July 20 Stage 17: Gap to Pinerolo (Italy), 178km (110.6 miles)
This first of three stages in the Alps heads into Italy via the Cat. 1 climb to Sestriere, but this is more than 60km from the finish, so the real action won’t take place until the brutal Cat. 2 Colle Pra Martino. On a narrow, very twisting back road, this 6.7km climb averages 6.2 percent, but it has a 12-percent section just before a summit that’s only 7km from the line in Pinerolo. The 3km-long, switchback descent averages a vertiginous 15 percent and that’s where the stage can be won and lost.
THE SCOOP: The Pra Martino climb was used in a Giro d’Italia stage to Pinerolo in 2009 when, of the riders doing this year’s Tour, the best were Ivan Basso, Levi Leipheimer and Damiano Cunego.
OVERALL RATING: ***