Critical Power Study of GT Winners

[peloton]

Der Kaiser, RoboBasso and Piti say 'Hi' too

All cleans.

 

[BYOP88]

All cleans.

Exactly! I mean those 3 guys all donated blood to help out with the blood shortage that was going on in Spain in 2005/06. But some unscrupulous Doctor withheld the blood and didn't pass it on so Joe and Jane Average could get blood transfusions during operations etc. Der Kaiser, RoboBasso and Piti never doped and never tested positive.

 

[Ripper]

Froome is ridiculous. Between the Tour of Romandie, mid-April 2011 and the Tour de Suisse, June 2011 his FTP permanently increased by almost 20%. This comes from analyzing his TT performances (relative to the rest of the peloton) from 2008 until now.

Choosing only non-prologue and non-mountain time trials, I found that Froome became 4.7 seconds per kilometer faster from mid-2011 until today. If you assume an average TT speed of 50 km/hr, the speed increase works out to ~20% more power.

It's a sudden and permanent increase with no possible explanation other than doping. And that must be some impressive dope, because that is an *enormous* increase.

John Swanson

Good post. Could not agree more with the bolded

 

[Ripper]

none of them are ridiculous. the 2003 could still happen with clean athletes or close to that level for a bit. what can't happen anymore is seeing this after 3 weeks anymore. this alpe dhuez one is early in the tour I know but from 2003 tour I can show videos of late stages where the same happens.

What ... WTF ... are you smoking. As Red just noted, you might have some difficulty convincing someone that these fully loaded attacks, some of which required uphill braking so as not to crash in a switchback, are not ridiculous.

Oh, and Froome is ridiculous and if you look at how quickly everyone goes backwards, his attack was otherworldly.

 

[Ripper]

I'm guessing he may have been tested once or twice during his emergence as a GC contender, if his doping is that enormous wouldnt we be hearing his rivals crying foul?, seeing some failed drug tests?, anything?....instead its the armchair scientists who think they have all the answers, if his doping is that blatant wouldnt WADA love to get their hands on him?....i'll wait until/if he tests positive before resorting to the clinic's default position of claiming doping to explain every decent performance.

To the bolded - I do not think we are talking about decent performances, are we?

 

[Ripper]

I just KNEW someone would argue that Pantani was actually a great TTer. It doesn't change my point in the slightest. He was not nearly as good as, e.g., Ulle, and in any case, there are many other climbers with very high watts/kg values who can be used to make the same point. Muscle does matter.

I am not sure if you are referring to my question about Pantani or not?

Anyhow, he was certainly not the best by any stretch. But I noticed with Pantani and Heras that they suddenly went from climbing very well and TT'ing very poorly (while no doubt still doped to the gills), to improving their TT substantially. Again, compared to Jan and company, they would get beaten, but not by nearly as much. I wondered at the time and still do if they worked more on enhancing strength components of their riding, resulting in possibly a small loss in climbing, but with more blood boosting, almost not noticeable, and an improvement in TT ability. Basically, even smaller climber types being able to dramatically improve TT ability if focusing in the right ways.

Alberto would be another example of that type of trend. He does not seem to TT nearly as well anymore, does he?

 

[Merckx index]

If you already have an estimate of 1-hour power, then CP is redundant, and attempting to infer AWC from it is not sensible.

I don’t understand why you say this. CP is not the same as one hour power, at least according to this analysis, and moreover, the analysis allows one to separate out anaerobic and aerobic components. If you just have a one hour point, you will have a value that probably is not too far from CP, but it still does not allow you to estimate power at shorter periods. Knowing AEC—again, according to this analysis—does permit that.

CP is almost always higher than 1-hour power, sometimes significantly so. How much higher depends on the input durations chosen.

Again, you’re not making sense to me. CP by definition will never be higher than, and almost always will be lower than, one hour power. CP is defined as power that is sustainable over very long periods of time. Obviously power that is sustainable over periods of time longer than one hour can’t be higher than power sustainable over one hour. This is clearly shown in Fig. 1, and it's also obvious from the alternate version you and Ferm seem to prefer, of Pt = CPt + AEC.

Perhaps you mean that CPt is almost always higher than P60t? That would depend on what t was for the measurement of total CP output, but for most values of t, of course.

And if you don't have accurate data from true maximal efforts of appropriate durations, and collected from around similar periods of form, then then to be frank, it's just all GIGO.

Maybe, but until Sky and other teams get serious about providing SRM data, this is all we have.

 

[Alex Simmons/RST]

I don’t understand why you say this. CP is not the same as one hour power, at least according to this analysis, and moreover, the analysis allows one to separate out anaerobic and aerobic components. If you just have a one hour point, you will have a value that probably is not too far from CP, but it still does not allow you to estimate power at shorter periods. Knowing AEC—again, according to this analysis—does permit that.

Again, you’re not making sense to me. CP by definition will never be higher than, and almost always will be lower than, one hour power. CP is defined as power that is sustainable over very long periods of time. Obviously power that is sustainable over periods of time longer than one hour can’t be higher than power sustainable over one hour. This is clearly shown in Fig. 1, and it's also obvious from the alternate version you and Ferm seem to prefer, of Pt = CPt + AEC.

Perhaps you mean that CPt is almost always higher than P60t? That would depend on what t was for the measurement of total CP output, but for most values of t, of course.

Perhaps we are talking at cross purposes, and yes while CP is nominally defined as long duration sustainable power (and not specifically an hour), in reality and in the manner it's typically determined in the literature (i.e. mean maximal power inputs of between 1 and 15-minutes duration are used), it doesn't do a good job of that, instead it routinely over estimates this capability, sometimes substantially.

How much it over estimates is a function of the inputs chosen. If you include a longer duration effort (e.g 20-30 minutes), it will still tend to over estimate what someone can do for an hour or longer, but the gap is narrowed, although estimates of much longer than an hour tend to diverge from reality.

The CP model's domain of validity is from a few minutes up to close to an hour. Once you go outside of those durations, it just doesn't hold water.

OK, so what, why don't we just use longer durations, as per this paper? Well then you start to move further and further away from being able to reliably ascertain AWC, that's why. The linearity of the energy-duration relationship in no longer a valid assumption. A quick glance at half a dozen rider's mean maximal power-duration curves will tell you that.

In any case, if a model suggests nonsensical values, as this one does, then one should question its validity.

Maybe, but until Sky and other teams get serious about providing SRM data, this is all we have.

You mean get serious about Sky providing left leg only Stages derived power, with all the asymmetry errors that brings into the equation.

 

[Gung Ho Gun]

I am not sure if you are referring to my question about Pantani or not?

Anyhow, he was certainly not the best by any stretch. But I noticed with Pantani and Heras that they suddenly went from climbing very well and TT'ing very poorly (while no doubt still doped to the gills), to improving their TT substantially. Again, compared to Jan and company, they would get beaten, but not by nearly as much. I wondered at the time and still do if they worked more on enhancing strength components of their riding, resulting in possibly a small loss in climbing, but with more blood boosting, almost not noticeable, and an improvement in TT ability. Basically, even smaller climber types being able to dramatically improve TT ability if focusing in the right ways.

Alberto would be another example of that type of trend. He does not seem to TT nearly as well anymore, does he?

Basso seems like the prime example to me
Winning Giro TT's in 2005/2006
Lucky if he doesn't lose a few minutes nowadays

 

[thehog]

Using long duration inputs can invalidate the CP model linearity assumption.

And if you don't have accurate data from true maximal efforts of appropriate durations, and collected from around similar periods of form, then then to be frank, it's just all GIGO.

Precisely.

The method is of little importance if the data sources used are flawed or selective as in this case.

For the purposes of looking at the data best to remove the question of doping to one side.

The report details its data source as:

“2. Our own observations of the Grand Tours in 2012-2013, and power computations with a Matlab program CyclingPower.m The details of this program will be published elsewhere. “

Emphasis on the term “our own” and GTs "2012 and 2013".

Because when you look at the data that was omitted from the study its then easy to see how the report came to the conclusions that it did regardless of the method applied and the attempt to get to a single figure representing presumed power.

In essence it’s a comparison of short punchy climbs on short stages in the Vuelta vs. longer drawn out climbs in the Tour.

What is most surprising is author attempts to predict what Horner would be like on longer climbs in either the Tour or the Giro. The problem is he has that data in real life. Horner rode the 2012 Tour and finished in the realm of 1.30-2.30 minutes behind Froome on the few mountain stages. Why estimate when you already have the data? That’s not very smart. Why be so selected and attempt to estimate Horner’s performance when you have that data already?

Therefore omitted from the study:

x Horner 2012 Tour and Horner Gallina 2013 - (Horner 2013 one minute slower than Froome 2012)

x 2013 Tour de France Grand Bornand

x Froome Vuelta 20111 and 2012 including Gallina.

x Contador Vuelta 2012

Thus using theHogs patented “BS-logic systems” and lets remove the question of doping and we are left with the following ACTUAL comparison:

Vuelta’s shorter climbs and stages:
Pena Cabarga 6km (178km), Naraco 6km (177km), Hazallais 7.5km (186km), Angliru 13.2km (142km) author removes (Gallina 7.6km – 155km; Horner 2013 one minute slower than Froome 2011).

Vs.

Tour climbs:
Ventoux 21km (232km), Huez 14km (172km) , Toussuire 18km (148km), La Semnoz 10.7km, (125km), Ax-3 7.8km (195km), Belles Filles 5.9km (199km)

or

Horner vuelta: (6, 6, 7.5, 13.2 = 32.7km) – Total Climbing (4 data points)
(178, 177, 186, 142 = 683km) – Total Stage lengths

Froome Tour (21, 14, 18, 7.8, 5.9, 10.7 = 77.4km) - Total Climbing (6 data points)
(232, 172, 148, 195, 199, 125km = 1071km ) – Total Stage lengths

Diff: 388km / 44.7km

Which is almost 400km difference and 45km of climbing – which of course you’d expect Froome to exhibit a lower watts/p.kg just as Horner did in the 2012 Tour.

In layman’s terms all the study is actually doing is:

INLCUDE Froome Tour on longer climbs and stages 2012 and 2013, REMOVE Froome Vuelta on shorter stages and climb 2012 (and 2011), INCLUDE Horner’s shorter stages and climbs 2013 Vuelta, REMOVE Horner’s Gallina effort at the Vuelta 2013 and INCLUDE Contador short effort on Veriber of 20 minutes and then OVERLAY Indurain performances on longer Tour climbs from 1994 and OMIT Indurain Vuelta climbs from same period (if any).


Forget the method the data set is poor and the author hasn’t clearly stated the data he is actually using. And why predict Horner on longer climbs when you have his data from the 2012 Tour? And what’s with the selective nature of choosing data that fits? (ie Gallina removal).


How anyone was able to draw any conclusions from this research is beyond me. Well I guess if its telling you what you’d like to hear then you would reference the study.

 

[thehog]

Oh and comparing Pena at 500m to the Stelvio at 2500m!? Can't stop laughing.

 

[jw1979]

The study linked is crap. If you have crap data you can't get much that will be meaningful from it.

His estimates for Ryder H. are a joke. FTP of 5.22 w/kg. That's just plain ignorant! Nobody will win a GT with an FTP of 5.22 w/kg. I am embarrassed for the author.

Froome with an FTP of 5.60 w/kg and he's blowing the field away. Is this supposed to be some sort of puff piece put out by Sky that is simultaneously supposed to cast doubt on Horner.

It's really pathetic.

The top guys are doing 6.00 - 6.30 w/kg for an hour when somewhat fresh and about 6.8 - 7.1 w/kg for 20 minutes when not depleted.

It takes 6.65 - 6.80 w/kg for 13-15 minutes to win the uphill TT at southern California's San Dimas Stage Race, and that is a long ways away from a GT winner in Europe! Phil Gaimon would be destroying the Euro peloton if the study's author were correct.

Porte put out a few percent either way of 7.0 w/kg to win the final Paris-Nice TT last year in 19:16. That is consistent with an FTP of about 6.2 w/kg. And he says Contandor was at 5.44 w/kg for FTP. Absurd.

 

[Tyler'sTwin]

Porte put out a few percent either way of 7.0 w/kg to win the final Paris-Nice TT last year in 19:16.

No, it was 6.4 W/kg.

It is known that when Porte won the 9.4km time trial up the Col d'Eze in a little more than 19 minutes to win Paris-Nice in March, he averaged 400 watts. He was then 62.5kg, against his 61kg when he rode his time trial up the Col de la Madone last Sunday. He is still 61kg.

Read more: http://www.smh.com.au/sport/cycling...gun-ability-20130628-2p2n9.html#ixzz2wRMWVsqC

 

[jw1979]

No, it was 6.4 W/kg.



Read more: http://www.smh.com.au/sport/cycling...gun-ability-20130628-2p2n9.html#ixzz2wRMWVsqC

You don't actually believe that, do you? He averaged 400 watts on the dot? And they are going to tell their competitors that? I'm not buying that for one minute that the US domestic peloton's best are stronger than the best riders of the Pro Tour.

Look up what Rory Sutherland did for power in that TT and how far back he was.

 

[thehog]

Looking at those charts some of the input data looks dodgy too.

Forget the input data, the hand selected races is the problem. Why did he omit so much data when it's readily available? i.e. Horner at the Tour 12 & Froome at the Vuelta 12 or 11?

Odd. Comparing 6km climbs at 500m to 20km climbs at 1950m it's not rocket science on the results he got. 15 minutes efforts vs 55 minute efforts at altitude

I thought leaving out Gallina in the Vuelta '13 was a nice touch whereby Froome's time is a full minute faster which he also left out.

Good old modification of data trick

Smart guy. Someone email him and get him here to discuss

 

[Merckx index]

What is most surprising is author attempts to predict what Horner would be like on longer climbs in either the Tour or the Giro. The problem is he has that data in real life. Horner rode the 2012 Tour and finished in the realm of 1.30-2.30 minutes behind Froome on the few mountain stages. Why estimate when you already have the data? That’s not very smart. Why be so selected and attempt to estimate Horner’s performance when you have that data already?

As a guess, maybe for the same reason the study did not use Froome’s times on climbs pre-2011 Vuelta? Horner’s 2013 Vuelta, obviously, was his best performance in a GT. That is the kind of data you want to use.

Obviously there is a trade-off here, or what a cynic would call a no-win situation. If you cull certain climbs because they don't fit certain criteria, you are left with too few data points to have much confidence in slopes and intercepts. I would say the author has erred on that side. But the other side is to use many climbs that may not be representative for various reasons, e.g., see below.

Therefore omitted from the study:

x Horner 2012 Tour and Horner Gallina 2013 - (Horner 2013 one minute slower than Froome 2012)

From the paper: “Stage 14 of the 2013 Vuelta e Espana ended on the Collada de la Gallina. Many riders, amongst who [was] Ivan Basso, had to abandon the stage because of severe under-cooling.”

x 2013 Tour de France Grand Bornand

“An example of data to be rejected is…when…top riders will not go all-out because any time won on the ascent can still be lost on the descent.”

Froome Vuelta 2011 and 2012 including Gallina.

It would be interesting to have the 2011 data, but he did start the race as a domestique, after all. (Same in 2012 TDF, but at least in 2012 he was recognized as a strong rider from the outset, and expected to compete for the podium to the extent that didn’t conflict with riding for Wiggo). He clearly was not at his best in the 2012 Vuelta following the Tour. Yes, I understand that your point is that he still was better than Horner there, but I'm guessing this is why the author did not want to use data from this GT.

Contador Vuelta 2012

Again, not at his best. Neither was he in the 2013 Tour, but that was used as a comparison to 2009.

The top guys are doing 6.00 - 6.30 w/kg for an hour when somewhat fresh and about 6.8 - 7.1 w/kg for 20 minutes when not depleted.

Can you provide some links for this claim? I agree there are some problems with selectivity in this study, and unlike some in this forum I’m not an encyclopedia of data when it comes to climbing times, but offhand I don’t recall anyone doing 7 watts/kg for 20 minutes in recent years.

Smart guy. Someone email him and get him here to discuss

Yes, that would be fun.

 

[thehog]

As a guess, maybe for the same reason the study did not use Froome’s times on climbs pre-2011 Vuelta? Horner’s 2013 Vuelta, obviously, was his best performance in a GT. That is the kind of data you want to use.

Obviously there is a trade-off here, or what a cynic would call a no-win situation. If you cull certain climbs because they don't fit certain criteria, you are left with too few data points to have much confidence in slopes and intercepts. I would say the author has erred on that side. But the other side is to use many climbs that may not be representative for various reasons, e.g., see below.



From the paper: “Stage 14 of the 2013 Vuelta e Espana ended on the Collada de la Gallina. Many riders, amongst who [was] Ivan Basso, had to abandon the stage because of severe under-cooling.”



“An example of data to be rejected is…when…top riders will not go all-out because any time won on the ascent can still be lost on the descent.”

I read the caveats but it doesn't explain why he left out Froome Vuelta 12. He says the data source is "GT 2012 and 2013." And why he left out Horner 12 Tour.

All he really compared was Horner Vuelta 13 to Froome Tour 12 & 13.

Then overlayed a long and mountainous Giro 12 and Indurian Tour 94. Contador Verbier 20 minute effort makes it's appearance also.

Which tells you what? He compared 'shorter climbs and stages' to 'longer climbs and stages'.

The results are exactly as you'd expect. Higher wattages on shorter climbs and lower wattages on longer climbs.

How one would draw out doping or not doping for any of the riders bar Indurian would be a pointless exercise.

 

[Race Radio]

It takes 6.65 - 6.80 w/kg for 13-15 minutes to win the uphill TT at southern California's San Dimas Stage Race, and that is a long ways away from a GT winner in Europe! Phil Gaimon would be destroying the Euro peloton if the study's author were correct.

Phil is hitting 6.3 for 20 minutes these days. There are few guys I would put my hand the fire for but Phil is one of them.

 

[jw1979]

Phil is hitting 6.3 for 20 minutes these days. There are few guys I would put my hand the fire for but Phil is one of them.

He can probably do about 6.0-6.1 w/kg for 40-45 minutes then, with an FTP of about 5.8-5.9 w/kg. I've always thought that 40-45 minutes was the the approximate base time for "Critical Power", then you add the anaerobic work capacity to that.

For instance, most guys fall in the range of having anywhere from 350-600 joules of anaerobic work capacity per kg of lean mass. Say Phil is average here and has 475 joules/kg. Let's pretend he weighs 67 kgs and has 6% bodyfat. That gives him roughly 63 kgs of lean mass. 63 * 475 = 29915, or essentially 30kj of AWC to play with. 30kj is 500 watts for 1 minute. Figure it'll take a minimum of 3.5 minutes to fully burn through the AWC.

6.1*67=409
500/40=8
409-8=401
500/20=25
25+401=426
426/67=6.35
500/14 (length of SDSR TT) = 36
401+36=437
437/67=6.52

So yeah, makes sense he's doing about 6.3 w/kg for 20', as I recall him doing about 448w at 66-67kgs to win SDSR TT in the past, which was about 14:00.

That'd be an FTP of about 5.8-5.9, which is really phenomenal, and believable, but it's not enough to win a GT. I'd say he's roughly .4-.5 w/kg shy of being a GT contender. Not that anyone was claiming he should be winning one, but it underscores how ridiculous it is to say Ryder or Contador had such low FTPs the past few years.

Until you can hyperlink into my neural network, I don't have the time to do someone else's (somewhat pointless) research, sorry Merckx Index. I'm just not that organized.

If Phil puts out roughly 8-10% less power in a 20:00 uphill TT than someone like Porte, we would expect him to be about 5-6% (1:00 - 1:15) slower or thereabouts. Granted, if he's working for someone like Talansky, it's unlikely he'll be fresh enough to show his true capacity and would be expected to be a bit further back.

BTW, Merkcx Index, Rory Sutherland was 2:01 back from Porte and had his power data up. You could look for that online. If Rory was 21:17, Porte 19:16, I'd expect Porte to have put out roughly 12-15% more power, depending on their aerodynamics.

OK, here is one link, but one only because I have to go workout!
http://velonews.competitor.com/2013...-rory-sutherlands-paris-nice-race-data_277749
This sounds reasonable for Rory based on his results domestically that I have power data access to as well.
6.15 * 1.12-1.15 = 6.88 w/kg -7.07 w/kg

6.88 - 7.07 w/kg for roughly 20:00 is consistent historically with the top riders in the world. I would expect nothing different for someone winning Paris-Nice.

 

[Race Radio]

Let's pretend he weighs 67 kgs

64kg....after food poisoning

 

[proffate]

Porte put out a few percent either way of 7.0 w/kg to win the final Paris-Nice TT last year in 19:16. That is consistent with an FTP of about 6.2 w/kg. And he says Contandor was at 5.44 w/kg for FTP. Absurd.

isn't ftp 95% of 20 minute power? Which would mean Porte's FTP is 6.65.

 

[proffate]

For instance, most guys fall in the range of having anywhere from 350-600 joules of anaerobic work capacity per kg of lean mass. Say Phil is average here and has 475 joules/kg. Let's pretend he weighs 67 kgs and has 6% bodyfat. That gives him roughly 63 kgs of lean mass. 63 * 475 = 29915, or essentially 30kj of AWC to play with. 30kj is 500 watts for 1 minute. Figure it'll take a minimum of 3.5 minutes to fully burn through the AWC.

normally body composition is divided into 3 categories, fat free mass (FFM), water, and fat. If you define "lean mass" as everything besides fat, then you're including water weight (bones, bowel contents, etc.). Why would anything besides actual muscle and maybe liver contain work capacity?

Also, Phil is exceptionally lean. 6% bf is an overestimate. Having raced crits with him, he's told me that he can sustain 500 watts for ages but can't hit 800 watts for 30 seconds. So whatever your calculations you use, bear in mind that for Phil, the sanity check is "really really below average AWC".

 

[jw1979]

isn't ftp 95% of 20 minute power? Which would mean Porte's FTP is 6.65.

That's a generalization that doesn't tend to work out for most people. I've found when you triple the amount of time going from 20' to 60' you should expect power to drop by closer to 10%, unless...your AWC is very low, you don't sweat too much, it's fairly cool outside, your motivation is extraordinarily high, and your ability to focus/suffer matches your extraordinary motivation. 60' without a lapse in concentration is a whole nother ball game than 20'. Just ask the guys who try the hour record.

 

[Merckx index]

He can probably do about 6.0-6.1 w/kg for 40-45 minutes then, with an FTP of about 5.8-5.9 w/kg. I've always thought that 40-45 minutes was the the approximate base time for "Critical Power", then you add the anaerobic work capacity to that.

Well, in the link you provided below, for Sutherland, the 20 min. power was 6.1 watts, and the 1 hour or FTP was just 4.8 watts/kg. Going from 6.3 at 20 minutes to 5.8-5.9 at FTP depends a lot on your assumptions about AEC, which I will discuss below. Though I tend to think the 4.8 value does not reflect his best effort, i.e., he wasn't going all out that entire time. If you plug those numbers into the equation used in the paper, you get an estimate of AEC that seems too high.

For instance, most guys fall in the range of having anywhere from 350-600 joules of anaerobic work capacity per kg of lean mass. Say Phil is average here and has 475 joules/kg. Let's pretend he weighs 67 kgs and has 6% bodyfat. That gives him roughly 63 kgs of lean mass. 63 * 475 = 29915, or essentially 30kj of AWC to play with. 30kj is 500 watts for 1 minute. Figure it'll take a minimum of 3.5 minutes to fully burn through the AWC.

In the study discussed in this thread, all the riders were well above 30 kj. E.g., Froome was over 100. Horner, the lowest, was about 45.

6.1*67=409
500/40=8 [Nope, 12.5]
409-8=401
500/20=25
25+401=426
426/67=6.35
500/14 (length of SDSR TT) = 36
401+36=437
437/67=6.52

So yeah, makes sense he's doing about 6.3 w/kg for 20', as I recall him doing about 448w at 66-67kgs to win SDSR TT in the past, which was about 14:00.

That'd be an FTP of about 5.8-5.9, which is really phenomenal, and believable, but it's not enough to win a GT. I'd say he's roughly .4-.5 w/kg shy of being a GT contender. Not that anyone was claiming he should be winning one, but it underscores how ridiculous it is to say Ryder or Contador had such low FTPs the past few years.

It depends on the AEC. Horner, who had the lowest estimated AEC for any of the riders in the study, had a 20 min. power of 6.3 and an estimated FTP of 5.85, in line with your estimate. But other riders had much higher AECs, and a different relationship. E.g., Contador 2009 had a 20 min power of about 6.9, but an FTP of 5.9. Froome has 6.5 and 5.6, respectively. The reason the FTPs seem unreasonably low to you is that the AECs are much higher than you are allowing for. Maybe you think they are unreasonably high, I don’t know.

If Phil puts out roughly 8-10% less power in a 20:00 uphill TT than someone like Porte, we would expect him to be about 5-6% (1:00 - 1:15) slower or thereabouts.

No, power is proportional to climbing time, so he should be 8-10% slower. Unless the gradient is fairly shallow, and wind resistance is significant.

BTW, Merkcx Index, Rory Sutherland was 2:01 back from Porte and had his power data up. You could look for that online. If Rory was 21:17, Porte 19:16, I'd expect Porte to have put out roughly 12-15% more power, depending on their aerodynamics.

OK, so Porte was 10% faster. It was about 5% gradient, so there could have been some wind resistance, meaning that 10% faster means more than 10% difference in power. But there could have been drafting, too, I don't know.

OK, here is one link, but one only because I have to go workout!
http://velonews.competitor.com/2013/...ce-data_277749
This sounds reasonable for Rory based on his results domestically that I have power data access to as well.
6.15 * 1.12-1.15 = 6.88 w/kg -7.07 w/kg

This link gives his 20 min power as 6.1 watts/kg. If you add 10% for Porte you get 6.7 watts/kg., subject to assumption that wind resistance wasn't a factor. This is actually a little less than Contador 2009, who, again, had a calculated FTP of just 5.9. So again, it depends on AEC. Porte could have a very high 20 min power (but not 7.0) and still have an FTP in the range determined in this paper.

So to summarize, your main point was that the FTP values he determined are ridiculously low, and you claimed that the existence of 7.0 watts/kg efforts at 20 min. shows this. I'm not yet convinced that anyone recently has done 7.0. I don't think the Sutherland/Porte data quite establish that, and from what I've heard, Contador at TA was not close to that. More important, though, the author is arguing that FTP can be much lower than 20 min power if AEC is high, thus the example of Contador 2009 or Froome 2013. This is clearly controversial. Alex, following post, says FTP is usually within 90% of 20 min, whereas in this paper the estimates for some riders go much lower.

 

[Alex Simmons/RST]

isn't ftp 95% of 20 minute power? Which would mean Porte's FTP is 6.65.

No, it's not.

The ratio of FTP to 20-minute mean maximal power is a range, usually somewhere in the 89-96% range, with 91-94% being more typical.

There are a range of factors that influence that ratio for any individual.