Reposted from cervelo.com but without the comments section (which had some great suggestions for other stages)
Stage 11 of this Giro may go down as one of the biggest game-changers ever, but we won’t really know until the Giro is over. Here are the 3 biggest leader’s jersey changes in Grand Tours that I could think of off the top of my head. If you know of others, let me know via the comments section.
This stage from Béziers to Montélimar was won by Jens Voigt (Cervelo note, it was the first victory for the Soloist Carbon, the aero road bike that is the predecessor of the S2). But at the end of the Tour (well, three days after the end), it turned out that the big news of that day was the second place finisher, Oscar Pereiro. He was nowhere near the best climbers in the Alpine stages and was close to 30min behind the yellow jersey before the stage. 230 kilometers later, he was in yellow as the whole peloton had taken the day off and nobody was too concerned about him with the Pyrenees still ahead. But in the most unbelievable performance improvement of the race (even more so than the Landis recovery that got most of the attention that year), Pereiro was a completely different rider in the Pyrenees than he was in the Alps. He hardly lost any time, dropped to second in the final time trial and moved back to first after all the lawsuits and appeals were wrapped up in the Landis doping case.
#2: The favorite goes down – 1951 Tour de France, Stage 16
This stage went from Carcassonne to Montpellier, and was fairly flat. My all-time hero Fausto Coppi was in yellow, and seemed in control. I believe the beginning of the end was caused by the Algerian Zaaf (more famous from the 1950 Tour when he escaped the peloton in intolerable heat, drank a bottle of wine to stay hydrated, fell asleep under a tree to cool down and woke up to keep going and before long saw the peloton coming towards him – he had gone back where he came from!). His jump on the way to Montpellier was followed by by a big group of riders including Coppi’s rival Hugo Koblet, and Coppi missed the break. He organized a chase, got to within a few meters but never closed the gap. Eventually, he bonked and lost the yellow jersey to beautiful Hugo, who had time enough to take his trademark comb from his back pocket and arrange not only his own, but the entire peloton’s hair at the finish before Coppi arrived half an hour later.
#1: The favorite rises up – 1956 Giro d’Italia, Stage 18
This stage probably displayed the worst weather ever in a bike race. Hampsten’s Gavia epic and this year’s Giro’s rain and mud avalanches are – with all due respect – a walk in the park compared to the rain, snow and minus 10 degree temperatures of this stage. Even Angelo Zomegnan would not have allowed a stage like this to be held. In fact, conditions were so slippery that many riders descended the climbs on FOOT. Pink jersey wearer Pasquale Fornara went deaf from his teeth chatter and abandoned, several riders succumbed to hallucinations and the Eagle of Toledo – Frederico Bahamontes – was lost for hours and hours before the organization finally located him. The only rider who seemingly enjoyed the conditions was Luxembourg’s Charly Gaul. He was 24th at the start of the stage, rode most of the stage in short sleeves but after more than 200k through this mess and with the 16km final climb still to go, his director sportif noticed that even Charly was starting to show worse for wear and no longer completely “with it”. So he went ahead and ordered a local establishment to run a hot bath. He put Charly in the bath for 5min, put some dry clothes on him and Charly went on to win the stage and the overall. You can read great accounts of this stage in Paolo Facchinetti’s “l’Apocalisse sul Bondone” and in the best cycling book ever, Tim Krabbé’s “The Rider”.