What's the function of lead out?

Discussion in 'Road Cycling' started by sogood, Aug 29, 2007.

  1. sogood

    sogood New Member

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    I read that lead outs allows the rider behind to attain a higher top speed during their final sprint. What's the mechanism of it? Does it mean that without a lead out, one can't attain the same top speed?
     
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  2. JAPANic

    JAPANic New Member

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    A few things I can think of...
    1)
    If the lead out rider is going at full speed and is strong it will be hard for other teams to over take him. His ace sitting behind him can relax and watch for counter attacks.

    2)
    If there is a crash the riders at the front are safe.

    3)
    You can go much faster by sprinting away from behind somebody than trying to pull away in front of somebody. More than 20% more energy efficiency to come from behind than to lead.
     
  3. sogood

    sogood New Member

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    Thanks. This is part that I am interested in.

    I can understand how over a fixed distance, a lead out can save the protected rider energy until a sprint is necessary. But if it was a standing start without a distance factor ie. Same rider behind a lead out and one where he/she sprints alone, would a lead out permit the protected rider to achieve a higher top speed?
     
  4. JAPANic

    JAPANic New Member

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    Yes. (assuming the guy being protected is as fast as or close to as fast as his lead out. If you don't have the legs nothing much is going to help you....but coming into the slip stream you get a kind of sling shot effect....

    http://en.wikipedia.org/wiki/Slipstream
     
  5. sogood

    sogood New Member

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    Yes, I understand the slip stream effect.

    But for a given power of the protected rider and the air resistance once exposed from the slipstream, I am curious why the protected rider can achieve a higher speed (assuming the lead out rider is not as strong). Hence your point on that sling shot effect is interesting. How does that work coming out of a slipstream?
     
  6. JAPANic

    JAPANic New Member

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    The accelerating 2nd rider will have momentum greater than the lead out who is fighting against air resistance and having less momentum as a result.

    The 2nd rider will then have to deal with the air resistance himslef and this will eventually slow him down as well but his initial momentum is going to be greater and therefore will feel like a sling shot.

    Lead out has to face full air pressure and resistance.
    The follower has less air pressure and resistance and can increase his momentum as a result.

    All about momentum after you lose the air pressure benefits...

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

    (I'm no physicist BTW and this is my own opinion).
     
  7. tafi

    tafi Member

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    It really is all about aerodynamics. The rider following the leadout man can drop back about a length and then accelerate whilst still in the slipstream. By the time the sprinter starts to come around the leadout man, he is already travelling a few kph faster (and is also fresher for the "kick"). Once the sprinter comes past the leadout (who is pretty shagged by now) he still has to contend with air resistance but is now putting out maximum power and has the advantage of a higher starting speed.

    It isn't quite correct to talk of momentum because that varies with different riders.

    Also note that the maximum speed is attained at the most important time, as the sprinter is coming around the rider in front, because it helps him get a gap in front of the rest. If he gets a gap then the rest of the pack can't benefit from his slipstream.

    Of course there is also the advantage of having a teammate who can sit up and get in everyone else's way.
     
  8. sogood

    sogood New Member

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    I also had some issues with that explanation on the basis of momentum. The ability to reach a higher speed prior to leaving the slipstream created by the lead out rider makes physical sense.
     
  9. pistole

    pistole New Member

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    - its also to raise the pace at the head of the pack to such a level that no one can get the jump on the one's being led-out.

    - eg , the front of the peloton is being pulled at , say, 60kmh ... nothing much is going to be getting away from it anytime soon.

    .
     
  10. youhaditcoming

    youhaditcoming New Member

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    Hi.. i think that's the main reason of a leadout really. Only winning matters, be it at 40 kph or 60 kph.
     
  11. JAPANic

    JAPANic New Member

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    4) advertising... the team at the front gets the best TV commercial.
     
  12. carpediemracing

    carpediemracing New Member

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    beating a dead horse perhaps but I haven't been here since forever.

    A leadout is a tactical weapon used to try and stack the deck in favor of the sprinter being led out.

    Typically the top sprinters in a field are approximately equal in speed etc. (and sometimes your team may have a slightly weaker sprinter so you need to give him a boost). If everyone sprints for the line (watch the finish of Worlds where Boonen wins), it's chaotic and extremely unpredictable.

    A team which is willing to sacrifice themselves can work the odds in their favor. It avoids (sort of) the unpredictable finishes and keeps the number of contenders down. This is because good leadout will string out the field in single file - forcing anyone who wants to move up to go into the wind (or, if they have supportive teammates, use up their leadout men just to get into position). Sometimes you'll see parallel leadouts as teams vie for control of road space before a critical turn.

    Properly done, a leadout will reduce the pool of potential winners from, say, 10 or 15 or 20 racers to about 3 or 4.

    I wrote a bit on this:
    http://sprinterdellacasa.blogspot.com/2007/07/tactics-leadouts.html

    cdr
     
  13. Eden

    Eden New Member

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    I don't know if anyone brought this up yet - I don't know about you all, but I don't think I can reach my top speed completely on my own if only because if I try to ramp up to it, I tire out before I get going as fast as I've ever been with a lead out. I personally have a pretty short sprint, so having someone there to take the brunt of the work before I have to go full out myself is great.
     
  14. youhaditcoming

    youhaditcoming New Member

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    It's funny how 4 or more guys sacrifice themselves for 1 guy... No question it is absolutely necessary, the team will also share the winner's $ price, but ...is it truly a team sport ?? Only the winner appears on the Newspaper the next day, only the winner steps on the podium and above all only him will see his name on the record books later on in life...
     
  15. Frigo's Luggage

    Frigo's Luggage New Member

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    For christ's sake, please stop blogging and start uploading more You Tube videos. I am jonesing for some racing and your stuff is the closest I can get to the real thing.
     
  16. carpediemracing

    carpediemracing New Member

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    heh thanks and sorry. I've been sick, moved, got married, and went on a honeymoon in the last couple months. This meant I essentially stopped riding and haven't done a race in forever. I'll try and change that for next year.

    However, I've discovered I uploaded non-optimized versions of my helmet cam tapes to youtube so am in the process of uploading improved clips - should be much clearer, text better, action more visible.

    Also, I'll try and get a couple old clips, previously unposted, up there. Not as exciting as some of the others but still interesting.

    On the team sport bit - it depends on what you consider a team sport. Even in many team sports, there's the "star" - basketball, baseball, football (all have "most valuable player" awards). There's a lot of equity put into an effort by both the leadout racer/s and the sprinter. I count my various leadout men (in Cat 3s, nothing more serious than that) over the last 20+ years as some of my best friends in the world - and virtually all of them were at my wedding just recently.

    cdr
    sprinterdellacasa.blogspot.com (look for helmet cam label for the clips, look for sprinting for leadout and related stuff).
     
  17. youhaditcoming

    youhaditcoming New Member

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    Well... a decade ago i was so very proud of helping our team leader, until i recently bumped into him and he tells me; ...you are confusing me with somebody else (which ended our "conversation") I insist that you can name any team which won the NBA any year... but can you tell who were Sean Kelly or Freddy Maertens or Abdoujaparov leadout guys ?? Even If you do... their names are certainly not on cycling history books.

    Congratulations on your wedding !
     
  18. Crankyfeet

    Crankyfeet New Member

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    Well everything has been covered but wanting to throw in another analogy, having a leadout is like going downhill before you pull out your sprint. You've got about 200-250m maximum that you can mash it in a sprint before your legs seize up from lactic acid. The faster you can go before you start this effort, the faster you'll be going at max speed after 200m.

    The points about the lead out train stringing out the field are also a big positive as well.
     
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