Advertise on Bikeforums.net



User Tag List

Results 1 to 9 of 9
  1. #1
    Dumb@s$ Jarhead mrt10x's Avatar
    Join Date
    Sep 2005
    Location
    Woodland Park CO
    My Bikes
    Calfee Dragon Fly Pro 1984 Pinarello Montello
    Posts
    1,111
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(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.

  2. #2
    Senior Member
    Join Date
    May 2005
    Location
    North Bend, WA
    My Bikes
    Cervelo Soloist / Cervelo P3
    Posts
    480
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(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.

  3. #3
    Senior Member jennings780's Avatar
    Join Date
    Apr 2005
    Location
    St. Louis, Missouri
    My Bikes
    '06 Cannondale CAAD8, '04 Cannondale Ironman 2000
    Posts
    422
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(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.

  4. #4
    Prefers Aluminum Sprocket Man's Avatar
    Join Date
    Feb 2005
    Location
    Honolulu
    My 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)
    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.

  5. #5
    TriBob
    Guest
    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.

  6. #6
    I get high on lactic acid ^*^BATMAN^*^'s Avatar
    Join Date
    May 2005
    Location
    Ontario, Canada
    My Bikes
    2003 Cervelo P3/2003 Trek 2000/2005 Norco EXC 2.0ht
    Posts
    725
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    ya....what they said.....dam people being on here more then me.....;p
    Road Bike- 2003 Trek 2000(out of service, rear triangle bent, looking for replacment)
    Triathlon/TT- 2003 Cervelo P3(also looking to upgrade to the P3C)
    MTB- 2006 Rocky Mountain Element Team
    Cats don't like riding on a bicycle......no matter how much duct tape you use.

  7. #7
    fixed road tri
    Join Date
    Nov 2004
    Location
    chitown
    My Bikes
    2004 guru trilte, 2003 jamis quest, 2004 specialized langster
    Posts
    153
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(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

  8. #8
    Dumb@s$ Jarhead mrt10x's Avatar
    Join Date
    Sep 2005
    Location
    Woodland Park CO
    My Bikes
    Calfee Dragon Fly Pro 1984 Pinarello Montello
    Posts
    1,111
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    guess I owe him a beer

  9. #9
    Race to train jrennie's Avatar
    Join Date
    May 2005
    Location
    suffering on the back
    Posts
    3,115
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I would much rather run into a headwind than ride into one.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •