• We're giving away a Cyclingnews water bottle! Find out more here!

Power Data Estimates for the climbing stages

Page 136 - Get up to date with the latest news, scores & standings from the Cycling News Community.
miguelindurain111 said:
According to French pseudoscientists Froome's numbers on his legendary clean break were

- Finestre 64 min at 5.14 W/kg (including 28 min at 5.57 W/kg)
- Sestrieres 21 min at 5.29 W/kg
- Jaffereau 25 min at 5.43 W/kg

https://mobile.twitter.com/lapreuvepar21/status/1001165650210025473
The link provides just watts, the W/kg values seem to assume 67 kg, which is probably close to the correct weight. Also, according to the link, Finestre was done at 360 watts, slightly higher than Siestrieres, and corresponding to 5.37 W/kg. Anyway, as I’ve noted before, these values are quite close to Floyd’s in the Morzine stage. Assuming a body weight of 68 kg, his average power over the first 30 minutes was 5.90 W/kg, and his power for the last two hours (not including descents) was 5.35 W/kg. The actually pedaling in the last two hours was apparently about 105 minutes, which is close to the 110 minutes Froome spent climbing Finestre, Sestrieres and Bardo.
 
Jun 26, 2017
228
0
0
Re:

Merckx index said:
miguelindurain111 said:
According to French pseudoscientists Froome's numbers on his legendary clean break were

- Finestre 64 min at 5.14 W/kg (including 28 min at 5.57 W/kg)
- Sestrieres 21 min at 5.29 W/kg
- Jaffereau 25 min at 5.43 W/kg

https://mobile.twitter.com/lapreuvepar21/status/1001165650210025473
The link provides just watts, the W/kg values seem to assume 67 kg, which is probably close to the correct weight. Also, according to the link, Finestre was done at 360 watts, slightly higher than Siestrieres, and corresponding to 5.37 W/kg.
No. The links provides normalized (etalon) watts, meaning they are multiplying W/kg by 70 kg. Moreover, they are guessing Froome's weight to be 68 kg. See Vayer's tweet, just above the linked tweet.
 
Re: Re:

carton said:
Alex Simmons/RST said:
In terms of sensitivity of rolling resistance to W/kg estimates, even a doubling of a typical road Crr assumption would add ~0.2W/kg or an error in W/kg estimation of about 3%. That's on say a 10% climb.
On this calculator, just the difference between riding on an asphalt road and on rough tarmac implies a doubling of the Crr:

https://www.cyclingpowerlab.com/PowerComponents.aspx

So according to that calculator, and given standard assumptions otherwise, a 67 kg rider (75kg including bike + kit) would have to put out around 5.1W / kg to go 14.9 km/h on a 10% grade assuming ashpalt road Crr (.004), losing 12W due to rolling restistance, vs. 5.3W/kg, losing 24W due to rolling restance, assuming rough tarmac CRR. So that matches up pretty much perfectly with your calculation. However, that assumption, according to the calculator would still just be rough tarmac. A thoroughly uneducated guess, extrapolating from that and given my limited experience cross country mountain biking, would be that humid sterrato could imply a further doubling of Crr. So closer to 48W according to that calculator, implying a power output of 5.66 W / Kg.

Sure, that's just a guess. And Finestre is partially paved. But I do still think there might be some friction losses given the surface and the conditions on the day that most estimates are leaving out.
Cool, yes the actual Crr is an unknown, and is of course variable so we are really dealing with entire section or entire climb averages.
 
Re: Re:

miguelindurain111 said:
No. The links provides normalized (etalon) watts, meaning they are multiplying W/kg by 70 kg. Moreover, they are guessing Froome's weight to be 68 kg. See Vayer's tweet, just above the linked tweet.
IOW, rather than post the raw watts, they post (watts X 70/68). I’ve never understood why they do it this way. At least Allan Lim posted Floyd’s raw watts.
 
Re: Re:

Merckx index said:
miguelindurain111 said:
No. The links provides normalized (etalon) watts, meaning they are multiplying W/kg by 70 kg. Moreover, they are guessing Froome's weight to be 68 kg. See Vayer's tweet, just above the linked tweet.
IOW, rather than post the raw watts, they post (watts X 70/68). I’ve never understood why they do it this way. At least Allan Lim posted Floyd’s raw watts.
It's not normal I tell you...
:lol:
 
Sep 6, 2016
463
0
0
Re:

SeriousSam said:
So what's the time adjusted for the trackstanding towards the end?
41:15 total. Quintana finished 47 seconds back after being 1:00 down with 3km to go. I think if they rode hard that gap would’ve gone out to 1:10 or before the climb flattened out. I think Quintana probably would’ve lost 1:15 if everyone went full gas. So many 30 seconds lost? I think the times are comparable to 2011.
 
Re: Re:

Durden93 said:
SeriousSam said:
So what's the time adjusted for the trackstanding towards the end?
41:15 total. Quintana finished 47 seconds back after being 1:00 down with 3km to go. I think if they rode hard that gap would’ve gone out to 1:10 or before the climb flattened out. I think Quintana probably would’ve lost 1:15 if everyone went full gas. So many 30 seconds lost? I think the times are comparable to 2011.
2011 times were about 42+minutes for the GC group (Evans, Schlecks etc). Fastest was about 41:30.
 
Apr 20, 2016
457
7
3,295
Interesting data. By comparison what were some of the numbers like back in the Armstrong era pre-ABP? How about in Big Mig's heyday?

Is this a good indication that things are clean(er) now? Has cycling finally turned the corner?
 
I got close to what Alex has just using the rough VAM formula.

About the time lost doing to slowing down, jockeying for position: I agree with the other poster who suggests 30" max. I went back and looked at the "as it happened" report. Beginning with 10 km to go, these are the times that various km were raced (sometimes determined from a longer or shorter specified distance):

3:50
4:04
3:24
2:58
4:54
3:14
2:24
3:06
3:10
3:10
1:58

There are two outlier values. The 1:58 for the final km is presumably because the riders were sprinting at that time. The 4:54 time, going from 5 to 4 km left, corresponded to the steepest part of the stage. All the other values are fairly consistent, and don’t suggest any significant slowing down. In particular, over the last four km, the slowest time for a km was a little over three minutes, and the time from 4 km to 1 km was 8:44. Of course, there could be 20-30 seconds hidden in there somewhere, but not a lot more.

Regarding comparisons to the past. Even assuming 30" from slowing down, and a time of 40:45, this is much slower than the heyday of the 90s and early oughts. But not that many times since 2006 have been faster. They include two by Quintana, who was well off his 2013 and 2015 times yesterday, two by Valverde, also a little slower than before, and two by Froome, who was close to his 2013 and 2015 times, about the same if it was effectively 40:45. The view of many that high level blood doping has been curtailed seems supported, and the W/kg estimate is certainly plausible given known values of parameters like V02max and efficiency. That said, I don't think times like these are evidence that no one is evading the passport by raising his HT a few points. These times would be have been very unusual prior to the 90s (there may have been a few similar times in the late 80s, can't remember now), though how much that is due to different tactics, and better equipment, training and roads, who knows.
 
Merckx index said:
I got close to what Alex has just using the rough VAM formula.
I didn't even bother putting the time/speed into my version of the Martin et al model, I just used an old chart of mine showing W/kg vs climb time:



From this blog post of mine from 2010:
https://wattmatters.blog/home/2010/07/ascent-rates-and-power-to-body-mass.html

Merckx index said:
The 1:58 for the final km is presumably because the riders were sprinting at that time.
The final km is pretty flat, even a section of negative gradient.
https://veloviewer.com/segment/4286076/Alpe+d'Huez+-+Tour+de+France
 
Alex Simmons/RST said:
The final km is pretty flat, even a section of negative gradient.
https://veloviewer.com/segment/4286076/Alpe+d'Huez+-+Tour+de+France
Yes, I wondered about that. Looking at the profile at CN, I now see that the gradient drops off quite a bit at the end, a little more than 5% over the final 3 km. Your link does indicate a flat stretch at the very end, but it’s not clear to me exactly how long it is, and the CN profile doesn’t show this at all. Also, from the “as it happened” record, the final km was done in 1:58. If it had been flat, the leaders would have been considerably faster than that—unless, of course, they were slowing down intentionally. If they were, and it was flat, as much as 40-45 seconds could have been lost.

Going with CN, here are some numbers:

1) From the “as it happened” record, 6:41 for the last 2.5 km.
2) From the CN profile, an average gradient of 5.35% over the final 2.8 km, which I assume is the same for the final 2.5 km.
3) From the profile and “as it happened”, plus the VAM formula, the leaders were averaging about 5.9 W/kg prior to the last 2.5 km.
4) Based on 5.9 W/kg and 5.35%, the riders should have been averaging about 1500 VAM over the last 2.5 km.
5) Based on a rise of about 135 meters over the last 2.5 km, and the VAM of 1500, the riders should have done this stretch in about 5:22

This is about 1:20 slower than what they actually did according to the record. They supposedly did wait for Nibali during this time, but it’s not clear how long. They may have slowed down again near the end, but I would have thought Quintana would have gained back more time if they were this slow.
 
Jan 15, 2013
863
0
0
Merckx index said:
The 4:54 time, going from 5 to 4 km left, corresponded to the steepest part of the stage.
Anyone who has climbed it will confirm that the steepest part is at the start.
 
vedrafjord said:
Anyone who has climbed it will confirm that the steepest part is at the start.
You should inform CN that their profile is wrong. And whoever surveyed it apparently could save a lot of money just by riding up it.

Everyone really slow on the PdN, roughly 4.5 W/kg if the speeds shown in the video are correct.
 
Merckx index said:
vedrafjord said:
Anyone who has climbed it will confirm that the steepest part is at the start.
You should inform CN that their profile is wrong. And whoever surveyed it apparently could save a lot of money just by riding up it.

Everyone really slow on the PdN, roughly 4.5 W/kg if the speeds shown in the video are correct.
Someone I coach rode up ADH the other day - as part of a Haute Route event.

I did a quick grab of their elevation data and while it may not be perfect data you can see the key attributes of the steeper initial two kilometres and the flatter section near the top.

 
I get 5.9 W/kg for Kangert up the first climb. He shouldn't have much left for the rest of the race. Same with the chasers, who weren't far behind. MJ group was about 5.40, which isn't very restful, either.

Averaging 5.9 W/kg on the final climb would be about 50 minutes.

Now I see that Quintana did the final climb in about 50 minutes.
 
Merckx index said:
I get 5.9 W/kg for Kangert up the first climb. He shouldn't have much left for the rest of the race. Same with the chasers, who weren't far behind. MJ group was about 5.40, which isn't very restful, either.

Averaging 5.9 W/kg on the final climb would be about 50 minutes.

Now I see that Quintana did the final climb in about 50 minutes.
#TDF2018 Incredible performances. Power data based on measured numbers in Strava (Ten Dam, Gesink). PC = Perfect Cyclist: FTP = 6,4w/kg and Riegel's power curve



Source: https://twitter.com/Xav3r1us/status/1022396251826991104
 
Mar 18, 2009
2,121
0
0
Lequack said:
Power data based on measured numbers in Strava (Ten Dam, Gesink). PC = Perfect Cyclist: FTP = 6,4w/kg and Riegel's power curve



Source: https://twitter.com/Xav3r1us/status/1022396251826991104
:confused:

I don't understand why there is a difference between the "Perfect Cyclist's" assumed FTP of 6.4 W/kg and their estimated (using Reigel's formula) power of 6.15 W/kg for 47:15.

If somebody's FTP is indeed 6.4 W/kg, then at at least when fresh (as apparently assumed here) they would be able to sustain very close to that for that duration.

IOW, I don't that the original author really understands the physiology here (although this really only impacts the first row/last column of the table).
 
If the assumption is that FTP is power over exactly 45 minutes, power over 47.25 minutes would fit the Riegel formula with an exponent of 1.25, which seems way too high. If one uses an exponent of 1.10—still higher than the original formula, but apparently in the range of what others have used—one gets almost exactly 47 minutes.
 
Mar 18, 2009
2,121
0
0
Re:

Merckx index said:
If the assumption is that FTP is power over exactly 45 minutes, power over 47.25 minutes would fit the Riegel formula with an exponent of 1.25, which seems way too high. If one uses an exponent of 1.10—still higher than the original formula, but apparently in the range of what others have used—one gets almost exactly 47 minutes.
IOW, the numbers/assumptions are whack.

(Note for others: based on analyzing data from runners,zctt Riegel came up with an
exponent of -0.07, or 1.07 as expressed above.)
 
Thread starter Similar threads Forum Replies Date
masking_agent The Clinic 0

ASK THE COMMUNITY

TRENDING THREADS

Latest posts