Originally Posted by
Rowan
Oh yes, he definitely did. He had a bigger chainring fitted to the bike for that particular stage, and even though the attack was a spur-of-the-moment thing, it was obvious he had rehearsed the technique in training, and this was stated as so. He left his main opposition, chiefly Quintana, floundering. Nevertheless, as I recall, he was some kilometres an hour faster on that descent that all the other drafting riders.
This isn't the first time a lone cyclist in a Grand Tour has outpaced a group on a descent, whether first up the climb or gapped off the back. It seems fairly common even for the lone descending cyclist to be faster given that they have more of the road to use and can pick better lines through the corners. Perhaps the aero penalty of pedaling while sitting on the top tube isn't that bad due the air speeds being lower near the road and feet not being all that wide to begin with, and perhaps Froome isn't a good enough descender to make those sorts of gains on a chasing group without pumping out some massive watts.
Quintana was left floundering because he took so long to react in my opinion, though Froome can also take a big chunk of credit for a very well planned attack.