Power Data Estimates for the climbing stages

[Fearless Greg Lemond]

Good evening all - my first post in this thread, just to share a scientific article which I think might be of interest to you:

"Accuracy of Indirect Estimation of Power Output From Uphill Performance in Cycling" by Grégoire P. Millet of the Université de Lausanne.

http://www.researchgate.net/publica...wer_Output_From_Uphill_Performance_in_Cycling

Sorry if re-post! If new, let me know what you think!

Co - written by Grappe? Will be a hit here, grazie mille.

 

[gooner]

If you can get your hands on this month's ProCycling magazine, Daniel Friebe has an excellent article on this topic and the differing interpretations of it. Pinotti, Grappe, Julien Pinot, Weber, Ross Tucker, JV and Kerrison contribute to it.

Vetoo gets s few mentions. He asked Pinotti for his data from the Giro a few years back for some research and Pinotti said Vetoo was no more than 5 watts out in his calculations from it. He said he was extremely accurate in his work.

Vayer doesn't come out with a lot of credibility on this.

 

[thehog]

If you can get your hands on this month's ProCycling magazine, Daniel Friebe has an excellent article on this topic and the differing interpretations of it. Pinotti, Grappe, Julien Pinot, Weber, JV and Kerrison contribute to it.

Vetoo gets s few mentions. He asked Pinotti for his data from the Giro a few years back for some research and Pinotti said Vetoo was no more than 5 watts out in his calculations from it. He said he was extremely accurate in his work.

Vayer doesn't come out with a lot of credibility on this.

You mean all the pseudo-scientists who think Dawg is normal are good and Vayer lacks credibility because he calls out Froome.

Your ability to show impartiality is second to none Gooner

btw We're have you been for the last 3 weeks whilst Sky have been combusting from the inside?

 

[poupou]

If you can get your hands on this month's ProCycling magazine, Daniel Friebe has an excellent article on this topic and the differing interpretations of it. Pinotti, Grappe, Julien Pinot, Weber, Ross Tucker, JV and Kerrison contribute to it.

Vetoo gets s few mentions. He asked Pinotti for his data from the Giro a few years back for some research and Pinotti said Vetoo was no more than 5 watts out in his calculations from it. He said he was extremely accurate in his work.

Vayer doesn't come out with a lot of credibility on this.

Until now we have scientists cautious with their words and guys like Vayer, calling a cat a cat while being like a bull in a chinese shop.
Who has been wrong? What is the score?

 

[FoxxyBrown1111]

So why are riders today so much faster than those of the past? There may be some technological improvements, but I believe we discussed on another thread these, and came to the conclusion that bike weights, e.g., could not account for the difference.

Distance of stages and distance in general. Even if dismissed by some as irrelevant, I go with one who shall know:
Fignon. In his book he said in his time the best riders won b/c attrition played a major role. Today riders can hide in slipstream all day long and still win mountain stages.
In his days such lucky events didn´t take place.
It´s a difference if you ride 4.500 km with 1 or zero rest days and 250 k mountain stages, or 3.300 km with two rest days where your mountain stages go 150 k.
With all this I don´t mean I think today is dope-free (it wasn´t back then either), I just say the times of this TdF are not as absurd as they are made by some here...

BTW, read somewhere that Peraud was 5.8 W/kg at Hautacam. "Vayers book says": believable. Just a mention.

 

[red_flanders]

Distance of stages and distance in general. Even if dismissed by some as irrelevant, I go with one who shall know:
Fignon. In his book he said in his time the best riders won b/c attrition played a major role. Today riders can hide in slipstream all day long and still win mountain stages.
In his days such lucky events didn´t take place.
It´s a difference if you ride 4.500 km with 1 or zero rest days and 250 k mountain stages, or 3.300 km with two rest days where your mountain stages go 150 k.
With all this I don´t mean I think today is dope-free (it wasn´t back then either), I just say the times of this TdF are not as absurd as they are made by some here...

BTW, read somewhere that Peraud was 5.8 W/kg at Hautacam. "Vayers book says": believable. Just a mention.

Riders couldn't hide in slipstreams in the Fignon era?

What? Attrition doesn't play a role? No, not if everyone's on blood boosters. You should probably be aware that Fignon specifically stated that doping in cycling was revolutionized by EPO. He refused to take it and retired when he realised that he couldn't keep up with the pack fodder anymore. States it outright in his bio.

 

[Dear Wiggo]

Advancements in slipstreams and drafting. Makes sense.

 

[FoxxyBrown1111]

Advancements in slipstreams and drafting. Makes sense.

LOL. You really got it, didn´t you?
It´s a difference if 5 riders arrive at the last climb more or less together, or a group of 20 with their doms... Got it now? Got it? Really? ... Ahhh
If you wanna joke around with me, better come up with arguments. If Afrank wasn´t here ... ok, leave it that.

 

[FoxxyBrown1111]

Riders couldn't hide in slipstreams in the Fignon era?

What? Attrition doesn't play a role? No, not if everyone's on blood boosters. You should probably be aware that Fignon specifically stated that doping in cycling was revolutionized by EPO. He refused to take it and retired when he realised that he couldn't keep up with the pack fodder anymore. States it outright in his bio.

They could OFC. For the first four of five climbs or so. You remember the solo rides of the early 80s. There wasn´t big groups surviving at the end. It was basically man against man at max... Time gaps were tremendous in MTFs. You all know that.

What Fignon meant was b/c of the long tough stages and amazing total kilometers, there was survival of the fittest in its truest sense...

 

[red_flanders]

They could OFC. For the first four of five climbs or so. You remember the solo rides of the early 80s. There wasn´t big groups surviving at the end. It was basically man against man at max... Time gaps were tremendous in MTFs. You all know that.

What Fignon meant was b/c of the long tough stages and amazing total kilometers, there was survival of the fittest in its truest sense...

What he meant was that the level of the champions was much higher than the bottle-carriers, and attrition would weed out the chumps.

Not so much after EPO.

 

[FoxxyBrown1111]

What he meant was that the level of the champions was much higher than the bottle-carriers, and attrition would weed out the chumps.

Not so much after EPO.

I didn´t say the opposite. My post was meant to answer why 70s/80s times of 33 mins downed to 30 1/2 mins in the 2014-TdF very much make sense if we account for length in total and per stage, and further that there wasn´t big groups arriving at the final climb where you can hide inside and save energy....

Lemond today repeated what I read some years ago. Slipstream saves up to 30% of energy. I guess he meant in flat parts. The affect still is there if going uphill at 20+ km/h, even though not that stark...

 

[hrotha]

There were usually a couple of ultra-long stages and more stages over 200 km in the 80s, but by and large the distances weren't that different, I think. According to Wikipedia (yeah yeah), the 1984 Tour de France Fignon won had 5 mountain stages:
St 11 - Pau - Guzet-Neige (227 km)
St 17 - Grenoble - Alpe d'Huez (151 km)
St 18 - Le Bourg-d'Oisans - La Plagne (185 km)
St 19 - La Plagne - Morzine (186 km)
St 20 - Morzine - Crans-Montana (141 km)

That seems to be the norm throughout the 80s, with 1989 having particularly short mountain stages (91, 125, 136, 147, 165 and 175 km).

 

[FoxxyBrown1111]

While 1987 was crazy OTOH. In general mountain stages got shorter and shorter as total distance did, while rest days expanded, and stages were cut down (from 24/23 (?) to 21 now)...
Anyway, still my post was meant to explain that 33 mins 35-40 years ago to 30.5 minutes now are plausible...

 

[sittingbison]

the difference being that there is no discernible improvement prior to EPO:
1974 33:20 18.72 km/h (Raymond Poulidor)
1978 33:29 18.64 km/h (Mariano Martinez)
1981 33:40 18.53 km/h (Lucien Van Impe)
1982 33:13 18.79 km/h (Beat Breu)

then EPO is introduced and this :
1993 29:35 20.89 km/h (Jaskula-Rominger) -RECORD


And Lance with his competitive juices flowing:
2001 29:48 20.74 km/h (Lance Armstrong)
2005 30:34 20.22 km/h (Basso-Armstrong)

So where does this performance fit? In the new cleans era of cycling?
2014 30:32 20.24 km/h (Nibali-Peraud)

What about the differences in bike weight and perhaps more importantly rotating wheel weight? Certainly a difference there...

The bikes including 1993 record were all of a much ness around 9kg

Ever since they have been 6.8kg (rumoured less in 2001) so Nibs was at the same bike weight as Lance.

 

[thehog]

Advancements in slipstreams and drafting. Makes sense.

The winds are very different now. Thinner air due to global warming.

 

[SeriousSam]

When the precision of power estimates (or even power meter measures, which are essentially estimates with smaller confidence intervals) is quoted, they're usually giving a percentage. x watt +-1% for instance.

Why is that? Why is there greater uncertainty for larger values?

 

[Roude Leiw]

You mean all the pseudo-scientists who think Dawg is normal are good and Vayer lacks credibility because he calls out Froome.

Your ability to show impartiality is second to none Gooner

You should read the article, but gooner summarized it accurately. The flying finn gets top marks though. Calling out or not is not the point, but accuracy in the methodology compared to actual numbers, then publish the results. Based on this, call out whoever you wish to call out.

The real solution would be the UCI collecting the data from the power meters and analyzing it, putting people on the bench when it stinks, but that won't happen. The rest is guesswork, even though inspired one which i like a lot reading.

 

[FoxxyBrown1111]

The winds are very different now. Thinner air due to global warming.

You can do better Hog...

 

[thehog]

You can do better Hog...

I can do much better, I agree.

http://www.scientificamerican.com/article/global-warming-more-baseball-home-runs/

I'm sure Walsh will quote this around Vuelta time

"It has not been proven, but I think ultimately it will be proven that the air is thinner now, there have been climactic changes over the last 50 years in the world, and I think that's one of the reasons balls are carrying much better now than I remember."

 

[el_angliru]

When the precision of power estimates (or even power meter measures, which are essentially estimates with smaller confidence intervals) is quoted, they're usually giving a percentage. x watt +-1% for instance.

Why is that? Why is there greater uncertainty for larger values?

It's difficult to explain in a totally foreign language but it's probably because some forces (or parts of the equations) are squared, which means a change of one unit (for instance) gives an even bigger change when units are higher.

 

[Ferminal]

It's only greater uncertainty in nominal terms if the error is expressed as a proportion...

 

[karlboss]

I was having a look at veloclinic's post tour washup and I'm convinced he has his numbers wrong for stage 14. It doesn't fit the curve developed by the other climbs this Tour, which would indicate either his numbers are wrong or everyone rode really fast that. Further more Ten Dam's power numbers are consistently (by a similar margin each time)low next to the estimations, but on that stage they are wayyy low. Leading me to believe there was an extremely helpful wind, or a data point is out ie length or height of the climb.
The other option is that the leaders decided as a group to only ride to their best on that stage and on the same day Ten Dam re calibrated his power meter.
Most riders even have a relatively stable curve taking stage 14 out, except Nibali which is to be expected as he was actually riding within himself on some stages.

 

[zigmeister]

You should read the article, but gooner summarized it accurately. The flying finn gets top marks though. Calling out or not is not the point, but accuracy in the methodology compared to actual numbers, then publish the results. Based on this, call out whoever you wish to call out.

The real solution would be the UCI collecting the data from the power meters and analyzing it, putting people on the bench when it stinks, but that won't happen. The rest is guesswork, even though inspired one which i like a lot reading.

Just substitute power meter files with biopassport.

 

[Escarabajo]

Ferrari's opinion:

http://www.53x12.com/do/show?page=indepth.view&id=148

Nibali 6.3 Watts/Kg in Hautacam.

 

[Escarabajo]

Ferrari's opinion:

http://www.53x12.com/do/show?page=indepth.view&id=148

Nibali 6.3 Watts/Kg in Hautacam.

I get 6.35 watts/Kg using 2% mechanical losses.
I get 6.42 watts/Kg using 3% mechanical losses. Put some wind in there.