Power Data Estimates for the climbing stages

[Parrot23]

Was that froome? I thought it was the south african fellow, augustyn or something like that, I remember the stage you mean.

Yes, you're right. Good catch.

http://www.cyclingnews.com/news/augustyn-wants-to-be-a-gc-contender

On Froome in 2008 Tour (his first Tour), I found this:

http://www.guardian.co.uk/sport/2008/jul/28/cycling.tourdefrance

"Froome was one of only four Barloworld riders to finish in Paris - and the highest placed, in 84th. He even briefly escaped in a four-man break on the Champs-Elysées...."

"Froome shone on the Alpe-d'Huez stage, confirming his reputation as a climber by surviving for a while in the company of Denis Menchov before finishing a creditable 31st at the summit. "I'd have liked to have been at the front more but I'm happy to finish my first Tour, especially in such difficult circumstances," he said."

Also see CN's caption of pic on Alpe d'Huez stage in 08 Tour, mentioning his altitude background: "Barloworld's Froome showed that he has talent in the mountains and his Kenyan high altitude background comes in handy."

http://autobus.cyclingnews.com/phot...s/2008/tour08/tour0817/1160_Froome_Huez_PhSpt

 

[Parrot23]

No it should be higher.

....Stopping and starting from low speed again takes more energy everything else being equal.

Are you saying that Froome's average watts/kg for the whole climb (as opposed to wattage peaks and troughs) should be higher than Cobo's etc. because his pacing was more variable?

I may have misunderstood you, but if that's correct, his speed up the climb should be faster than Cobo's because his average watts/kg were higher (his total elapsed time on the climb should be lower).

Not sure, then, why riders ride their own pace on climbs where possible to avoid blowing up from variable pacing (i.e. way above red zone, then back down again briefly, etc.). They know that their avg. watts/kg = speed up the climb will be higher/faster at the smoother pace.

Again, I may have misunderstood what you were saying.

 

[halamala]

is cobo 69kg?

6.3 is pretty impressive. If that is the word.
Of course the leadup to the climb wasn't too difficult.

According to several sources Cobo's weight is 69 kg.

http://www.revistaciclismoenruta.co...el-bisonte_id20559/introduccion_id219303.html

http://en.wikipedia.org/wiki/Juan_Jose_Cobo

http://www.sportal.de/sportal/generated/profile/tdf/cobo_juanjose.html


We have had a great discussion today. I'll be back on Monday. Good night.

 

[Escarabajo]

Are you saying that Froome's average watts/kg for the whole climb (as opposed to wattage peaks and troughs) should be higher than Cobo's etc. because his pacing was more variable?

I may have misunderstood you, but if that's correct, his speed up the climb should be faster than Cobo's because his average watts/kg were higher (his total elapsed time on the climb should be lower).

Not sure, then, why riders ride their own pace on climbs where possible to avoid blowing up from variable pacing (i.e. way above red zone, then back down again briefly, etc.). They know that their avg. watts/kg = speed up the climb will be higher/faster at the smoother pace.

Again, I may have misunderstood what you were saying.

I don't know if it should be higher than Cobo's. There is no way of knowing that. I only said that it should be higher than assuming a constant speed on the whole climb.

All I am saying that the constant accelerating and decelerating on the climbs hurts the riders, especially big ones, because they have to employ more energy. The problem with introducing the kinetic energy variable in the power equation is that the speed can not be considered constant and therefore it will become an unknown. At that point you would have a second order differential equation, because of the speed variable, that could only be solved with numerical methods. In some papers where they have powerful computers and all controlled data they can afford to do that. They can even solve the power equation by segments which we don't do either here.

I am always puzzled by how much this kinetic energy portion affects the calculations. Especially in guys like Contador or Pantani that accelerate on the climbs all the time.

In other words it pays to always go at your own pace and avoiding accelerations and decelerations.

 

[kielbasa]

But that goes back to my original question....

Does a rider generate less power spinning a lower gear versus mashing a higher gear assuming speeds are the same?

Are you saying the power is the same - spinning versus mashing?
Seems to me Mashing would require more power, everything else being equal.

Or at least spinning a lower gear would be more efficient on some climbs.
More efficient is good.
More efficient = more power it appears.

That said, I hope Cobo gets busted on the rest day and the Jersey goes to Froome lol.

You're confusing power and force and for some reason you're making a correlation between cadence and efficiency. I can only guess who the culprit might be.

Like I said before, the only thing that cadence is directly related to is comfort. If it feels most comfortable, then that's your best cadence. Efficiency is something completely different and yes, more of it is good. As to whether it's even possible to increase it through training, that is still up for scientific debate.

 

[kielbasa]

Yes, same wattage per the equations.

But spinning watts and mashing watts affect a rider differently.

If Wiggins had a bailout gear today - he would have generated more watts by finishing a bit quicker.

Heck, if he reconned the climb a few extra times, he would have probably finished quicker with higher wattage too.

Oh well, live and learn

Yes, mashing Watts requires more Newtons of force, than spinning Watts. But what feels more comfortable depends on the rider and probably his muscle type. The theory is that using less force is less fatiguing, but the cardiovascular system is more stressed by the higher cadence (frequency of movement).

Still, the self-selected cadence is the best option, provided that the proper gearing is available. Which brings us back to the ridiculousness of the Angliru climb and whether riders used the gears that allowed them to use the best self-selected cadence that would result in optimal power output.

 

[Le breton]

.............
According to close family friend, Dr. M. Ferrari, LA had to adopt high cadence as through contracting cancer in 1996 he had lost power.

I would assume Ferrari would have said force, not power!!!!!!!!!!!¨¨

 

[Hors-Catégorie]

Vuelta a Espana 2011, Stage 15, Final climb, Angliru

From 12.0 Km remaining to mountain points banner 0.5 Km remaining = Distance 11.5 Km

Juan Jose Cobo

Elevation / Höhenmeter [m] : 1194 m
Distance / Streckenlänge [Km] : 11.5 Km
Time in seconds / Fahrzeit in Sekunden [sec] : 2353 = 39 min 13 sec = 39:13
Weight rider / Gewicht Fahrer [kg] : 69 kg
Weight bicycle, clothes etc. / Gewicht Fahrrad [kg] : 8 kg

Grade / mittlere Seigung : 10.3 %
Average speed / mittlere Geschwindigkeit : 17.5 Km/h
Total weight / Gesamtgewicht : 77.0 kg

Power : 430.6 Watt
Power / kg : 6.2 Watt / kg

From 12.0 Km remaining to the finish line = Distance 12.0 Km [last 500 m is descent]

Juan Jose Cobo

Elevation / Höhenmeter [m] : 1194 m
Distance / Streckenlänge [Km] : 12.0 Km
Time in seconds / Fahrzeit in Sekunden [sec] : 2402 = 40 min 02 sec = 40:02
Weight rider / Gewicht Fahrer [kg] : 69 kg
Weight bicycle, clothes etc. / Gewicht Fahrrad [kg] : 8 kg

Grade / mittlere Seigung : 9.9 %
Average speed / mittlere Geschwindigkeit : 17.9 Km/h
Total weight / Gesamtgewicht : 77.0 kg

Power : 425.1 Watt
Power / kg : 6.1 Watt / kg

Source: [ http://www.rst.mp-all.de/bergauf.htm ]

With all due respect to You halamala. How can one calculate an accurate figure with http://www.rst.mp-all.de/bergauf.htm calculator.

It does not take into account wind conditions. Does this calculator take into account aerodynamic resistance based upon height and weight using a standard road bike. The rolling resistance of the tires. Rider accelerations or decelerations. The exact weight of Cobo, his clothing and bike. How can one obtain an accurate figure.

 

[rgmerk]

Still, the self-selected cadence is the best option, provided that the proper gearing is available. Which brings us back to the ridiculousness of the Angliru climb and whether riders used the gears that allowed them to use the best self-selected cadence that would result in optimal power output.

Hmmm.

I played around with some numbers and I reckon that even a world-class climber could have have been left undergeared for the Angliru on a 36/28.

A 68 kg climber on a 7 kg bike putting out 450 watts (6.6 W/kg, more than they can sustain over the entirety of a climb) will do about 9.4 kilometres an hour on a 23% slope (the steepest bit of the Angliru).

That works out to a cadence of 57 rpm on a 36/28. Mashing, in other words.

Maybe the 20+% stretches are so short, that the riders are confident that they can pump out enough power over those short periods to keep the legs turning - or, alternately, they can afford to mash through those.

But given 34-tooth front chainrings and 29, 30 and 32-tooth options for the rear are available, why wouldn't you give yourself the option of a bailout gear?

 

[webvan]

Yes, I'd really like to hear what Wigans has to say about his gearing or about the Angliru in general. Cobo certainly made it look easier than the Zoncolan.

 

[Fergoose]

Cobo's numbers should be more accurate than Froomes' because he had a steadier pace. Froome's numbers are more variable because of its constants accelerations and decelerations.

I can't say I detected these "constant accelerations and decelerations" unless you mean that to include getting out of your saddle briefly on a steeper section? Maybe they happened after Moto 2 & 3 were lost; because prior to that he was with Wiggins who was riding (as far as possible given varying gradients) a constant tempo.

Also faintly amusing that the first thing requested after the stage is finished is Froome's data rather than Cobo's. Maybe we can still ask for the calculations of who finished third behind Piepolli & Cobo back in the 2008 TdF?

 

[JibberJim]

But given 34-tooth front chainrings and 29, 30 and 32-tooth options for the rear are available, why wouldn't you give yourself the option of a bailout gear?

Wiggins rides OSymmetric rings, which are not available in a 34, the smallest available are the smallest he had.

He probably should've ridden a round 34 though in retrospect.

 

[ChrisE]

You tacitly allude to your wonder boy, Lance Armstrong, as the precedent example of the statements in bold?

According to close family friend, Dr. M. Ferrari, LA had to adopt high cadence as through contracting cancer in 1996 he had lost power.

But you rightly claim a high or low cadence approach produces the same wattage from a rider then Dr. Ferrari's claim was part of the developing LA collection of myths.

One only has to look at the discredited claims by fellow Texan and physiologist Dr. Ed Coyle in his paper "Improved muscular efficiency displayed as Tour de France champion matures" , that contrary to Ferrari's justification for LA's improvement through high cadence LA was improving his power.

To run endurance high cadence you must enhance your aerobic power. Chemical assistance?

OK, so why don't they just run a 53/12 and be done with it?

 

[Polish]

OK, so why don't they just run a 53/12 and be done with it?

It is not humanly possible to ride up the Angliru in a 53/12 in 43 minutes.
Maybe an ExtraTerrestial could however.
Beldar on a Bianchi.

And if the ET did mash up the mountain in a 53/12 in 43 minutes, he would show the same power numbers as Cobo.

So if you want to find a way to distinquish extraterrestials from mere humans, do not depend on the power test.

 

[Swede1]

I can't say I detected these "constant accelerations and decelerations" unless you mean that to include getting out of your saddle briefly on a steeper section? Maybe they happened after Moto 2 & 3 were lost; because prior to that he was with Wiggins who was riding (as far as possible given varying gradients) a constant tempo.

Also faintly amusing that the first thing requested after the stage is finished is Froome's data rather than Cobo's. Maybe we can still ask for the calculations of who finished third behind Piepolli & Cobo back in the 2008 TdF?

Frank Schleck and he was only about 30 seconds behind them I think.

 

[Merckx index]

Does a rider generate less power spinning a lower gear versus mashing a higher gear assuming speeds are the same?

It depends on where you measure the power. Power or force was originally defined as that necessary to move a unit weight (1 kg) a unit vertical distance (1 m) in a unit of time (1 sec). That’s why VAM is an appropriate measure of power. VAM is vertical meters per hour. The weight factor is missing, which means VAM is proportional to watts/kg rather than watts.

So two riders who climb the same vertical distance in the same time put out the same watts/kg, as measured by the final outcome of that power. If one weighs more than the other, he is putting out more total watts, but the same watts/kg. This is true regardless of their riding styles.

But if you measure power as it actually generated from the body—which SRAM and other technology attempts to do—you get a more physiological value, because there may be losses between the force put out by the body and the actual lifting force (rolling resistance, air resistance, chain friction, which formulas like Hala's attempt to take into account). By definition, these losses will be increased by riding with lower efficiency. Mashing generally is a less efficient way to ride (depending on just what cadence one considers mashing), meaning more of the output is lost to these other factors. For example, if a rider slows way down on a steep climb, and has to overcome inertia in order to get up to a higher speed subsequently, rolling resistance becomes greater at that point. There may also be greater losses because of the mechanics of leg movement. These latter ones cannot be taken into account by any common formula (see below).

I don't agree with that. If the more variable pacing hypothesis is correct on Froome's part, it would mean his average watts should be lower than a rider riding his own pace alone. The physiological demands are more stressful/less energy efficient with changes in pace, so the average mechanical output in watts should be lower (because he's "burning more matches", more high octane/anaerobic, etc.) not higher--taken in toto/on average.

I think what Escarabajo means is that if Froome is burning matches that are in effect wasted in less efficient riding, his power is somewhat underestimated. Some of the watts he is generating go to heat loss when if used more efficiently they could have gone to a faster pace. Again, it depends on where you measure the power. Parrot is correct that the mechanical output is lower because of this waste, but at some point upstream in the body the power output is greater. The loss occurs somewhere between the two.

It could occur between the movements of the body and the lifting force on the road, in which case you could say that Froome is putting out more watts and wasting some, or the loss could come somewhere between the energy production in muscle cells and the resulting mechanical movement of the muscles. In that case, you could say Froome is putting out less watts, though he has the potential cellular physiology to put out more.

Vaughters just tweeted (at me ) that he thinks the numbers for Cobo + Froome here might be a tad high and they're closer to 6.0 and 5.7. And he'll try and work it out on Tuesday.

Using just the standard VAM formula, and Hala’s numbers, Cobo comes in at 6.02 watts/kg. But that is still very high. His VAM was 1827. VAMs over 1800 are very rare (for a climb this long), and generally thought to be unachievable except by doping. Even more remarkable, as another poster pointed out, there was a near false-flat in this climb, where VAM necessarily drops. IOW, a rider can generally climb a hill with a constant gradient faster than one with a changing gradient. Though the average gradient is the same, the constant gradient allows more efficient riding.

 

[William H]

Angliru is more than 10% average. Of course you're going to get a high VAM.

 

[ChrisE]

It is not humanly possible to ride up the Angliru in a 53/12 in 43 minutes.
Maybe an ExtraTerrestial could however.
Beldar on a Bianchi.

And if the ET did mash up the mountain in a 53/12 in 43 minutes, he would show the same power numbers as Cobo.

So if you want to find a way to distinquish extraterrestials from mere humans, do not depend on the power test.

Polish, I would like velodude to explain why somebody cannot mash a 53x12 up a mountain if it takes the same power as a smaller gear.

 

[Escarabajo]

I can't say I detected these "constant accelerations and decelerations" unless you mean that to include getting out of your saddle briefly on a steeper section? Maybe they happened after Moto 2 & 3 were lost; because prior to that he was with Wiggins who was riding (as far as possible given varying gradients) a constant tempo.

Also faintly amusing that the first thing requested after the stage is finished is Froome's data rather than Cobo's. Maybe we can still ask for the calculations of who finished third behind Piepolli & Cobo back in the 2008 TdF?

Because of two things, or maybe three:

1- To me Cobo is a known business. I am entitled to my opinion. He already has his past.

2- Froome's weight.

3- Froome's history or lack of it. On that respect I am ignorant, but people keep digging stuff from the past to proof that he always had it. Maybe you know more than I do in that respect. Please, be my guest and tell us more.

Thanks.

 

[Fergoose]

I'm quite keen to keep this excellent thread free from off topic clutter. You can find my thoughts on Froome in the "No way Sky is clean?" thread.

I was more interested in why you repeatedly stated Froome was "constantly accelerating and decelerating" up the Angliru (as I'd be inclined to agree such an ascent would use more energy than a steady tempo). I'm not knocking your point, merely looking for clarification as that wasn't my interpretation of Froome's ride at all.

 

[Benotti69]

I'm quite keen to keep this excellent thread free from off topic clutter. You can find my thoughts on Froome in the "No way Sky is clean?" thread.

I was more interested in why you repeatedly stated Froome was "constantly accelerating and decelerating" up the Angliru (as I'd be inclined to agree such an ascent would use more energy than a steady tempo). I'm not knocking your point, merely looking for clarification as that wasn't my interpretation of Froome's ride at all.

well he was behind his team leader, Wiggins, many times during the last parts of the stage and there is no way Wiggin's was breaking his tempo for Froome to get past and set the pace so it would have been Froome who would have had to accelerate past Wiggins to then set the tempo. it also appeared when Wiggins cracked that Menchov and Poels went past, Froome was trying to drag Wiggin's back to Menchov and Poels, then we had no shots from Moto2/3 and i see in photos that Froome was leading Mencov and Poels up the final kiolmetres in what appears a bid to limit his losses.

 

[Escarabajo]

I'm quite keen to keep this excellent thread free from off topic clutter. You can find my thoughts on Froome in the "No way Sky is clean?" thread.

I was more interested in why you repeatedly stated Froome was "constantly accelerating and decelerating" up the Angliru (as I'd be inclined to agree such an ascent would use more energy than a steady tempo). I'm not knocking your point, merely looking for clarification as that wasn't my interpretation of Froome's ride at all.

It depends on what you watch on the TV. Your opinion is different to mine. We both are entitled to an opinion. I also think that you are a little too sensitive on this Froome's thing. I really don't have anything against him. I know nothing about him. I would not want to make something up just for the fun of it. I thought is was too obvious by watching him in the TV.

In fact the way he rides reminded me of Robert Alban at some instances.

 

[rgmerk]

Mean wattage is not the whole story

Mean (average) watts calculations are unaffected by accelerations and decelerations. If Rider A produces 400 watts for 20 minutes and 200 watts for 20 minutes, their average wattage over the 40 minutes is 300 watts, the same as rider B who maintains a constant 300 watts for 40 minutes.

However, rider A has clearly worked a lot harder than rider B.

Coggan has a statistic called normalized power which attempts to take this into account. A normalized power figure is designed to indicate an equivalent psychological "cost" to maintaining a constant wattage.

Regarding wind, the very steepness of Angliru makes it less of a factor, particularly if calculations exclude the last 500 metres past the KOM point. Furthermore, IIRC there was fog on the mountain, indicative of very light winds.

Yes, VAM is likely to be highest on very steep slopes like the Angliru, as very little energy is wasted pushing air out of the way, or to road friction. Drafting has a lesser effect on the calculations than on less steep mountains, for the same reason.

What would be very helpful is if there is some public power data from one of the riders from the Vuelta, for whom an estimate can be calculated and the VAM-based calculations checked against.

 

[Fergoose]

It depends on what you watch on the TV. Your opinion is different to mine. We both are entitled to an opinion. I also think that you are a little too sensitive on this Froome's thing. I really don't have anything against him. I know nothing about him. I would not want to make something up just for the fun of it. I thought is was too obvious by watching him in the TV.

In fact the way he rides reminded me of Robert Alban at some instances.

Sorry if I came across as sensitive somehow, I was merely trying to grasp an unchallenged argument of how his w/kg should be higher as I didn't think passing Wiggins a couple of times would really mean his figures should be pushed up. I'll leave it to the experts to decide if it should impact on the figures and not lose any sleep over it!

Thank you Benotti for the attempted explanation, I'll assume that was what Escarabajo was driving at.

 

[halamala]

Hautacam, Tour 2008: Cobo climbed 6.1 W/kg

Cobo and Piepoli @ Hautacam, Tour 2008

Tour de France 2008, Stage 10, Final climb Hautacam

Juan Jose Cobo

Elevation / Höhenmeter [m] : 1069 m [Source: Letour.fr]
Distance / Streckenlänge [Km] : 14.4 Km
Time in seconds / Fahrzeit in Sekunden [sec] : 2351 = 39 min 11 sec = 39:11
Weight rider / Gewicht Fahrer [kg] : 69 kg
Weight bicycle, clothes etc. / Gewicht Fahrrad [kg] : 8 kg

Grade / mittlere Seigung : 7.4 %
Average speed / mittlere Geschwindigkeit : 22.0 Km/h
Total weight / Gesamtgewicht : 77.0 kg

Power : 423.1 Watt
Power / kg : 6.1 Watt / kg

Source: [ http://www.rst.mp-all.de/bergauf.htm ]

[ Leonardo Piepoli (54 kg*) : 351.6 Watt , 6.5 Watt / kg ]

* = http://en.wikipedia.org/wiki/Leonardo_Piepoli