Power Data Estimates for the climbing stages

[131313]

Must be very very smooth roads for a Crr < 0.004

What were the wind conditions?

keep in mind they were not using full aero kit.

What are guesstimates ranges for assumed inputs; mass, CdA, Crr, wind, air density, and what sort of a range for the W/kg calculation does that make for?

How variable was the gradient over the course? For a course of this duration I usually generate ~ 75 individual segments.

The roads on the that TT were supposedly very smooth. That said, I don't think .30 is that far off or unreasonable. In field testing that my coach has done, he's come up with Crr on-road of .03 for the Records, and if you use Coggan's 1.45 correction factor for roller data, .003 isn't far off either. On rollers they've tested around .0021 or so in the wider size. Regardless, on a HC TT of that distance, a difference of .0005 ends up being 10 seconds. So, it's not going to have a huge impact on the calculation.

To the above post regarding Armstrong's L'alpe TT, the most thorough estimation I've seen on the interwebs that I've seen put it in the range of 6.4 w/kg. I'm guessing that's right about where Nibali was in this one, +/- .2 w/kg.

 

[131313]

True Lance's power from those years was higher than now with Nibali....

BUT what was the 2nd place rider's power from that year (Ullrich). What did Basso do in 2004? What did Mancebo do during those years or Vino...they were all talented dopers. What was the winning TT power at the Tour when Lance left, if I remember Floyd's coach ventura had all of Floyd's power data live and was rambling on sporadically during the TV coverage that year....FTP 400, 6.0 w/kg.

I'm not sure that's actually true regarding Lance's power output. I dug this up from the internets and found it interesting:

http://www.biketechreview.com/index.php/performance/supply/493-la-cant-do-it

I found that while looking for estimations of LA's power output. It's pretty interesting to see the estimated outputs of the different riders, and the incredible increase in LA. And, I believe this was the year LA complained about Mayo and Tyler riding so fast! In hindsight the whole thing is funny to read.

 

[Alex Simmons/RST]

What were the wind conditions?
I would have liked to know, however, from looking at the course it seems unlikely to be a potential pb for calculations.

How variable was the gradient over the course? For a course of this duration I usually generate ~ 75 individual segments.

I don't know if 131313 made a calculation or not., but it's obvious to me that dividing those 9450 m in 75 segments would be gross overkill considering you can't hope for a representative result at better than a 3-4% ! given the lack of knowledge about wind, the effect of rain and the usual suspects.

Overkill? Perhaps. 3-4% would be pretty good going. Add in uncertainly on mass, Crr, variable CdA values and wind vectors for each part of course, then what error range do you think should be quoted?

Published elevation profile via inrng:

 

[Le breton]

Overkill? Perhaps. 3-4% would be pretty good going. Add in uncertainly on mass, Crr, variable CdA values and wind vectors for each part of course, then what error range do you think should be quoted?

Published elevation profile via inrng:

The uncertainty is not on mass per se but on the fraction (cyclist mass/total mass), that's also where the rain could make a small difference (water-logged clothe), another place being the kinetic energy lost to the water "thrown about" by the rider's wheels.

Since I have not seen the stage I don't know about the wind, but as I said, considering all the twisting and turning, I don't see how it could really have a significant effect, although it is still the main cause overall for uncertainty in the calculation (together with the CdA)

 

[Bavarianrider]

Impressive.



https://twitter.com/ammattipyoraily/status/337883648860770305

Horrible calculations, not even close to reality. Nibali was nowhere enar to 6.5

 

[Inquitus]

Nibalis performance is way out of left field, he's never climbed this well or TT'd this well in the past. Maybe its just relative to the poor form of the competition, and makes me perceive it this way, but with his previous and his form this Giro I think he's doping.

If the mountains were left in he'd be winning by a ridic amount by Sun.

 

[Le breton]

Horrible calculations, not even close to reality. Nibali was nowhere enar to 6.5

What does "horrible calculation" refer to? mean? it would be good to post things that can be understood.

As you can see a little bit higher in this thread I posted a calculation for the first part of the climb giving all the elements entering in the result so that people who disagree with it can react constructively. I invite you to have a look at it.

 

[Netserk]

Yes, but 6.0 max is for the LAST CLIMB of a hard mountain stage. IIRC Moncoutié was at 6.2 up AdH in 2004 (TdF)

According to this Moncoutie was 5.84

 

[Red Rick]

Any calculations on the last 3,75 km of Tre Cime?

 

[Netserk]

Any calculations on the last 3,75 km of Tre Cime?

I think they were slow.

 

[Le breton]

I think they were slow.

OF COURSE, at an ave. altitude of 2075 m. power is down by about 9%, and the speed should also be down by almost 9% on such a steep climb.

 

[Netserk]

OF COURSE, at an ave. altitude of 2075 m. power is down by about 9%, and the speed should also be down by almost 9% on such a steep climb.

Relatively to other times on the climb.

 

[Le breton]

Relatively to other times on the climb.

ok
do you have numbers?

 

[whittashau]

Nibalis performance is way out of left field, he's never climbed this well or TT'd this well in the past. Maybe its just relative to the poor form of the competition, and makes me perceive it this way, but with his previous and his form this Giro I think he's doping.

If the mountains were left in he'd be winning by a ridic amount by Sun.

I seem to remember Nibali attacking and gaping riders in the Tour last year, but Froome happened to be supermanish that day. Just like all the other days. And Nibali has always been good in MTTs. Plus theoretically he should be at, or very close to his career peak.

 

[Netserk]

ok
do you have numbers?

No. It was a pure guesstimate.

 

[roundabout]

Di Luca took 22 minutes or so for the last 7ish km in 2007 (from the fork near the lake)

 

[maltiv]

I'm just waiting for some posters to use the Dr Ferrari "VAM to w/kg" method for today's climb, concluding that Nibali went at 7 w/kg

(The Ferrari-method overstates w/kg enormously on steep climbs)

 

[Netserk]

No. It was a pure guesstimate.

Apparently a bad one at that. Only 31 seconds slower than Danilo in '07.

 

[Lanark]

I'm just waiting for some posters to use the Dr Ferrari "VAM to w/kg" method for today's climb, concluding that Nibali went at 7 w/kg

(The Ferrari-method overstates w/kg enormously on steep climbs)

Ferrari method had the lowest estimate:

Stage 20. Tre Cime di Lavaredo (3.0 km, 12.37 %). Vincenzo Nibali. DrF: 5.52 W/kg. CPL: 5.71 W/kg. rst: 5.72 W/kg. BCR: 5.81 W/kg.

 

[Le breton]

I'm just waiting for some posters to use the Dr Ferrari "VAM to w/kg" method for today's climb, concluding that Nibali went at 7 w/kg

(The Ferrari-method overstates w/kg enormously on steep climbs)

7 W/kg at 2075 meters would mean 7.6 at sea-level.
The Ferrari-method overstates w/kg enormously on steep climbs

I didn't know he had a method.
Anyway on such steep climbs you don't need to be much of an expert to get a good estimate of the power.

However, the climb being so short it's essential to have the altitude well determined.

 

[Ferminal]

I'm just waiting for some posters to use the Dr Ferrari "VAM to w/kg" method for today's climb, concluding that Nibali went at 7 w/kg

(The Ferrari-method overstates w/kg enormously on steep climbs)

It's actually the reverse... Anywhere less than around 6-6.5 and anything over 10-11 will underestimate. Goldilocks around 7-9%.

 

[L'arriviste]

Just got my copy of the La Preuve par 21 magazine by Antoine Vayer, the owner of Cyclisme Dopage, Le Monde contributor JP de Mondenard and LA Confidentiel contributor Frédéric Portoleau.

It's a study of Tour de France performances down the years using the calculation methods developed principally by Portoleau.

Excellent stuff, here's a few pics I took:

"Suspect", "Miracle", "Mutant"

This is the French edition that's now on release. English version, to be called 21 Counts, is due out very shortly. I think you can pre-order it from their site though. http://www.alternativeditions.com/21-counts/

I don't want to give all the best bits away but if I said only one rider was given a "clean bill of health"... ?

 

[Alex Simmons/RST]

Anyone predicting times for the TDS St9 ITT?

If post hoc estimates are so popular, how about some predictions on the time up climbs?

 

[Netserk]

Anyone predicting times for the TDS St9 ITT?

If post hoc estimates are so popular, how about some predictions on the time up climbs?

32-34 minutes.

A 30' time = ~6.65W/kg

EDIT: This is for the climb alone.

 

[mustang]

Anyone predicting times for the TDS St9 ITT?

If post hoc estimates are so popular, how about some predictions on the time up climbs?

Depends on wind ,52-53min. Organizer predicted 46min