Chris Froome (Sky), prior to his pre-acceleration that distanced Nairo Quintana (Movistar). Richie Porte of BMC was able to stay with the Briton, however, not conceding any time in the GC.

By the numbers: How hard was the Tour de France’s first mountain-top finish?

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The first mountaintop finish of this year’s Tour de France came early — on just the fifth day of the race. The 160km stage concluded with a 6km climb up La Planche de Belles Filles on a day that saw Fabio Aru of Astana solo to victory 16 seconds ahead of Dan Martin, and 20 seconds ahead of Chris Froome.

In the following article, former pro and Dig Deep Coaching co-founder Stephen Gallagher analyses the power data of riders at this year’s Tour de France to see what was involved in posting a good result in the race’s first uphill finish.

This article refers to the power outputs and power-to-weight ratios of the pros. To put these into context and see where the pros fit in relation to everyday riders, check out this post.

Stage 5 was billed as the first showdown for the GC contenders of the 2017 Tour de France and it did not disappoint. A strong, eight-man group went on the attack early with the likes of Philippe Gilbert (QuickStep Floors) and Pierre-Luc Périchon (Fortuneo-Oscaro) along for the ride. The BMC-led peloton did not give them much freedom which meant a very fast stage and a full-gas ride for everyone during this ‘short’ 160km stage.

The break was inevitably caught on the lower slopes of the hilltop finish to La Planche de Belles Filles. This 6km climb, which rises at an average of 8.5% gradient, proved too difficult for many GC contenders with Nairo Quintana (Movistar) and Jakob Fuglsang (Astana) among those to lose time in the battle for Yellow.

Fabio Aru (Astana) took flight in the closing two kilometres and went on to win the stage with a 16-second gap to the fast-approaching Irishman Dan Martin (QuickStep Floors).

Fast start and BMC chasing

The start of the race was fast with an average speed of nearly 46km/h in the first hour. This was due to the fast pace set by BMC in order to limit the lead of the break. The relatively easy terrain allowed riders with ambitions later in the stage to keep their powder dry.

The numbers of the first hour:

Pierre-Luc Périchon (Fortuneo-Oscaro) in the breakaway:

Details Time Power Power-to-weight Speed
Attack at 1km 4:47 405W 5.86 W/kg 55.7km/h
First hour NA 293W 425 W/kg 48.3km/h
First 100km 2h11m05 279W (302W normalised), 4.38 W/kg NA

Jay McCarthy in the peloton:

First hour 180W (220W normalised) 3.49 W/kg

Lilian Calmejane in the peloton:

First 100km 205W (261W normalised) 3.78 W/kg

A large discrepancy! Even with the fast pace in the bunch, the shielded riders were still able to ride at a relatively moderate pace and avoid too many big spikes in power, all of which would be needed later in the race. In contrast, the attackers had to invest huge amounts of energy, all without ever gaining a gap that would allow them to contest of the stage victory.

Into the Hills

As the riders approached the first KOM of the day, the 2.3km-long Côte d’Esmoulières (average 8%), the gap to the break had been narrowed down to about two minutes. The efforts on the climb were the hardest up to that point.

Rider Location Time Power Power-to-weight Speed
Pierre-Luc Périchon Breakaway 7:06 395W 5.72 W/kg 19.5km/h
Emanuel Buchmann Peloton 7:41 332W 5.35 W/kg 18.1km/h
Laurens ten Dam Peloton 7:40 358W 5.34 W/kg 18.2km/h

The strong breakaway showed that they had some energy left as their fight for the mountain points saw them increase their advantage by 25s instead of losing more time. What made this part of the race that much more ‘painful’ was the lack of a descent after the climb. Once over the top, the riders were greeted by an 11km gradual drag which took the chasing peloton around 17 minutes to cover.

Ten Dam averaged 255W (3.81 W/kg) — normalised 290W and 4.33 W/kg — on this hard section of road. This would have been a very uncomfortable 17 minutes as they had just come off a hard category 3 climb and straight onto a long drag without any respite. And all with the peloton in full throttle as they brought the break down to around 90 seconds by the end of this section.

The descent and downhill into the valley was a fast one. Up-and-coming French rider Elie Gesbert (Fortuneo – Oscaro) hit a max speed of over 90km/h as he descended in the peloton before beginning the approach to the final climb. This long downhill saw the bunch average 56km/h for almost 19km. Gesbert averaged a nice 138W (2.19 W/kg) during this 20-minute effort which would have been a nice reprieve. Gesbert’s teammate Périchon averaged 222W (3.22 W/kg) on the same stretch of road, the break losing about 50 seconds to the chasing field.


The run into the final climb of La Planche des Belles Filles was not an easy one. The riders had to tackle another long drag lasting over 10km and averaging 3% gradient with some sections hitting over 6.5%. While not a categorised climb this road did a lot of damage, with many riders heading backwards out of the peloton and the break being brought back to within a minute.

On this long hill, KOM classification leader Nathan Brown (Cannondale–Drapac) rode at an average power of 334W (5.14 W/kg) for 15:30. Riding in the service of teammate Rigoberto Uran, who went on to finish a fantastic seventh, Brown was using up his energy to keep “Rigo” in a good position. The effort was raised as the hill progressed, with Brown riding the last 1.3km of this non-categorised climb at 409W (6.3 W/kg) for 2:32. This would have been a real sting in the tail before the riders even started the final climb of the day.

Fireworks at La Planche de Belles Filles

At 5.8km in length, the climb of La Planche de Belles Filles is not long, but with an unforgiving 8.3% average gradient and maxing out at over 20% at the top, it would be the first real test for the overall contenders.

The breakaway was all but caught in the opening kilometres of the climb as team Sky piled on the pressure to thin the peloton down to a select few. One of the riders who was able to hold on to the pace was huge French talent Lilian Calmejane (Direct Energie). Calmejane made a blistering attack with 4.5km to go, pushing out 600W (8.7 W/kg) for 20 seconds, hitting a max of 786w, 11.4w/kg.

The stats of Calmejane’s full attack: 451W (6.54 W/kg) for 1:15, with a heartrate of 189 bpm.

Despite going to the absolute limit, Calmejane was swallowed up by the GC group after only 80 seconds at the front. This attack was enough to get a small gap and cause a bit of tension in the lead group. But the effort was not sustained long enough for the Frenchman to stay out front.

Calmejane was caught and went on to finish the stage in 36th position, 2:24 down on eventual winner Fabio Aru. It was also in this period that Calmejane hit his peak three-minute power for the day, riding at 434W (6.29 W/kg) for one of the steep sections of the climb. Lilian did the full climb in 18:36 averaging 381W (5.52 W/kg).

Another young and promising rider we’ll be seeing more of during the Tour de France is Emanuel Buchmann (Bora-Hansgrohe), who rode to a solid 22nd place on stage 5, losing only 1:17. On the climb Buchmann rode a very well-paced effort, keeping a consistent power throughout the climb.

Buchmann was still going full-gas in the last 300m as he hit the 20% gradient, producing 434W (7 W/kg) for the last 1:10 of the stage.

Buchmann’s peak 10-minute power was 375W (6.05 W/kg).

La Planche des Belles Filles ascent:

Rider Climb time Power Power-to-weight Speed
Emanuel Buchmann 17:27 361W 5.82 W/kg 19.9km/h
Laurens ten Dam 17:47 380W 5.67 W/kg 19.6km/h
Fabio Aru 16:11 415W* 6.38 W/kg* 21.5km/h

* Estimated

Riders who were to finish in the top 10, such as Rigoberto Uran, needed to average at least 6 W/kg for the climb. And riders who finished 40-50 seconds behind the top 10, such as Buchmann, hit power-to-weight ratios of 5.8 W/kg.

The real spectacle at the front started with about 2.5km to go as Fabio Aru (Astana) accelerated away from the thinned-out group of favourites. By taking into account Aru’s height and weight, his time for the whole climb, the length and gradient of the climb, and the conditions during the stage, it is possible to estimate the power the Italian champion produced on his way to a stage win.

It what was a fantastic finish on the first mountain stage of the Tour de France and the performances have given us an indication of the main players of this year’s race. With bigger days of climbing still to come we’re sure to see fireworks from those who need to regain time, and also from the main favourites as they vie for control of this year’s Tour.

The graphics in this post appear courtesy of VeloViewer and Philipp Diegner.


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