18 July 2015

Steve Cummings Sprints Us Under 1% Again!

I am always nervous watching the Tour de France.  My students and I stick our necks out the day before each stage is run when I post our winning-time predictions.  Science drives my interest, but posting predictions on my blog jacks the fun level up considerably.  Today's stage had me pacing in my office!

The French summer weather was once again hot today (33 C or 91 F), and there were no shortages of breathtaking scenery.  Just before the halfway point in the stage, cyclists passed under the Millau Viaduct.  I had to grab a screen capture of that (click on the image for a larger view).
I felt a bit of vertigo as the helicopter cameras provided images from so many views of the bridge.  What a structure and what a feat of modern engineering!  As if that wasn't amazing enough, the stage took riders through the Gorges du Tarn.  I grabbed the image below with about 73 km (45 mi) left in the stage (click on the image for a larger view).
My family will have to visit that place when we are next in France!

All the wonderful scenery was a pleasant distraction because I thought we were going to be too slow on this stage.  The pace on the very first climb was torrid.  After about half the distance was covered, the average speed was around 45 kph (28 mph).  Team Sky then really pushed the peloton on the first category-2 climb.  That is one powerful team that Chris Froome has backing him!  But in the end, the final climb did what we thought it would do; it slowed cyclists enough that we were actually a wee bit fast.  England's Steve Cummings out-sprinted French cyclists Thibaut Pinot and Romain Bardet to win the stage (click on the image for a larger view).
Below is a comparison between reality and our prediction.
  • Stage 14:  4h 23' 43" (actual), 4h 21' 59" (prediction), 01' 44" fast (-0.66% error).
When I saw the final hill do what we thought it would do, I knew we had a shot at keeping our streak alive.  We now have eight consecutive stages with an error of 1.85% or less, and on five of those eight, we were under 1%.  Below is the winner's average speed.
  • Stage 14:  11.28 m/s (40.61 kph or 25.25 mph)
Chris Froome really pushed himself on the final climb and widened his overall lead.  Nairo Quintana of Colombia managed to jump over Tejay van Garderen of the US for second overall.

Tomorrow's 183-km (114-mi) Stage 15 is more accurately described as "hilly," rather than medium-mountain.  It begins in the commune of Mende, which is where today's stage finished.  Cyclists will contend with a category-3 climb at the start, a couple of category-4 climbs about a third of the way into the stage, and a category-2 climb about two-thirds into the stage.  The stage is flat into the commune of Valence.  Below is our prediction.
  • Stage 15:  4h 12' 01" (prediction)
If they don't crack on the early climbs, sprinters should compete for this stage!

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