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Sprint power

joeyhalloranjoeyhalloran Posts: 572
edited December 2010 in Amateur race
Hey guys, anyone got estimations on w/kg you might need over 5-30 seconds to be in with a chance of placing well in a 3/4 sprint? I know it depends a lot on other stuff like getting to the line as fresh as possible and positioning (and balls) but I just want a ball park figure.

Cheers
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  • i do not have a power meter and therefore have no clue whatsoever, but i imagine that is would be different every single race depending on the parcours, the nature of the race ie how aggressive it is, wind direction maybe?, who is racing would all make a difference to how many w/kg the winner produces just get out on your bike train and see hwat happens, there is now use someone saying you must be able to produce x amounts of watts for y amount on kg then you spending winter being able to produce that turning up and getting beaten in a sprint or failing that getting dropped before you even get to the sprint
  • Tom ButcherTom Butcher Posts: 7,137
    I wouldn't have thought w/kg was that useful - once you are up to speed your weight isn't a big factor in keeping it going - you want raw power and low drag - and of course all the other skill/experience stuff that makes a huge difference.

    it's a hard life if you don't weaken.
  • AnonymousAnonymous Posts: 79,692
    To be guaranteed of winning a Cat3/4 race, 30w/kg.
  • 30 w/kg seems pretty high to me :shock:

    I know that there are a lot of variables and me hitting a certain power/weight in sprint training means little, but I would just like to estimate how good my sprint is and if its something I need to work on. I was hoping for a range of values from people with PM that have placed in sprints and from that we can conclude a rough range for a "good 3/4 sprinter".
  • AnonymousAnonymous Posts: 79,692
    I just said if you wanted to be guaranteed of winning. The truth is anything will range from 10-20 w/kg over 5 seconds.
  • jibberjimjibberjim Posts: 2,810
    edited November 2010
    I was 4th in a 4th cat sprint at Hillingdon with a max watts of 800 (10 w/kg) for 5 seconds - I hit 1250 watts for 5 seconds in the middle of the race. Peak watts are irrelevant really everyone has enough - my 54kg wife was 6th in a 4th cat mens sprint in her first few races, her max 5seconds at the time wouldn't've been 750watts let alone anything more.

    It's all about position, and not being tired.
    Jibbering Sports Stuff: http://jibbering.com/sports/
  • and kicking at the right time, there is no use being able to bang out a powerful sprint if you go too late or too early, also i would say work on power and sprints as much as anything else, if you have a sprint good enough to win 3/4 cat races well then it probably won't be long until you are 2nd cat and then will need to be much stronger all round to make it to the finish contesting the win
  • PokerfacePokerface Posts: 8,640
    Yes - 10wkg or more is probably needed. The longer you can hold that, the better your chances.
  • batch78batch78 Posts: 1,320
    Cheers Nap, thats my winter training plan sorted, 2400watt sustained effort. :wink:
  • Tom ButcherTom Butcher Posts: 7,137
    Still not convinced w/kg is the most useful measure unless you are sprinting up a steep hill. Being lighter (half of that equation) is going to make some difference but on a flat sprint not much.

    it's a hard life if you don't weaken.
  • ProssPross Posts: 25,433
    If w/kg had any meaningful relevance then surely top climbers would also be top sprinters?
  • amaferangaamaferanga Posts: 6,789
    Pross wrote:
    If w/kg had any meaningful relevance then surely top climbers would also be top sprinters?

    W/kg over minutes (or hours even) is what matters for climbing.

    W/kg over seconds is what matters for sprinting.

    A climber may have an excellent 20 minute W/kg, but a very average 5 second or 30 second W/kg.

    So yes, W/kg is still meaningful.
    More problems but still living....
  • w/kg makes a large difference to acceleration, not top speed. So it does make up part of the sprinting equation.
  • PokerfacePokerface Posts: 8,640
    Plus - a lot of sprint finishes tend to be on slight uphill sections - to make it a little harder for the 'pure sprinter' types. I know I do really well on the pan flat sprints, but even a 1% gradient in the final sprint slows me down due to size.
  • P_TuckerP_Tucker Posts: 1,878
    I could do 1225w max last year, at 70kg and I don't think I finished outside the top 3 of any sprint I contested at 3rd cat level, flat or uphill. But I'm reasonably fit and have a vague idea of where to be and when, which as others have stated is much, much more important at this level. As a general rule, positioning will get you into the top 5 - your power will determine whether its first or fifith.
  • what power software are you using? Could you send me a file from a a race or two for me to look at the finish? What is required in the last 5 minutes-10seconds of a race to finish in the top 3?
  • P_TuckerP_Tucker Posts: 1,878
    Unfortunately not, I didn't use my PT in races last year. 1225w was produced in training; I doubt I got close to that in races.
  • ChiggyChiggy Posts: 261
    Cyclingpower.jpg

    Have a gander at this.
  • ChiggyChiggy Posts: 261
    what power software are you using? Could you send me a file from a a race or two for me to look at the finish? What is required in the last 5 minutes-10seconds of a race to finish in the top 3?

    You can calculate it from their Terminal Speed ( V max ) using 0.85 as the Cd.
  • P_TuckerP_Tucker Posts: 1,878
    Chiggy wrote:
    what power software are you using? Could you send me a file from a a race or two for me to look at the finish? What is required in the last 5 minutes-10seconds of a race to finish in the top 3?

    You can calculate it from their Terminal Speed ( V max ) using 0.85 as the Cd.

    Assuming that the finish was pan flat, no wind, no drafting etc?
  • P_Tucker wrote:
    Chiggy wrote:
    what power software are you using? Could you send me a file from a a race or two for me to look at the finish? What is required in the last 5 minutes-10seconds of a race to finish in the top 3?

    You can calculate it from their Terminal Speed ( V max ) using 0.85 as the Cd.

    Assuming that the finish was pan flat, no wind, no drafting etc?

    which is a logical basis for such a benchmark
  • P_TuckerP_Tucker Posts: 1,878
    P_Tucker wrote:
    Chiggy wrote:
    what power software are you using? Could you send me a file from a a race or two for me to look at the finish? What is required in the last 5 minutes-10seconds of a race to finish in the top 3?

    You can calculate it from their Terminal Speed ( V max ) using 0.85 as the Cd.

    Assuming that the finish was pan flat, no wind, no drafting etc?

    which is a logical basis for such a benchmark

    Except that bunch sprints don't take place in a laboratory, so trying to calculate power from terminal speed is utterly pointless.
  • As stated above - w/kg at the finish is pretty irrelevant. You want a good (4w/kg is nice) threshold so you are not hurting too much for the first hour and are in a good position towards the end, physically and psychologically, which you hold for the last 2-5 minutes.

    So there you are, final bend coming up, in that nose cone of the bunch (but not at the front). Hopefully you've done a few of the series by now so you may (should) know a bit about the relative strengths of those still around you. But best of all, you have been able to work out over the seasons what suits your physiology for the finish. Is it 5 seconds (when low accelerating mass could be useful?). Do you have a strong 20 seconds? Can you punch out a hurtful minute (when maybe you should go before the last bend?) You can only work this out through trial and error because on a turbo you will never get round to doing a threshold hour THEN do a critical 5s/10s/20s to see what might be your strong suit.

    Then factor in the course....

    Sod the power (though I use it) and see what you are good at by trying different tactics. Give it a couple of seasons before you truly know where your strengths and weaknesses are, unless you are phenomenally gifted and can do it all anyway. Then exploit and refine your self-knowledge into an invincible winning formula.
  • inseineinseine Posts: 5,772
    Thankfully lab measured power has got little to do with sprint performance at our level, though a good power to weight probably sees you in better shape at the end to contest the sprint.
  • P_Tucker wrote:
    P_Tucker wrote:
    Chiggy wrote:
    what power software are you using? Could you send me a file from a a race or two for me to look at the finish? What is required in the last 5 minutes-10seconds of a race to finish in the top 3?

    You can calculate it from their Terminal Speed ( V max ) using 0.85 as the Cd.

    Assuming that the finish was pan flat, no wind, no drafting etc?

    which is a logical basis for such a benchmark

    Except that bunch sprints don't take place in a laboratory, so trying to calculate power from terminal speed is utterly pointless.

    True, but at least its a theoretical benchmark.
  • It's a theorhetical benchmark and is a useful training target.

    I found out that in the 3rd cat races where I podium'd I have usually had to punch out 700+W for the last 30 secs. So I train at 700W reps.
  • I watched someone do a series of peak watt bike tests with a small break in-between each and it quite constantly went down by around 100watts from an initially massive result to something average. It goes to show how easy it is to ruin yourself before the end of a race. Having said that I paid no attention to it and still continue to ride myself into the ground for no reason while racing or generally riding, although as training it must be doing something because after finishing the London triathlon I jumped on a watt bike next to the finish line and peaked at 1656.

    Train harder and ride better is the only answer
  • Lion-OLion-O Posts: 48
    as someone said before go for broke in races. if you blow up you blow up just dont do it again the next week. why worry abouts watts etc its not the stronger rider that will win a race its the canniest! tatics can easliy sort a race out. Drop the sprinter before the finish over the hill and its yours!
  • It's a theorhetical benchmark and is a useful training target.

    I found out that in the 3rd cat races where I podium'd I have usually had to punch out 700+W for the last 30 secs. So I train at 700W reps.

    and you weigh what, 98kg or so? ;-)
  • P_TuckerP_Tucker Posts: 1,878
    P_Tucker wrote:
    P_Tucker wrote:
    Chiggy wrote:
    what power software are you using? Could you send me a file from a a race or two for me to look at the finish? What is required in the last 5 minutes-10seconds of a race to finish in the top 3?

    You can calculate it from their Terminal Speed ( V max ) using 0.85 as the Cd.

    Assuming that the finish was pan flat, no wind, no drafting etc?

    which is a logical basis for such a benchmark

    Except that bunch sprints don't take place in a laboratory, so trying to calculate power from terminal speed is utterly pointless.

    True, but at least its a theoretical benchmark.

    So, you calculate a figure with a margin of error of at best 25%. How does that help, exactly?
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