more length you were after then?

The ride we did on the weekend was in glorious sunny weather, but even with my hot grips on my fingers were still white when I got off the bike in Ngatea. Haha, they were toasty underneath and chilly over the top. That's the Hauraki Plains/Waikato for you though. **runs and hides** :dodge:

sinned
8th September 2009, 20:23
You know me Mom...can't cope with the cold at all...basically I give up riding in winter, as I just can't get enough layers on (even with a root...)
My brain ceases to function and my extremeties won't work!
As fpor a good explanation of wind chill, James Duece can explain it so even a numbskull like me can understand it. Give him a PM...
Now we have been informed about wind chill. What to do about it? Lots of layers are not necessarily effective.
I wear Icebreaker bodyfit 260 with an Oxford chillout on top. Next is the Revit Cordora jacket with liner. That works for me in 0 degree temps. The Oxford chillout is very effective and the zipped high neck keeps all wind out. Heated grips warm the blood flowing back up the arms.

Mom
8th September 2009, 20:31
Now we have been informed about wind chill. What to do about it? Lots of layers are not necessarily effective.
I wear Icebreaker bodyfit 260 with an Oxford chillout on top. Next is the Revit Cordora jacket with liner. That works for me in 0 degree temps. The Oxford chillout is very effective and the zipped high neck keeps all wind out. Heated grips warm the blood flowing back up the arms.

Zero degrees is no protection, in fact you are probably better off setting out at zero all rugged up and warm the effect of wind chill is less the colder you get??????

Someone??????

Squid
8th September 2009, 21:05
Zero degrees is no protection, in fact you are probably better off setting out at zero all rugged up and warm the effect of wind chill is less the colder you get??????

Someone??????

I guess the effect would be less but by that time you'd woudnt care any more which is always a bad sign.

Why do you want to calculate what the wind chill factor anyways? You could always get a $15 thermometer yoo-hoo glued to the front of your bike in the airflow and measure the temp... :crazy:

10bikekid
8th September 2009, 21:25
this was the best chart I could find

Temperature
(°C)
Wind Speed in Kilometres per Hour (kph)
0 10 20 30 40 50 60 70 80

20 19 16 15 14 13 13 13 13
15 13 10 8 7 6 5 5 5
10 8 4 1 -1 -2 -2 -3 -3
5 2 -3 -6 -8 -9 -10 -11 -11
0 -3 -9 -13 -15 -17 -18 -18 -19

-5 -8 -15 -20 -22 -24 -25 -26 -27
-10 -14 -22 -27 -30 -32 -33 -34 -34
-15 -19 -28 -34 -37 -39 -41 -42 -42
-20 -25 -35 -40 -44 -47 -48 -49 -50
-25 -30 -41 -47 -51 -54 -56 -57 -58

-30 -36 -47 -54 -59 -62 -64 -65 -66
-35 -41 -54 -61 -66 -69 -71 -73 -73
-40 -47 -60 -68 -73 -77 -79 -81 -81
-45 -52 -66 -75 -81 -84 -87 -88 -89
-50 -58 -73 -82 -88 -92 -94 -96 -97

:crazy: that didn't come out so well did it but it looks like once your speed gets over 60 kph the change isn't great so in brief where looking at say a 10 deg reduction at 15 deg ambient, 19deg reduction at 0 and a 7deg reduction at 20


About -10 degrees at 100kph is what I have been told and tend to work on. Eg ride to work air temp 1 - 2 deg, with wind chill about -8 deg. Don't know if this is correct, but have been really cold on a 10min ride to work on a frosty morning.


Yep and theres the chart to prove it ,
In Europe there is a bike camp held at a place that is -10 deg or lower on the way there they are riding with wind chill of - 35 :crazy:I'm afraid not that keen as I wont Ride at under 12 deg :oi-grr:

BMWST?
8th September 2009, 21:45
Is riding at 100kph into no wind the same as standing still in a 100kph wind?

yes 10 char

Grahameeboy
8th September 2009, 21:49
Oh, well there goes that attempt to get others thinking about wind chill and how it might affect them I guess. They should know to simply wiki it.

Perhaps you could actually explain for those that dont bother to follow the link how it actually works?

You can get burnt from wind chill..happened to me a lot

bogan
8th September 2009, 23:28
Why do you want to calculate what the wind chill factor anyways? You could always get a $15 thermometer yoo-hoo glued to the front of your bike in the airflow and measure the temp... :crazy:

Thats not how wind-chill works! The air temp is the same no matter how fast you go (well for this application anyway). Wind chill affects people because people are hotter than the air, and the faster you go the more air passes and cools you down to that temp, like a blood filled radiator pretty much. The wind chill factor is the how cold the wind makes it feel, and has to be calculated as it cannot be directly measured.

10bikekid
9th September 2009, 06:29
Just out of interest acording to one of the charts I read , at 35 deg the wind chill is + 5 deg, eg 40 deg and at 30 its close to 0 , eg temp stays he same, no wonder its so hot on our bikes on those days :devil2:

Mom
9th September 2009, 06:50
Why do you want to calculate what the wind chill factor anyways? You could always get a $15 thermometer yoo-hoo glued to the front of your bike in the airflow and measure the temp... :crazy:

I dont want to know how cold it is, I wan to know how cold it is going to feel, so I can dress appropriately. Apart from that I am a curious kinda gal, I am interested in finding out how wind chill works.

Owl
9th September 2009, 07:23
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NordieBoy
9th September 2009, 09:22
Why do you want to calculate what the wind chill factor anyways? You could always get a $15 thermometer yoo-hoo glued to the front of your bike in the airflow and measure the temp... :crazy:

I used an indoor/outdoor thermometer and put the outdoor bit on the fork leg in the airflow.

Was amazing to see the difference sometimes.