Power Data Estimates for the climbing stages

[Alex Simmons/RST]

Re: Re:

I used my own in order to observe the range of possible outcomes.

What range of outcomes do you get?
What assumptions are you using?

The main variables that I change are weight, wind strength, drafting time, and sometimes a ply with the CDA as well. But the first three are the most important one. I didn't do it for this one, but for Froome's climb in PSM I get the following range:

% ---------W/Kg-------Watts

0%---------5.84-------386
10%-------6.01-------400
20%-------6.06-------404
30%-------6.11-------407
40%-------6.15-------410
50%-------6.19-------413
60%-------6.23-------416
70%-------6.26-------418
80%-------6.30-------421
90%-------6.36-------425
100%------6.54-------440

Absolute minimum is 5.84 w/kg.
Most likely scenario would be around the 50% which is 6.19 w/kg.
My weight rage was 65.5-68 kg. That should cover all possible outcomes.

Thanks.
What happens with wind strength variations, using, for instance, your 50% draft?

 

[Alex Simmons/RST]

I had a chance to update the chart with the revised 1991 times and have added a little extra data as well:
http://alex-cycle.blogspot.com.au/2015/07/alpe-dhuez-tdf-fastest-ascent-times.html

The individual riders are shown in this image:
http://1.bp.blogspot.com/-wBLVXRsQE-Y/VbcEvvN4wGI/AAAAAAAABzE/DeIGfAu2S-w/s1600/Alpe%2Bd%2527Huez%2Btop%2B5%2Bascents%2B1982-2015.jpg

 

[webvan]

Impressive work! Any idea what time Hinault and Lemond posted in 86?

 

[Alex Simmons/RST]

Re:

Impressive work! Any idea what time Hinault and Lemond posted in 86?

All I'm doing is creating charts based on data collated by https://twitter.com/ammattipyoraily and adding a bit of extra info.

The data I used originally was from his top 200 ascent times and updated 1991 times in more recent postings, so I can only presume they didn't make the top 200 cut. If anyone has video footage to put a clock on them, it would be fun to add them to the charts.

Also I added another table, this one with local weather conditions, including prevailing wind:

Comments in the blog item.

 

[Merckx index]

I believe the 1991 times are uncertain because it’s not clear where the timing started from. Using one start vs. the other accounts for the 45”. I don’t think anyone really knows for certain which times are correct. But even if we use the faster times—Ammati—they are not faster than contemporary times (defined as 2008-15, the passport era). We know that EPO was available in 1991, and if you look at the difference in times vs. 1987-89, they are faster, which is consistent with some EPO use. So I think we can conclude that riders in the passport era are doing ADH at least as fast as in the early part of the EPO era, albeit definitely slower than the peak.

Average of five fastest times from 1987-1989 (EPO probably not used): 42:06
Average of ten fastest times in 1991 (EPO used by some riders): 40:24 (41:09)*
Average of ten fastest times from 1994-97 (no 50% rule, no EPO test): 38:03
Average of ten fastest times from 2001-06 (no blood transfusion test, no passport): 38:44
Average of ten fastest times from 2008-2015 (passport era): 40:25

*using the slower times by Vetoo et al.

There are of course complicating factors like racing tactics, differences in sample size, etc.

In training Gesink can sustain 455W for 20 minutes on a climb in top form

At what weight? Going by the 68 kg listed at one source, that would be 6.7 W/kg. That is very suspicious even for 20 minutes.

 

[pmcg76]

Re:

Impressive work! Any idea what time Hinault and Lemond posted in 86?

Always read that Hinault/LeMond were around 48 minutes in 86 which is very slow but then Hinault had been on the attack from the Galibier and was alone until joined by LeMond before the Croix de Fer where they dropped everyone and came to Alpe d'Huez with a huge lead, they were already number 1-2 on GC by miles.

 

[pmcg76]

Re: Re:

Impressive work! Any idea what time Hinault and Lemond posted in 86?

All I'm doing is creating charts based on data collated by https://twitter.com/ammattipyoraily and adding a bit of extra info.

The data I used originally was from his top 200 ascent times and updated 1991 times in more recent postings, so I can only presume they didn't make the top 200 cut. If anyone has video footage to put a clock on them, it would be fun to add them to the charts.

Also I added another table, this one with local weather conditions, including prevailing wind:

Comments in the blog item.

Alex, this is not your fault but the time for Fignon in 87 is wrong. Fignon started the climb 2 minutes in front of Herrera who passed Fignon before the finish so cannot be so close. I think someone somewhere assumed Fignon was in the leading bunch at the foot of Alpe d'Huez.

I think the 87 climb is very interesting at it is the fastest ascent in the pre EPO era. 41.50 Herrera

The facts, stage 20 Villard-de-Lans to Alpe d'Huez 201km.
Climbs en-route: Cucheron 2,Coq 1, Laffrey 1, Alpe d'Huez
The back-ground: Herrera was out of contention for GC but was desperate for a stage win. However a large group was 6 minutes up the road so a stage win was highly unlikely.
The stage was preceded by the Mont Ventoux TT on stage 18, and the hilly stage 19 to Villard-de-Lans which was raced at full gas when Fignon/Mottet attacked in the feed zone in an effort to regain time. Yellow jersey Bernard missed the break so the pace was full on.

The tactical play-out on the day
A group of 20-30 favourites arrive at foot of Alpe d'Huez together. Within the first KM, this is down to 4 riders, Herrera, Delgado, Roche & Lejarreta. They were paced briefly by a blond team-mate of Herrera who then attacks and only Delgado can follow but drops in the next km. Somewhere along the ascent Delgado re-passes Herrera who in-turn re-passes Delgado. A gap opens but Delgado regains the wheel but never relays Herrera and is dropped again about 2-3km from the finish. There is almost zero pacing or drafting during the entirety of Herrera's ascent. When Herrera first attacks, you can see him gobbling up the riders from the break.

Contrast that with the tactics/drafting from last Saturday and it makes an interesting comparison.

Quintana 39.22
Herrera 41.50
@2.28

For funsies, a certain Paul Kimmage finished 2 seconds in front of a certain Miguel Indurain that day.

106 Paul Kimmage @24.21
107 Miguel Indurain @24.23

 

[Alex Simmons/RST]

Re: Re:

Alex, this is not your fault but the time for Fignon in 87 is wrong. Fignon started the climb 2 minutes in front of Herrera who passed Fignon before the finish so cannot be so close. I think someone somewhere assumed Fignon was in the leading bunch at the foot of Alpe d'Huez.

Thanks, yes it gets a little difficult before more contemporary ascents and naturally I'm plotting based on the data sources used.

There are many ascents of AdH that are not in the list, and that's because none made it into vetooo's original top 200 ascent times list. I don't know if anyone has such data on all those other years, or at least good enough video to ascertain it.

I tried to watch youtube video of 1992 ascent (Hampsten et al) but it cuts out of chunk of the climb from the video. It seems to cut from being on the flat approach road to being on turn 17.

When I first started plotting this stuff 5 years ago, before I learned of vetooo's lists, I first used data from Wikipedia, and noted comments about the different timing points used, so direct comparisons were always going to be tricky. Hence in the chart linked I left off Pantani's climb times as it was not clear the data was directly comparable.

 

[Alex Simmons/RST]

Re:

I believe the 1991 times are uncertain because it’s not clear where the timing started from. Using one start vs. the other accounts for the 45”. I don’t think anyone really knows for certain which times are correct. But even if we use the faster times—Ammati—they are not faster than contemporary times (defined as 2008-15, the passport era). We know that EPO was available in 1991, and if you look at the difference in times vs. 1987-89, they are faster, which is consistent with some EPO use. So I think we can conclude that riders in the passport era are doing ADH at least as fast as in the early part of the EPO era, albeit definitely slower than the peak.

Average of five fastest times from 1987-1989 (EPO probably not used): 42:06
Average of ten fastest times in 1991 (EPO used by some riders): 40:24 (41:09)*
Average of ten fastest times from 1994-97 (no 50% rule, no EPO test): 38:03
Average of ten fastest times from 2001-06 (no blood transfusion test, no passport): 38:44
Average of ten fastest times from 2008-2015 (passport era): 40:25

*using the slower times by Vetoo et al.

There are of course complicating factors like racing tactics, differences in sample size, etc.

Keep in mind the data I have is missing rides that did not appear in vetoo's original top 200 list. The are many ascents of AdH that are not in the list and would affect averages, e.g 1992.

AdH was climbed during TdF in the following years since 1980 (original winner):
1980 Joop Zoetemelk (Pays Bas)
1981 Peter Winnen (Pays-Bas)
1982 Beat Breu (Suisse)
1983 Peter Winnen (Pays-Bas)
1984 Luis Herrera (Colombie)
1986 Bernard Hinault (France)
1987 Federico Echave (Espagne)
1988 Steven Rooks (Pays-Bas)
1989 Gert-Jan Theunisse (Pays-Bas)
1990 Gianni Bugno (Italie)
1991 Gianni Bugno (Italie)
1992 Andrew Hampsten (USA)
1994 Roberto Conti (Italie)
1995 Marco Pantani (Italie)
1997 Marco Pantani (Italie)
1999 Giuseppe Guerini (Italie)
2001 Lance Armstrong (USA)
2003 Iban Mayo (Espagne)
2004 Lance Armstrong (USA)
2006 Frank Schleck (Lux)
2008 Carlos Sastre (Espagne)
2011 Pierre Rolland (France)
2013 Christophe Riblon (France)
2015 Thibaut Pinot (France)

 

[Tonton]

Re: Re:

For funsies, a certain Paul Kimmage finished 2 seconds in front of a certain Miguel Indurain that day.

106 Paul Kimmage @24.21
107 Miguel Indurain @24.23

That's before BigMig contracted Bilharzia. We know the rest of the story...

Very fast time for Nairito, who also beat BigMig '91 and '95 times by 23" and 6".

 

[Alex Simmons/RST]

Also, bike weights are probably ~2kg less in current era than in 1991. This review is an example or how bikes have changed over that time, although as with anything, there will be individual variations:
http://www.bikeradar.com/au/road/gear/article/tour-de-france-winning-bikes-34375/

As a guide, up an 7.9% grade, 2kg heavier bike means a 400W, 68kg, 5.9W/kg* rider will go ~ 0.42km/h slower than on the lighter bike. On AdH for instance that's 50 seconds slower.

Or to attain the same speed, the rider with heavier bike requires an extra 9.7W, an increase of 0.14W/kg (from 5.88W/kg to 6.03W/kg).

* this is power to body mass only

 

[pmcg76]

Re:

Also, bike weights are probably ~2kg less in current era than in 1991. This review is an example or how bikes have changed over that time, although as with anything, there will be individual variations:
http://www.bikeradar.com/au/road/gear/article/tour-de-france-winning-bikes-34375/

As a guide, up an 7.9% grade, 2kg heavier bike means a 400W, 68kg, 5.9W/kg* rider will go ~ 0.42km/h slower than on the lighter bike. On AdH for instance that's 50 seconds slower.

Or to attain the same speed, the rider with heavier bike requires an extra 9.7W, an increase of 0.14W/kg (from 5.88W/kg to 6.03W/kg).

* this is power to body mass only

Alex, any way to factor in drafting in terms of time?

 

[Alex Simmons/RST]

Re: Re:

Also, bike weights are probably ~2kg less in current era than in 1991. This review is an example or how bikes have changed over that time, although as with anything, there will be individual variations:
http://www.bikeradar.com/au/road/gear/article/tour-de-france-winning-bikes-34375/

As a guide, up an 7.9% grade, 2kg heavier bike means a 400W, 68kg, 5.9W/kg* rider will go ~ 0.42km/h slower than on the lighter bike. On AdH for instance that's 50 seconds slower.

Or to attain the same speed, the rider with heavier bike requires an extra 9.7W, an increase of 0.14W/kg (from 5.88W/kg to 6.03W/kg).

* this is power to body mass only

Alex, any way to factor in drafting in terms of time?

Yes, but it depends somewhat on the race strategy employed.

Long answer but here goes:

Firstly, it's a little easier to think in terms of wattage saved when in the draft. IOW wattage estimates made from ascent speeds can be made that have an allowance for drafting. Some do this although I'm not sure what method they use. I would reduce their effective CdA by an amount typical for drafting.

Wind is still a much bigger unknown variable though, so let's assume dead calm for now.

If we assume drafting provides a 20% to 30% effective reduction in CdA, then at this sort of elite power/weight, gradient and speed, it's a 7.5W to 11W saving.

So a reduction of 0.1W/kg to 0.15W/kg required to maintain elite climbing speeds for the duration of draft.

In terms of how much extra speed can be gained? That's pretty tricky.

2 scenarios:

1. Protected rider saves power while drafting and rides below their power limit for the expected duration of the climb, then they can increase power above average for balance of climb when going solo. That wouldn't be an optimal pacing strategy to achieve the lowest time, although it is likely to be a less risky strategy.

2. To climb in the shortest time possible, it requires the protected rider be riding at their limit (mean maximal power) for the expected total duration of the climb, and hence the lead rider(s) need to be riding at a slightly higher W/kg than their protected rider's threshold, until the lead rider(s) cracks part way up the climb. Then the protected rider finishes off the climb, still at their mean maximal power for the climb duration but at a slightly slower speed because they no longer have a draft.

Of course such a strategy may or may not be possible since there are many other tactical considerations. For starters there are other competitors that may choose to attack and break rhythm, or indeed have higher W/kg. It's a strategy that requires a team that's "all for one", and as such tends to nullify attacks since presumably the other team's leaders are also riding at their limits too and not really in a position to up the pace much. Attacking is itself a risky strategy, and not reacting to attacks is often a smart choice from a physiological and physics sense. Psychologically though it's a different game. The climbs are about winning, and/or gaining time OR not losing time and/or minimising time losses.

Modelling the fastest time attainable by such a team paced effort and ignoring tactical racing challenges (think Italian pursuit TTT where it's time of the final rider only) would be quite a fun optimisation modelling challenge requiring quite a good understanding of each rider's power-duration curve and physical properties of the riders.

But let's say for example a rider gets a draft for half the climb from team mate(s) that are riding at 0.1 - 0.15 W/kg more than the protected rider's power limit for the whole climb, then at the half way point the lead rider(s) crack, and the lead rider finishes the climb off solo (but at a slower speed).

The time saving up a climb like AdH over a solo effort would be something like 20-28 seconds.

It would require a well drilled team to know how to execute such a pacing strategy. The more team mates that can take such turns before cracking and the deeper into the climb team mates can keep up such an effort, the greater the time benefit for the protected rider.

 

[pmcg76]

Re: Re:

Also, bike weights are probably ~2kg less in current era than in 1991. This review is an example or how bikes have changed over that time, although as with anything, there will be individual variations:
http://www.bikeradar.com/au/road/gear/article/tour-de-france-winning-bikes-34375/

As a guide, up an 7.9% grade, 2kg heavier bike means a 400W, 68kg, 5.9W/kg* rider will go ~ 0.42km/h slower than on the lighter bike. On AdH for instance that's 50 seconds slower.

Or to attain the same speed, the rider with heavier bike requires an extra 9.7W, an increase of 0.14W/kg (from 5.88W/kg to 6.03W/kg).

* this is power to body mass only

Alex, any way to factor in drafting in terms of time?

Yes, but it depends somewhat on the race strategy employed.

Long answer but here goes:

Firstly, it's a little easier to think in terms of wattage saved when in the draft. IOW wattage estimates made from ascent speeds can be made that have an allowance for drafting. Some do this although I'm not sure what method they use. I would reduce their effective CdA by an amount typical for drafting.

Wind is still a much bigger unknown variable though, so let's assume dead calm for now.

If we assume drafting provides a 20% to 30% effective reduction in CdA, then at this sort of elite power/weight, gradient and speed, it's a 7.5W to 11W saving.

So a reduction of 0.1W/kg to 0.15W/kg required to maintain elite climbing speeds for the duration of draft.

In terms of how much extra speed can be gained? That's pretty tricky.

2 scenarios:

1. Protected rider saves power while drafting and rides below their power limit for the expected duration of the climb, then they can increase power above average for balance of climb when going solo. That wouldn't be an optimal pacing strategy to achieve the lowest time, although it is likely to be a less risky strategy.

2. To climb in the shortest time possible, it requires the protected rider be riding at their limit (mean maximal power) for the expected total duration of the climb, and hence the lead rider(s) need to be riding at a slightly higher W/kg than their protected rider's threshold, until the lead rider(s) cracks part way up the climb. Then the protected rider finishes off the climb, still at their mean maximal power for the climb duration but at a slightly slower speed because they no longer have a draft.

Of course such a strategy may or may not be possible since there are many other tactical considerations. For starters there are other competitors that may choose to attack and break rhythm, or indeed have higher W/kg. It's a strategy that requires a team that's "all for one", and as such tends to nullify attacks since presumably the other team's leaders are also riding at their limits too and not really in a position to up the pace much. Attacking is itself a risky strategy, and not reacting to attacks is often a smart choice from a physiological and physics sense. Psychologically though it's a different game. The climbs are about winning, and/or gaining time OR not losing time and/or minimising time losses.

Modelling the fastest time attainable by such a team paced effort and ignoring tactical racing challenges (think Italian pursuit TTT where it's time of the final rider only) would be quite a fun optimisation modelling challenge requiring quite a good understanding of each rider's power-duration curve and physical properties of the riders.

But let's say for example a rider gets a draft for half the climb from team mate(s) that are riding at 0.1 - 0.15 W/kg more than the protected rider's power limit for the whole climb, then at the half way point the lead rider(s) crack, and the lead rider finishes the climb off solo (but at a slower speed).

The time saving up a climb like AdH over a solo effort would be something like 20-28 seconds.

It would require a well drilled team to know how to execute such a pacing strategy. The more team mates that can take such turns before cracking and the deeper into the climb team mates can keep up such an effort, the greater the time benefit for the protected rider.

Ok, thanks Alex.

Based on your examples, I would imagine that Quintana did not gain much time by the drafting he had on Alpe d'Huez. Maybe a few seconds when following the pace at the bottom of the climb and then when drafting Anacona for a km.

 

[Dekker_Tifosi]

Re:

I believe the 1991 times are uncertain because it’s not clear where the timing started from. Using one start vs. the other accounts for the 45”. I don’t think anyone really knows for certain which times are correct. But even if we use the faster times—Ammati—they are not faster than contemporary times (defined as 2008-15, the passport era). We know that EPO was available in 1991, and if you look at the difference in times vs. 1987-89, they are faster, which is consistent with some EPO use. So I think we can conclude that riders in the passport era are doing ADH at least as fast as in the early part of the EPO era, albeit definitely slower than the peak.

Average of five fastest times from 1987-1989 (EPO probably not used): 42:06
Average of ten fastest times in 1991 (EPO used by some riders): 40:24 (41:09)*
Average of ten fastest times from 1994-97 (no 50% rule, no EPO test): 38:03
Average of ten fastest times from 2001-06 (no blood transfusion test, no passport): 38:44
Average of ten fastest times from 2008-2015 (passport era): 40:25

*using the slower times by Vetoo et al.

There are of course complicating factors like racing tactics, differences in sample size, etc.

In training Gesink can sustain 455W for 20 minutes on a climb in top form

At what weight? Going by the 68 kg listed at one source, that would be 6.7 W/kg. That is very suspicious even for 20 minutes.

he's 70 kg actually. Not as skinny as in his first pro years

 

[Escarabajo]

Re: Re:

Ok, thanks Alex.

Based on your examples, I would imagine that Quintana did not gain much time by the drafting he had on Alpe d'Huez. Maybe a few seconds when following the pace at the bottom of the climb and then when drafting Anacona for a km.

FWIW, I made the calculation for Quintana drafting 50% and Quintana exposed 100% and we have the following:

No drafting: 6.22 watts
50% drafting: 6.08 watts.
Difference: 0.14 watts/kg

In time if I set the bar at 6.08 watts/kg then I get the following:

40:08

If I put 2 kg more then:

41:05

That's for 50% drafting for Quintana's size. Herrera maybe a little bigger but we get an idea.

That is a difference of 1:43 between the two.

The scenario for Quintana is no wind. Not sure what the conditions for Herrera were for his time.

 

[Escarabajo]

Re: Re:

I used my own in order to observe the range of possible outcomes.

What range of outcomes do you get?
What assumptions are you using?

The main variables that I change are weight, wind strength, drafting time, and sometimes a ply with the CDA as well. But the first three are the most important one. I didn't do it for this one, but for Froome's climb in PSM I get the following range:

% ---------W/Kg-------Watts

0%---------5.84-------386
10%-------6.01-------400
20%-------6.06-------404
30%-------6.11-------407
40%-------6.15-------410
50%-------6.19-------413
60%-------6.23-------416
70%-------6.26-------418
80%-------6.30-------421
90%-------6.36-------425
100%------6.54-------440

Absolute minimum is 5.84 w/kg.
Most likely scenario would be around the 50% which is 6.19 w/kg.
My weight rage was 65.5-68 kg. That should cover all possible outcomes.

Thanks.
What happens with wind strength variations, using, for instance, your 50% draft?

These numbers were calculated on 60% drafting

The percentages above means the probability of that power event to happened. So 10% means that there is a 90% probability that all power numbers for the rider will be above that power (6.01).

 

[pmcg76]

Re: Re:

Ok, thanks Alex.

Based on your examples, I would imagine that Quintana did not gain much time by the drafting he had on Alpe d'Huez. Maybe a few seconds when following the pace at the bottom of the climb and then when drafting Anacona for a km.

FWIW, I made the calculation for Quintana drafting 50% and Quintana exposed 100% and we have the following:

No drafting: 6.22 watts
50% drafting: 6.08 watts.
Difference: 0.14 watts/kg

In time if I set the bar at 6.08 watts/kg then I get the following:

40:08

If I put 2 kg more then:

41:05

That's for 50% drafting for Quintana's size. Herrera maybe a little bigger but we get an idea.

That is a difference of 1:43 between the two.

The scenario for Quintana is no wind. Not sure what the conditions for Herrera were for his time.

Does those figures factor in the difference in bike weight?

 

[Escarabajo]

Re: Re:

Ok, thanks Alex.

Based on your examples, I would imagine that Quintana did not gain much time by the drafting he had on Alpe d'Huez. Maybe a few seconds when following the pace at the bottom of the climb and then when drafting Anacona for a km.

FWIW, I made the calculation for Quintana drafting 50% and Quintana exposed 100% and we have the following:

No drafting: 6.22 watts
50% drafting: 6.08 watts.
Difference: 0.14 watts/kg

In time if I set the bar at 6.08 watts/kg then I get the following:

40:08

If I put 2 kg more then:

41:05

That's for 50% drafting for Quintana's size. Herrera maybe a little bigger but we get an idea.

That is a difference of 1:43 between the two.

The scenario for Quintana is no wind. Not sure what the conditions for Herrera were for his time.

Does those figures factor in the difference in bike weight?

The 41:05 does. I added the 2 kg in that last calculation. That's why it went from 40:08 to 41:05.

 

[carton]

Re: Re:

Impressive work! Any idea what time Hinault and Lemond posted in 86?

Always read that Hinault/LeMond were around 48 minutes in 86 which is very slow but then Hinault had been on the attack from the Galibier and was alone until joined by LeMond before the Croix de Fer where they dropped everyone and came to Alpe d'Huez with a huge lead, they were already number 1-2 on GC by miles.

LeMond has said he was pretty confident he could've put minutes into Hinault had he wanted to. And Hinault wasn't going full gas either.

 

[Alex Simmons/RST]

Re: Re:

I used my own in order to observe the range of possible outcomes.

What range of outcomes do you get?
What assumptions are you using?

The main variables that I change are weight, wind strength, drafting time, and sometimes a ply with the CDA as well. But the first three are the most important one. I didn't do it for this one, but for Froome's climb in PSM I get the following range:

% ---------W/Kg-------Watts

0%---------5.84-------386
10%-------6.01-------400
20%-------6.06-------404
30%-------6.11-------407
40%-------6.15-------410
50%-------6.19-------413
60%-------6.23-------416
70%-------6.26-------418
80%-------6.30-------421
90%-------6.36-------425
100%------6.54-------440

Absolute minimum is 5.84 w/kg.
Most likely scenario would be around the 50% which is 6.19 w/kg.
My weight rage was 65.5-68 kg. That should cover all possible outcomes.

Thanks.
What happens with wind strength variations, using, for instance, your 50% draft?

These numbers were calculated on 60% drafting

The percentages above means the probability of that power event to happened. So 10% means that there is a 90% probability that all power numbers for the rider will be above that power (6.01).

Do you account for wind conditions in those probabilities?

 

[simoni]

Thanks for your input on the last few points guys. Its very interesting to the uninformed such as myself (and very refreshing to see proper information sharing, discussion and debate without hyperbole and personal agenda getting in the way).

 

[Escarabajo]

Re: Re:

Do you account for wind conditions in those probabilities?

Yes.
A calibration for Gesink gave me an average head wind of 5.5 kph using 50% drafting time. The net average headwind for Gesink would be around 11 kph for the time that he was exposed. And this is just an approximation.
For Froome I used a range starting from -2 kph up to 25 kph as a net headwind for the time that they were exposed. This yields a different average for the whole climb once we take the drafting into account, but at least I covered all my potential outcomes with these ranges. The distribution that I picked for this range was triangular with a most likely value around 11 kph which was the number used for Gesink.
I let the probabilistic (Monte Carlo) program run and I get the array of potential outcomes in Watts per kilogram that I already presented earlier.
It is hard to get the actual net wind speed data by section. That's why Gesink's data is so important. The net head wind calculation is very important but the drafting time is just measured from what we saw in the television.
Hope all this helps.

 

[Alex Simmons/RST]

Re: Re:

Do you account for wind conditions in those probabilities?

Yes.
A calibration for Gesink gave me an average head wind of 5.5 kph using 50% drafting time. The net average headwind for Gesink would be around 11 kph for the time that he was exposed. And this is just an approximation.
For Froome I used a range starting from -2 kph up to 25 kph as a net headwind for the time that they were exposed. This yields a different average for the whole climb once we take the drafting into account, but at least I covered all my potential outcomes with these ranges. The distribution that I picked for this range was triangular with a most likely value around 11 kph which was the number used for Gesink.
I let the probabilistic (Monte Carlo) program run and I get the array of potential outcomes in Watts per kilogram that I already presented earlier.
It is hard to get the actual net wind speed data by section. That's why Gesink's data is so important. The net head wind calculation is very important but the drafting time is just measured from what we saw in the television.
Hope all this helps.

Yes. Thanks.

Has Gesink's Pioneer power meter been verified for reliable accuracy?

 

[SeriousSam]

Escarabajo, that's great stuff. That's exactly what I wanted to get around to doing once I have the time to learn the physics involved: Assign probability distributions to all the input variables that reflect everything we know then propagate through using the equations from physics and obtain a probability distribution for w/kg.

The only thing missing is a graph of the posterior pdf of w/kg. Can you post one?