Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Triathlon Swim / Bike / Run your thing? Drop in our new triathlon forum for the latest in training & gear. From beginner to expert, and sprint to ironman.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 09-20-05, 02:38 PM   #1
mrt10x
Dumb@s$ Jarhead
Thread Starter
 
mrt10x's Avatar
 
Join Date: Sep 2005
Location: Woodland Park CO
Bikes: Calfee Dragon Fly Pro 1984 Pinarello Montello
Posts: 1,110
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Headwind Bike vs Run

I have an ongoing argument with a co-worker. We are both active milatary and primarily runners, but have both taken up road biking recently as a change. He insists that it is harder to ride into a 15 mph headwind than it is to run into it. I think he is just a better runner than rider and therefore it "feels" harder. I think that aero and mechanical advantage a bike offers has to make riding into a 15 mph wind easier than running into it. You Tri guys seem like the perfect bunch to answer the question...of course it could just be an individual thing I guess.
mrt10x is offline   Reply With Quote
Old 09-20-05, 04:13 PM   #2
chrisesposito
Senior Member
 
Join Date: May 2005
Location: North Bend, WA
Bikes: Cervelo Soloist / Cervelo P3
Posts: 480
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by mrt10x
I have an ongoing argument with a co-worker. We are both active milatary and primarily runners, but have both taken up road biking recently as a change. He insists that it is harder to ride into a 15 mph headwind than it is to run into it. I think he is just a better runner than rider and therefore it "feels" harder. I think that aero and mechanical advantage a bike offers has to make riding into a 15 mph wind easier than running into it. You Tri guys seem like the perfect bunch to answer the question...of course it could just be an individual thing I guess.
I think that the frontal area of a rider down on the aerobars is less than the frontal area of a runner going at the same speed, and so the drag would probably be less. Not having convenient access to a wind tunnel, I have no data for this, though.
chrisesposito is offline   Reply With Quote
Old 09-20-05, 04:27 PM   #3
jennings780
Senior Member
 
jennings780's Avatar
 
Join Date: Apr 2005
Location: St. Louis, Missouri
Bikes: '06 Cannondale CAAD8, '04 Cannondale Ironman 2000
Posts: 422
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
How do you define harder?
I know that on a pretty flat road with little or no wind I can ride at about 22mph for a pretty long time. On the same flat road I can run at about 7 1/2mph for a pretty long time also.

Now lets assume there is a 10mph headwind. How much do you think performance will drop off? I would think that on the bike I would drop to about 15 - 16mph (approx. based on experience). I would also guess that my running speed may drop to 6 1/2mph. These are just loose guesses - but approximately based on experience.

If this were the case the drop in speed on the bike would be over 1/3rd while the drop on the run would be about 1/8th.

I think that when biking at 18 or 20 or 22mph wind is so much of what you are fighting against that adding a headwind will slow you down a lot. I think that running 6 - 8mph the main thing you are fighting is gravity and friction. Adding a headwind will make a difference but not as much as on the bike.
jennings780 is offline   Reply With Quote
Old 09-20-05, 04:55 PM   #4
Sprocket Man
Prefers Aluminum
 
Sprocket Man's Avatar
 
Join Date: Feb 2005
Location: Honolulu
Bikes: Wife: Trek 5200, C'dale Rush Feminine, Vitus 979 Me: Felt S25, Cervelo Soloist, C'dale Killer V500, Miyata Pro (fixie)
Posts: 2,671
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by jennings780
I think that when biking at 18 or 20 or 22mph wind is so much of what you are fighting against that adding a headwind will slow you down a lot. I think that running 6 - 8mph the main thing you are fighting is gravity and friction. Adding a headwind will make a difference but not as much as on the bike.
I concur with jennings.
Sprocket Man is offline   Reply With Quote
Old 09-21-05, 06:08 AM   #5
TriBob
Guest
 
Bikes:
Posts: n/a
Mentioned: Post(s)
Tagged: Thread(s)
Quoted: Post(s)
Quote:
Originally Posted by Sprocket Man
I concur with jennings.
1

Add your speed to the speed of the wind. You can see you are fighting higher total wind speed. Even in the aero position it is hard work.
  Reply With Quote
Old 09-21-05, 09:07 AM   #6
^*^BATMAN^*^
I get high on lactic acid
 
^*^BATMAN^*^'s Avatar
 
Join Date: May 2005
Location: Ontario, Canada
Bikes: 2003 Cervelo P3/2003 Trek 2000/2005 Norco EXC 2.0ht
Posts: 725
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
ya....what they said.....dam people being on here more then me.....;p
^*^BATMAN^*^ is offline   Reply With Quote
Old 09-21-05, 05:25 PM   #7
lilscotboy
fixed road tri
 
Join Date: Nov 2004
Location: chitown
Bikes: 2004 guru trilte, 2003 jamis quest, 2004 specialized langster
Posts: 153
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
thinking back to the days when i studied aerodynamics at college

the resistance you feel due to the air is proportionate to the speed you are travelling at squared.

therefore riding at higher speeds you will be expending much more energy (more drag from the wind in proportion to your rolling resistance) than running at lower speeds (proportionately more rolling resistance or friction with the ground).

so basically

what jennings said
lilscotboy is offline   Reply With Quote
Old 09-22-05, 03:36 PM   #8
mrt10x
Dumb@s$ Jarhead
Thread Starter
 
mrt10x's Avatar
 
Join Date: Sep 2005
Location: Woodland Park CO
Bikes: Calfee Dragon Fly Pro 1984 Pinarello Montello
Posts: 1,110
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
guess I owe him a beer
mrt10x is offline   Reply With Quote
Old 09-23-05, 01:30 PM   #9
jrennie
Race to train
 
jrennie's Avatar
 
Join Date: May 2005
Location: suffering on the back
Bikes:
Posts: 3,115
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I would much rather run into a headwind than ride into one.
jrennie is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 02:32 AM.