With the second rest day in Pau behind them, the riders of the Tour de France head into the mountains for the final phase of the race. The yellow jersey contenders, just two mountains stages and the final long time trial remain to make their claim to the 2012 Tour victory. Beginning on Wednesday, the Tour heads into the Pyrénées for two difficult mountain stages. A flat stage follows and offers some respite. Then comes the final time trial that will decide the Tour once and for all.
After the first time trial and the journey through the Alps, Bradley Wiggins holds a commanding lead in the general classification. Wiggins leads his teammate Chris Froome by 2:05. Italian Vincenzo Nibali sits third at 2:23, while 2011 Tour champion Cadel Evans is fourth at 3:19. It will take some determined riding to overtake Wiggins. Throughout the Alps, his Sky teammates have kept a tight hold on the race, and despite efforts from Evans and Nibali, the team has created an impregnable barrier around Wiggins. Perhaps these next mountain stages will weaken their hold. In the third week of the Tour, anything can happen.
Wednesday's stage 16 runs from Pau to Bagnères-de-Luchon. It heads south from Pau into the Pyrénées and the riders face four massive mountain passes and a screaming fast descent to the finish.
The stage includes the massive col du Tourmalet, which first appeared in the 1910 Tour de France. The riders called the organizers "assassins" for including the pass, but the Tourmalet has provided the scene for many of the Tour's legendary moments. It was on the descent from the Tourmalet where Eugène Christophe broke his forks during the 1913 Tour. He walked more than ten kilometers with his bike on his shoulders. Then when nearly all hope was lost, he came upon a blacksmith's forge. There he fixed his forks and three hours later, he continued on his journey to Paris.
No one will be fixing his own forks on Wednesday, but they must still make their way up the fearsome Tourmalet just as Christophe and others before and after him have done. Setting out from Pau, the riders face around 40 kilometers of gradual uphill false flats. There's on uncategorized climb along the way, but this is the kind of steady uphill grind that while it isn't immediately noticeable it saps the legs all the same.
The col de l'Aubisque is the first climb of the day, and it runs 16.4 kilometers. The Aubisque carries at hors catégorie rating and the gradients are in the 8-10% range. Typically, the roads in the Pyrénées are narrower and the road surface less smooth than in the Alps. That tends to make the climbing more difficult than they appear on paper. In the 2005 Tour de France, Cadel Evans went on a long bomb of an escape on the col de l'Aubisque, a move that sent him from eleventh to seventh in the overall. He finished that Tour eighth. 
From the Aubisque, it's a long descent to Adast. There are a couple bumps along the way, so it's not all swoopy, descending goodness. The race runs up the valley for around 15 kilometers. Then, it's time for the mighty col du Tourmalet. The Tourmalet is an interminable 19 kilometers of climbing. The gradients are not especially ridiculous. The maximum is 10% and the majority is in the 7-8% range. But the length, that'll leave a mark. The summit of the Tourmalet sits at 2115 meters and the first rider to reach the top receives the Souvenir Jacques Goddet.
This stage follows the pattern typical of this year's Tour — the most difficult climbs come some distance from the finish line. The summit of the Tourmalet is around 70 kilometers from the stage finish in Bagnères-de-Luchon. That complicates the tactics for riders who have hopes of overturning the classification. A bit move on the Tourmalet risks being brought back long before the finish line comes into view. And, there are still two significant climbs on the menu after the Tourmalet.
From the summit of the Tourmalet, it's a fast descent down the eastern slopes of the mountain by way of La Mongie, which has also frequently served as a stage finish. It's a fast descent of 17 kilometers to Saint-Marie-de-Campan. From there, it's straight back to the business of climbing.
The col d'Aspin is 12.4 kilometers in length, and only the final four kilometers are especially difficult. Coming straight after the Tourmalet, there will be nothing especially easy about this climb, but it's not one of the monsters of cycling. The maximum gradient is 8% and for much of the climb it's a "pedalable" 3-4%. (That word, it never sounds as good in English as it does in Italian.) The Aspin summits with 47 kilometers to race. The riders have around 13 kilometers of descending from the summit of the Aspin to Arreau.
Final climb of the day! The final climb of the day is the col de Peyresourde. The Peyresourde, it only looks easy next to the Tourmalet, but it's a solid 9.5 kilometers of climbing. The maximum gradient is 10% and it should be a madhouse of partying fans on the upper slopes. There's a catch, of course. A rider who hopes to use this climb to his advantage must also descend down the other side.
From the summit of the final climb of the day, there remains 16 kilometers of racing. It's nearly all descending. The riders with agile bike handling and clear heads will thrive here. The descent finishes with just 2.5 kilometers to race. Then, it's a flat run-in to the finish in Bagnères-de-Luchon.
Any rider who hopes to wrest the jersey from Bradley Wiggins' tight grasp will have to be crafty indeed. This is not a course where brute strength can win the day. Stellar legs on the climb and brilliant bike handling on the descents — A rider will need both of those things to turn this difficult mountain stage to his advantage.
Time Table! On the fastest time schedule, the riders will begin the col du Tourmalet at 14:13 France time. That's 5:13 west coast/8:13 east coast. They summit the Tourmalet at 14:46 France/5:46 Pacific/8:46 east. The beginning of the col d'Aspin is at 15:15 France/6:15 Pacific/9:15 east. Summit of the Aspin? 15:37 France/6:37 Pacific/9:37 east. Summit of the Peyresourde is at 16:30 France/7:30 Pacific/10:30 east. Fastest finishing time is 16:57 France/7:57 Pacific/10:57 east. Best of luck to my friends on the west coast!