The Colle delle Finestre holds a place of its own in Italian cycling: a climb that switches abruptly from asphalt to an unpaved track for its final eight kilometres, used by the Giro d’Italia on several occasions, including the memorable 2018 stage where Chris Froome built his overall win on its slopes.
A climb in two acts
From Susa, the first ten kilometres climb on asphalt at a steady average, before the road gives way to a dirt-and-gravel track for the final eight kilometres up to the 2,178 m summit. Expect 18.5 km and 1,750 m of climbing in total, averaging 9.2% that barely eases off across the whole route. The hairpins on the unpaved section in particular give a bare, mineral backdrop quite different from the usual Alpine-pass scenery.
Getting the ride right
A wider tyre than a standard road setup makes the unpaved section noticeably more comfortable, without requiring a dedicated gravel bike. The track, packed but occasionally uneven, calls for extra caution on the descent, especially after rain.
When to go
June to September — the unpaved high-altitude section tends to stay rideable later into the season than fully paved passes, thanks to its exposure and lighter maintenance. Avoid days right after rain, when the track turns slick.
Good to know
Susa, a historic town at the entrance to the valley, has a decent choice of accommodation, with convenient access to Sestriere and neighbouring ski resorts to extend the trip in the Cottian Alps.
