Power Data Estimates for the climbing stages

[Turner29]

The **** is that post supposed to tell me? Ullrich was doping in 1996. Post climbing results from pre-1996 if you want to make a point.

That was Ullrich's first Tour.

 

[Turner29]

I think some of our forum posters are doping too...

 

[kingjr]

That was Ullrich's first Tour.

Yes, and? What does that mean? Riis winning that Tour showed us that you certainly didn't need to be a climbing-prodigy to make a GT-podium during that time if you just took enough of good old EPO.

 

[BYOP88]

Yes, and? What does that mean? Riis winning that Tour showed us that you certainly didn't need to be a climbing-prodigy to make a GT-podium during that time if you just took enough of good old EPO.

Change Riis and replace it with Wiggins or Froome, still believable?

 

[kingjr]

Change Riis and replace it with Wiggins or Froome, still believable?

I will repeat what I said, we know that Riis and Ullrich doped back then, we know zilch in that regard about Froome and Wiggins. We have suspicious performances that deserve to be questioned I totally agree with that, but other than that we have nothing at all.

 

[Turner29]

Well, the actual weight of the rider does not make much difference on the estimate of watts/kg needed to obtain a certain speed on a certain slope. This is both an adventage and a disadventage of the method, but I'll come back to this at the end of my post.

The watts needed to obtain a certain speed on a certain slope is linearly related to the weight of the object, as one can see in one of the more simplistic formula's used to estimate the watts for cyclists:

Watts = total mass * slope * speed in meters/sec * 9.8 m/sec^2

As you can see here, the estimated amount of watts covaries lineairly with the total mass of the rider + equipement. For example, if a 40kg object requires 200watts to achieve 30km/h on a certain slope, then a 20kg object would only require a 100 Watts to achieve that same speed on the same slope. However, if you now devide the watts needed by the mass, you would see that both objects require 5 watts per kg to obtain that speed on that slope. In more mathematical terms, it would look like this:

Watts = total mass * slope * speed in meters/sec * 9.8 m/sec^2

W/kg = Watts / total mass
= (total mass * slope * speed in meters/sec * 9.8 m/sec^2) / total mass
= slope * speed in meters/sec * 9.8 m/sec^2

So even if the weight varies, the estimate of watts/kg stays the same and that's why you can use a standardized weight of 70 kg in the calculations, as the actual weight drops out of the equations. This is the adventage of the method.

What's the disadventage?

Well, the method assumes that any difference in weight between riders is due to a difference of effective body mass (i.e. muscles). Imagine a rider of 100 kg going up Alp D'Huez with 10 watts/kg, producing a massive, impossible 1000 watts in a record Alp D'Huez time of 20 minutes. Now imagine the guy losing half his weight (all fat), going up Alp D'Huez equaling his record time of 20 minutes. As the weight drops out of the equation of w/kg, he has still produced 10watts/kg, but the total amount of watts is less, only 500 watts. Both performances are equal in terms of w/kg, but not in total watts produced. The second performance was worse than the first, despite the same w/kg estimate.

Good for back of the envelope but too inaccurate for any critical analysis.

Using a model that I find very accurate, a 70 kg rider with 10 kg of equipment, 80 kg total mass will require 400 watts to climb Alpe d'Huez in 41'15" with no wind, at speed of 19.2 km/hr or 5.33 m/s.

This is 5.0 w/kg of total mass, or more commonly 5.71 w/kg of rider mass.

Your method estimates 4.28 w/kg.

 

[Turner29]

I will repeat what I said, we know that Riis and Ullrich doped back then, we know zilch in that regard about Froome and Wiggins. We have suspicious performances that deserve to be questioned I totally agree with that, but other than that we have nothing at all.

Until Armstrong went on Oprah, people said the same about Armstrong.

As I said in another posting, Froome et al on Sky use gray method doping, one of which is Thyroid Hormone -- telltale signs of such were visibly obvious yesterday.

Brailsford's pompous rants over the last year should be enough evidence, since many of his statements now are in direct contradiction to when he did not have to produce results.

 

[the sceptic]

Ok look at Froome's climbing times on mountain stages and ITT's pre-Vuelta 2011 and compare them from then to now.

sounds like a nice project for you after you did the same with Porte. do it

 

[BYOP88]

I will repeat what I said, we know that Riis and Ullrich doped back then, we know zilch in that regard about Froome and Wiggins. We have suspicious performances that deserve to be questioned I totally agree with that, but other than that we have nothing at all.

So we knew that Jan doped back then, but did we have any proof? As far I remember Jan like Froome and Wiggins, has never tested positive. I guess it's easy to look back 16-17 years now we have some recent information and say 'I knew it'. For me Jan is more believable as a GT winner/making it on the podium than Froome or Wiggins and we now know what Jan did to get there.

 

[Turner29]

OF course not
At the level of a a very few kilos it really doesn't matter.

On Alpe d'Huez, each kilogram of added weight costs 30 seconds in time. Conversely, to maintaining the same speed requires 5 more watts per kg of added weight.

One kg either way race day won't matter much, three is critical.

 

[BYOP88]

sounds like a nice project for you after you did the same with Porte. do it

I have to complete the Porte thing first. So some time this week I'll be looking at all his mountain results in week long races too.

 

[Alex Simmons/RST]

Apparently it was a headwind along the final, flatter part. Haven't seen the route to know what that meant for the rest of the climb.

Exactly, and there was quite a wind and while it clearly impacts differently depending on which part of the climb you are on. I wasn't there nor do I have the actual data and so I cannot say.

But then nobody else can either unless they are able to supply data on the air movement, hence W/kg numbers from ascent times without showing the error range is grossly misleading.

I tried to find some wind data on line, and a historical record to see what conditions were like in say 2003 (it was a very hot summer that year although the worst was after the tour I think) but after 5-minutes without luck I CBA for this rather pointless exercise.

The W/kg numbers quoted could well be significantly under or over estimated. Let alone factor in the variability of the gradients. Given the way the flags were horizontal, I'd put estimates in a +/-1.0 W/kg range at the very least until better data can be provided.

IOW, the estimates are essentially useless for comparison to anything but ascents performed under the same conditions.

What we do know is the relative performance of the riders on the day, that is all.

 

[Alex Simmons/RST]

Well, the actual weight of the rider does not make much difference on the estimate of watts/kg needed to obtain a certain speed on a certain slope. This is both an adventage and a disadventage of the method, but I'll come back to this at the end of my post.

The watts needed to obtain a certain speed on a certain slope is linearly related to the weight of the object, as one can see in one of the more simplistic formula's used to estimate the watts for cyclists:

Watts = total mass * slope * speed in meters/sec * 9.8 m/sec^2

Simplistic but useless for the purposes used by many in this forum (i.e. as a dopeometer).

Discussion of human performance relates to body mass only (i.e. the rate energy supply expressed as watts per kilogram of body mass) while the energy demand relates to the total mass of the bike + rider + kit and the other important energy demand factors such as rolling resistance, and air resistance which is clearly affected by drafting and especially by wind.

Unless one can know both body mass and total system mass, it's just another error in the performance estimates, although one that's likely smaller than the other errors introduced by wind.

 

[Dear Wiggo]

Exactly, and there was quite a wind and while it clearly impacts differently depending on which part of the climb you are on. I wasn't there nor do I have the actual data and so I cannot say.

Speed is not the only variable being considered. The wind would have been affecting everyone pretty much the same.

 

[BigBoat]

What we do know is the relative performance of the riders on the day, that is all.

That's true, it is possible that the numbers are off, and Evan's real avg. power on Axe 3 Domaines was less than 5.35 w/kg. So Froome could have done less than 6.5 w/kg. And Froome also could have done more, just like Evans might have done more.

But as we start to compile a list of Froome climbs I think we will get a good picture of his sustainable power. We have his Madone "32 mins" and now his Ax-3 Domaines (23:14).

At some point when one keeps getting: 6.4 w/kg, 6.5 w/kg, 6.3 w/kg, 6.6 w/kg, etc. the likelihood that his power is vastly different starts to fall off.

 

[BigBoat]

Edit: If i dope myself i may get 50% less power than the worst TDF clean rider. The only scientific method to prove that X doped with substance Y is to find Y trace in tests.

I'm really amazed that people take seriously this "scientific" numbers.

Power numbers mean a lot when comparing talented riders. A talented blood doper in grand Tour cycling cannot be beaten (in my opinion). The riders we are comparing are or are among the best in the world. Its unlikely there's someone out there so incredible that they cleanly overcome one of the most talented riders in the world, who is doping... Not likely!

That being said it isn't wrong for me to seriously suspect someone of doping, especially after nearly all Tour winners in the last 25 years have been busted!

 

[Alex Simmons/RST]

Power numbers mean a lot when comparing talented riders. A talented blood doper in grand Tour cycling cannot be beaten (in my opinion). The riders we are comparing are or are among the best in the world. Its unlikely there's someone out there so incredible that they cleanly overcome one of the most talented riders in the world, who is doping... Not likely!

That being said it isn't wrong for me to seriously suspect someone of doping, especially after nearly all Tour winners in the last 25 years have been busted!

A talented rider
A talented doper
A talented responder

Important differences I'd have thought. Which do you mean?

 

[Alex Simmons/RST]

That's true, it is possible that the numbers are off, and Evan's real avg. power on Axe 3 Domaines was less than 5.35 w/kg. So Froome could have done less than 6.5 w/kg. And Froome also could have done more, just like Evans might have done more.

But as we start to compile a list of Froome climbs I think we will get a good picture of his sustainable power. We have his Madone "32 mins" and now his Ax-3 Domaines (23:14).

At some point when one keeps getting: 6.4 w/kg, 6.5 w/kg, 6.3 w/kg, 6.6 w/kg, etc. the likelihood that his power is vastly different starts to fall off.

And is why I suggest simply sticking to the trends comparing ascent times for the same climb. W/kg estimates are nothing more than pub chat fodder.

 

[Alex Simmons/RST]

Speed is not the only variable being considered.

Wind is the most significant variable in any calculation of power from climbing speed outside of mass and gradients of the various sections, so ignore it at your estimation peril, especially when it's obvious there's quite a lot of it about.

The wind would have been affecting everyone pretty much the same.

Which is why I said:

What we do know is the relative performance of the riders on the day, that is all.

 

[Tonton]

I think some of our forum posters are doping too...

You're right Turner. I'm having a beer as we speak, like Floyd Landis did (or was it Jack Daniel's), so I can out perform myself tomorrow. Cheers!

 

[Dear Wiggo]

Wind is the most significant variable in any calculation of power from climbing speed outside of mass and gradients of the various sections, so ignore it at your estimation peril, especially when it's obvious there's quite a lot of it about.

Saying it's not the only variable is not the same as ignoring it.

As for my peril?

You are taking this far too seriously.

 

[nickel999]

You're right Turner. I'm having a beer as we speak, like Floyd Landis did (or was it Jack Daniel's), so I can out perform myself tomorrow. Cheers!

Yes, its the Champion system

http://www.cyclingnews.com/news/floyd-landis-backed-gran-fondo-set-for-this-weekend

 

[Turner29]

"VN: And that information would be available to your rivals?
DB: It’s our competitive advantage [Brailsford compared it to a journalist sharing a scoop with rivals]. It’s not how the world works. We want to be open and transparent, but that’s why the biological passport is actually a good thing. You have an agreed panel of experts, you agree to a collective decision, they know how to analyze it. If we evolved and worked on that principle, then it’s something we’d be interested in.

If people could truly understand and interpret power, what it is and what it isn’t, and it isn’t what a lot of people think it is. You get all kinds of readings. We look at power numbers every day, and you get these anomalies, you get these quirks, if things are not quite calibrated correctly, or if something else is wrong. All of those things need to be taken into account, just like the biological passport. There is a fruitful area of debate and opportunity in terms of what power data could provide, I am very pro-that, but just releasing it in general is not the right way to go."

He is blowing smoke...

"VN: People seem to draw conclusions based on the numbers, but are they correct conclusions?
DB: At some point in time, people have to accept that performances are going to move forward. If we always hold back, and say, here is some data from people who were doping, then if we draw a line, we can then deduce that anyone crossing that line must also be doping. Well, that’s false. They do not have to be doping, because the whole human race moves forward. At some point in time, clean performances will surpass the doped performances in the past. You cannot use that as a rule to say that means that they are doping."

The Sports Science guys covered this fairly well:

http://www.sportsscientists.com/2013/07/clean-performances-to-surpass-doped.html

Decades Dave, not years.



VN: What kind of variables or conditions can influence power readings?
DB: Add temperature, wind, road conditions, normalized VAM, normalized power; we know aerodynamic drags of our riders, and even with that it’s hard, so when people start saying, we’ll just assume this and that, come on, guys, if you have to have true scientific rigor, you would know what you’re doing is not scientifically.

This pseudo-scientist did not realize that wind, road conditions and normalized VAM can effect power readings.

 

[acoggan]

That's true, it is possible that the numbers are off, and Evan's real avg. power on Axe 3 Domaines was less than 5.35 w/kg. So Froome could have done less than 6.5 w/kg. And Froome also could have done more, just like Evans might have done more.

But as we start to compile a list of Froome climbs I think we will get a good picture of his sustainable power. We have his Madone "32 mins" and now his Ax-3 Domaines (23:14).

At some point when one keeps getting: 6.4 w/kg, 6.5 w/kg, 6.3 w/kg, 6.6 w/kg, etc. the likelihood that his power is vastly different starts to fall off.

Let's say, for sake of argument, that we knew definitively that Froome's power during TTs is, say, 6.1 W/kg, and that he produces a bit more than that while climbing (for shorter durations). Does that prove that he is doping, or not?

 

[Turner29]

Let's say, for sake of argument, that we knew definitively that Froome's power during TTs is, say, 6.1 W/kg, and that he produces a bit more than that while climbing (for shorter durations). Does that prove that he is doping, or not?

At 6.1 w/kg for a TT, even somebody a skeptical as I am in a court of law would have to say no.