Power Data Estimates for the climbing stages

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May 18, 2009
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Taxus4a said:
:D:D

When we could meet for riding? :p
Don't make up.....I went and got some popcorn hoping you and poopoo were gonna have a flame war with your whack english. That would have been hilarious.
 
CycloAndy said:
First 'clean' winner of Hautacam in years :rolleyes:
If Contador & Froome were here they would have ridden much faster and Nibali would have kept up as well. But boy did they ride slow today. It was like a Sunday group ride with the Dad's.

Because there's no accelerations, Nibs basically time trialled up the climb. There was zero tactics involved. His time is representative of that fact.
 
I was going on this:

At the speeds typically attained during time trials on a velodrome, decreased aerodynamic drag provides a more substantial benefit. In theory, this more than compensates for the reduction in V. O2max up to approximately 3200 to 3500m, which is the optimal altitude for 2 to 40km time trials,[14] allowing times 4 to 4.5% faster than at sea level.
But there is also this:

Med Sci Sports Exerc. 1999 Nov;31(11):1665-76.
Comparing cycling world hour records, 1967-1996: modeling with empirical data.
Bassett DR Jr1, Kyle CR, Passfield L, Broker JP, Burke ER.


Abstract
PURPOSE:
The world hour record in cycling has increased dramatically in recent years. The present study was designed to compare the performances of former/current record holders, after adjusting for differences in aerodynamic equipment and altitude. Additionally, we sought to determine the ideal elevation for future hour record attempts.
METHODS:
The first step was constructing a mathematical model to predict power requirements of track cycling. The model was based on empirical data from wind-tunnel tests, the relationship of body size to frontal surface area, and field power measurements using a crank dynamometer (SRM). The model agreed reasonably well with actual measurements of power output on elite cyclists. Subsequently, the effects of altitude on maximal aerobic power were estimated from published research studies of elite athletes. This information was combined with the power requirement equation to predict what each cyclist's power output would have been at sea level. This allowed us to estimate the distance that each rider could have covered using state-of-the-art equipment at sea level. According to these calculations, when racing under equivalent conditions, Rominger would be first, Boardman second, Merckx third, and Indurain fourth. In addition, about 60% of the increase in hour record distances since Bracke's record (1967) have come from advances in technology and 40% from physiological improvements.
RESULTS AND CONCLUSIONS:
To break the current world hour record, field measurements and the model indicate that a cyclist would have to deliver over 440 W for 1 h at sea level, or correspondingly less at altitude. The optimal elevation for future hour record attempts is predicted to be about 2500 m for acclimatized riders and 2000 m for unacclimatized riders.
But both studies are a little old.
 
Merckx index said:
This is a very interesting talk by David Epstein, author of The Sports Gene, a book which I have discussed here before. He points out that Eddy Merckx’s hour record was extended only 10 m by Boardman, when he was restricted to a similar bike. Sosenka later added about 250 m to that, but he also tested positive several years before and after that record. Merckx did set his record at over 2000 meters altitude, which would provide a significant aerodynamic advantage, though some of that would be lost because of the reduced oxygen levels. I think the most favorable estimates are that he might have gained 2-3% in speed, though most subsequent attempts have been at sea level, by choice of the riders.
The Mexico City track was at 2300m

49.43km/h requires 105-110W less power than it would at sea level.

Power reduction due to lower partial pressure of O2 say 12%.

So accounting for that, Merckx equivalent sea level performance would be ~47.4 km/h. That's a 4% drop in speed.

On the other side, Merckx didn't pace it very well.


The reason most hour record attempts and records have been done/set at sea level is mostly logistical, and a function of where suitable track surfaces have been located.

Very few quality tracks have been available at significant altitude in convenient locations.
 
A few comments in this item about rider's power over last few stages, including Roger's Stage 16 win:

http://home.trainingpeaks.com/blog/article/2014-tour-de-france-week-3-power-analysis?feed=70c86158-aad7-4b07-8cc3-7c383b9bd61b&utm_source=feedburner&utm_medium=email&utm_campaign=Feed:+trainingpeaks/XAlX+(TrainingPeaks+Blog)

Rogers' peak 20 minute power came during the climb up the Porte de Balés where he held 441 watts, 6.09w/kg. During the entire climb Rogers held 428 watts, 5.91w/kg. for 35:16
 
Aug 13, 2009
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Some like to say that Nibali is winning now that the race is slower (Less doping) that he has always been at this level......He was 4 minutes slower in 2008.

Valverde talked about a headwind today, likely true in the 2nd 1/2 of the climb
 
Race Radio said:
Some like to say that Nibali is winning now that the race is slower (Less doping) that he has always been at this level......He was 4 minutes slower in 2008.

Valverde talked about a headwind today, likely true in the 2nd 1/2 of the climb
He was 23 years old and had just done the Giro (where he got 11th while being a dom), so that's a really stupid remark. You don't measure one's prior level by picking a bad performance, instead you should measure his better/best early performances and compare those with his currently better/best performances.

I expected as much from Benotti, but I honestly thought you wouldn't post such garbage.

Here's a different data point for you: in 2007 he rode faster up Zonc (where drafting doesn't mean all that much) than everyone else did in 2010 and 2011 except Basso and Anton. That means he was faster than Evans, Scarponi, Contador and himself. He was 22 years old and it was his first GT.
 
hrotha said:
Was it a bad performance, though? He was 9th (12th if you include the CERA guys).
13th on the day (though hardly matters).

And given the field that wasn't a great performance imo. I certainly think he'd be faster if he hadn't done the Giro. Ofc I think the biggest factor is of anti-doping.
 
Aug 13, 2009
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Netserk said:
He was 23 years old and had just done the Giro (where he got 11th while being a dom), so that's a really stupid remark. You don't measure one's prior level by picking a bad performance, instead you should measure his better/best early performances and compare those with his currently better/best performances.

I expected as much from Benotti, but I honestly thought you wouldn't post such garbage.

Here's a different data point for you: in 2007 he rode faster up Zonc (where drafting doesn't mean all that much) than everyone else did in 2010 and 2011 except Basso and Anton. That means he was faster than Evans, Scarponi, Contador and himself. He was 22 years old and it was his first GT.
Oh brother :rolleyes:

Given your habit for cherry picking and obfuscation your outrage over comparing the same rider on the same climb is comical.
 
Race Radio said:
Oh brother :rolleyes:

Given your habit for cherry picking and obfuscation your outrage over comparing the same rider on the same climb is comical.
23 year old does his 2nd and 3rd GT back-to-back and isn't great in the 3rd. Then you use a single performance from that 3rd GT to show he has had a massive improvement (compared to his perhaps single best climbing performance ever), despite the fact that he had performed much better before that.

Great counter that you can give me a set of rolleyes and an ad hominem.
 
Mar 18, 2009
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thrawn said:
That's right. The Earth is flat.
I don't believe that there was ever any scientific evidence that the Earth was flat. Even if there was, however, it didn't expire simply due to old age - science just doesn't work that way.
 
acoggan said:
I don't believe that there was ever any scientific evidence that the Earth was flat. Even if there was, however, it didn't expire simply due to old age - science just doesn't work that way.
Belief in a flat earth is a myth. But there were very compelling scientific arguments for geocentrism back in the day, which made perfect sense with the data they had at the time.

Same could apply to old, especially pioneering studies on this field. Science marches on.

Not sure what you're arguing to be honest.
 
If we are going to do cherry picking from performances from the early days between GT contenders today, nobody would be safe (except Quintana). Not even Contador would make the cut with that 2005 Tour de France performance. You can always make the argument of:

- The other contenders were doped to the gills while my idol was not or
- My idol was always doped from the early days (Andy or Quintana) or
- My idol was always doped, but now most riders have tamed down a lot so his natural talent will finally show better.

These are arguments that will be always hard to prove. The only think hard data to proof doping that we have are the power numbers, blood profiles and positive results.

And nowadays power numbers don't proof much if riders always keep it at limit amounts. Even for a guy that always did around 5.5 Watts/Kg and today is doing the 6 watts/kg will not be proof enough.

To me in order to make a better conclusion is to group all the variables to investigate a cheat. All the criteria available. Not just one but all. And then jump to conclusions. But performances alone are just not enough. Ex. I cannot single out Froome just on performances alone because they are within natural ability. I have to combine that with his early performances of his life. I also have to combine that with the team association and doctors association, etc, etc.
 
Aug 13, 2009
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Netserk said:
23 year old does his 2nd and 3rd GT back-to-back and isn't great in the 3rd.
The correct response would have been this as it would add context to the discussion......instead you made it personal, tossing out insults like "Stupid" and "Garbage".
 
Race Radio said:
The correct response would have been this as it would add context to the discussion......instead you made it personal, tossing out insults like "Stupid" and "Garbage".
I called your post stupid, not you. Truth is that your post was stupid and it was garbage, as I said something I expected from Benotti, not you, as I actually don't think you're stupid. Great thing you showed how it was done, instead of (as the only one) responding with an ad hominem. I see that in your two responses so far, you haven't addressed the content of my posts.
 
Mar 18, 2009
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hrotha said:
Belief in a flat earth is a myth. But there were very compelling scientific arguments for geocentrism back in the day, which made perfect sense with the data they had at the time.

Same could apply to old, especially pioneering studies on this field. Science marches on.

Not sure what you're arguing to be honest.
That science marches on, or not, but doesn't just die of old age.
 
acoggan said:
That science marches on, or not, but doesn't just die of old age.
Yes, but, huh, no one argued it did. "That study is old so take it with a grain of salt"="As more data has been looked at since it was published, its findings may not be valid anymore or may need to be qualified".
 
Mar 13, 2009
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