6:53 pm - Mon, Jul 21, 2014
2 notes

5 W/kg is the New Normal (get over it!)

"Tejay pushed 338 average watts up the final climb for over 50 minutes. His cadence average was 84rpm and he maintained an average speed of 21kph. Racing at 1m85 with 68kg, Tejay averaged 228 watts with an average cadence of 76rpm."
http://www.srm.de/news/road-cycling/tour-de-france-stage-13/

Calculating that out, Tejay averaged 5 W/kg for the climb. This number could be evidence of very human levels of performance in this years Tour de France.

It could also be the nail in the coffin on the pseudoscience debate as the model estimate of 5.7 W/kg is a huge 14% off.

But there is an issue here.

Take a look at the model break down for Tejay:

4.86 W/kg are needed to overcome gravity

0.27 W/kg are needed to overcome rolling resistance

and

0.59 W/kg are needed to overcome wind resistance

Of those components 4.86 W/kg is nearly certain as gravity does not change and it was a long climb so timing and elevation change error will be negligible. Similarly rolling resistance is unlikely to be a major source of error of total error since it is such a small fraction of total resistance.

This of course means that the likely source of the error was from wind resistance due drafting or a tailwind (note that I say or rather than and since the tailwind diminishes the benefit of drafting). Starting off drafting can be eliminated as the source of error since a perfect draft would not assist against gravity or rolling resistance which alone add up to 5.1 W/kg. So therefore it must have been a tailwind. And in fact, there was a tailwind on the day. Measured at 10 m above the ground the average wind was 5 km/h. According to calculations by Fred Portelau this translates roughly to about 2.5 km/h at 2m or cyclist height.

For arguments sake, lets say that the wind was a perfect tail wind for the entire climb (in reality it can’t be) that would drop the the wind resistance from 0.59 W/kg down to 0.45 W/kg. So even allowing for an impossible “smart wind” the estimate would only come down to 5.6 W/kg.

To get down to the SRM site reported 5 W/kg there would need to be a cyclist level “smart wind” in the neighborhood of 30 km/h so that Tejay was literally blown up the mountain and that would certainly be not normal.

The point here is the methods for estimating performance aren’t perfect, but they are certainly good enough to pick up that something is way off here.

12:48 pm
Q: Millar's salary dropped by 300 percent? He was paying the team two year's salary just to ride?
Anonymous

the odd places logic leads if we bother to go

12:46 pm
Q: Are the guys in the 2014 TDF on xenon gas?
Anonymous

I don’t know, guys ?

12:07 pm

Rest Day Rebuttals ?

As I did last year I am inviting counterpoints to the estimates and DpVAM models.

Tearing things down is a healthy part of building them up stronger.

Coherent submissions will be published un-edited.

Blanket GIGO statements are GIGO themselves.

My personal rebuttal will focus on wind.

11:12 pm - Sun, Jul 20, 2014
1 note

2014 Tour de France Stage 13 and 14 brief analysis

Sorry about slacking on this post but I’ve got sidetracked into making animated Power Duration curves… more on that later. 

image

Diving right in to the Power Duration curve going from left to right we now have data points from stages 10, 14, and 13.

If stage 14 (sorry had to fix that) jumps out at you as the out-lier, go ahead and pat yourself on the back. Nibali’s nW/kg came in at 6.2 nW/kg (6.1-6.3) and gets tweaked upward for the plot above for altitude. But, notice that the whole group of top 5 looks fast. Tail gunning Valverde estimates in at 6 and the others at 6.1. Compare that to stage 13 were Nibali came in around 5.9 nW/kg with the rest of the top 5 slotting in from 5.7 - 5.8 nW/kg. Complaints of heat taking its toll may account for some of the difference. But there may also have been a bit of a STRAVA sniping effect on stage 14 where riders hit the bottom of the climb at 50 km with a good amount of drafting going on. It would be interesting to look at the estimates at the splits along the way. Fred Portelau has been working on a model to estimate the wind effect which looks quite good so that will be interesting to take into account as he gets his data out. Overall, the picture that is emerging from the numbers is that Nibali is every bit yellow jersey worthy regardless of the absense of Froome and Contador.

Now listen, if you are enjoying this Tour de France and you want to keep enjoying it just stop here and leave it at that.

.

.

.

.

.

.

Just making sure you actually want to see this…

8:50 pm
26 notes

pushingthebuttons:

Tour de France stage 15- Tallard to Nimes 222km

Out of the Alps.

Breakaway of Jack Bauer, Garmin Sharp, and Martin Elmiger, IAM Cycling, escaped the peloton at the start of the stage. Bauer held off the peloton to the last 50 meters when caught by the sprinters. 

Alexander Kristoff, Katusha, claimed his second stage win after the peloton caught Bauer and Elmiger.

It was a cruel outcome for Bauer. 

shoulda worn a proper aero helmet .

(via kyle-lm)

1:58 pm - Sat, Jul 19, 2014
1 note

Got to wonder what the peleton’s local prevalence of anti-biotic resistance given routine over prescription?

“At follow-up, there was no difference in participants described as being clinically improved between antibiotic and placebo groups (11 studies with 3841 participants, risk ratio (RR) 1.07, 95% confidence interval (CI) 0.99 to 1.15”
11:37 am - Fri, Jul 18, 2014
1 note
yer still suckin wheel there yuh jackass

yer still suckin wheel there yuh jackass

9:10 pm - Thu, Jul 17, 2014
2 notes
yer still suckin wheel there yuh jackass

yer still suckin wheel there yuh jackass

6:35 pm
1 note

Why does cycling make me feel

like a conspiracy theorist ?

Install Headline