How can Cavendish go so much faster?

donrhummy
donrhummy Posts: 2,329
edited July 2010 in Pro race
Aerodynamics. While it looks on TV like he's got to be putting out 25% more watts than everyone else, that's not the case.

A BIG part of how he goes so fast is that he gets MUCH more aero/lower than any other sprinter. Watch him and he looks almost like he's descending while sprinting, he's so low on the bike. At those speeds, that's a HUGE difference.

Using Kreuzotter's algorithms, consider the following two scenarios:

(Both on flat ground, 2mph headwind, 15 lb bike, 160 lb rider, 70 inches tall, 1200 watts)

Hands on bar tops yields a speed of 34.5 mph.
Hands on the drops yields a speed of 39.8 mph.

Going that fast, aerodymanics makes a bigger difference than putting out more watts. Just moving your hands to the drops gives a 15.3% improvement. So if Thor, Petacchi and Cavendish all put out the SAME watts (and assuming the same weight, etc), Cavendish will go faster.

And here's the amazing thing, if he instead was as "un-aero" as the other riders but instead put out 15.3% more watts (1383.6 watts in this example), he'd only go 36.7 mph!! (Only a 6.3% gain) That's right, watts have a diminishing return against the wind.

Comments

  • donrhummy
    donrhummy Posts: 2,329
    Yes, but I backed it up with evidence. :lol: :P

    I do remember reading an article in ProCycling where they talked about how they'd worked all year on him being able to put out his best watts while in that aero position.
  • gethmetal
    gethmetal Posts: 208
    Makes sense to me. Is not the biggest impediment to us as cyclists air resistance?
    75% is a number that sticks in my mind, but I'm sure forum folk will correct me soon enough.

    What Mark appears to have (to me) is an impressive combination of a high power output which is compressed into a fairly small and stocky frame.

    Hi-PO and small frontal area, if you will. In the best ratio that human beings can currently muster.

    I'm not a fan, but his performance is beyond question. Good work.
  • rjh299
    rjh299 Posts: 721
    Drugs...









    Joke, he's a hero!
  • msw
    msw Posts: 313
    I remember L'Equipe ran a piece during last year's Tour where they asked a number of ex-pros and coaches the same question, and they agreed about the aerodynamics. One said that his greater track experience gave him the nerve to put his head right down without looking where he's going, which a road sprinter would instinctively find difficult, helping him get a bit lower. Certainly if you look at Julian Dean in the head-on shot of this year's Paris finish he's nearly as low as Cav but looking ahead throughout.

    Of course it's also easier to do that when there's nobody in front of you...
    "We're not holding up traffic. We are traffic."
  • giant_man
    giant_man Posts: 6,878
    No really ....... drugs
  • bearfraser
    bearfraser Posts: 435
    bigger motor on his bike!!!!!!!!!!!!