A first rocky stairway to heaven can be found on the Strada dell’Assietta - also known as the SP173: it’s 34 kilometers long, and curls almost entirely above 2.000 altimeters. Because of the high altitude, it’s only open from June 1st to October 31st.
The road itself runs along the ridge that separates the Val Chisone and Susa valley and passes several mountain passes between both valleys including Colle dell'Assietta (2.474 m), Colle Blegier (2.381 m), Colle Costa Piana (2.313 m), Colle Bourget ( 2.299 m) and Col Basset (2.424 m) - all of them potential preys for you to devour on the back of your bike.
As a direction of travel, we’d suggest you to start off in the north and make your way towards the south: while the northern ramp does not only surprise you with innumerable bends, it also is a gravel-only road, whereas the south ramp is narrow but completely paved - which might be an easier descent if you aren’t riding on knobbies.
As the road was constructed for military use during the 1800’s, you won’t be surprised to spot a few fortifications along the way. On the south side for instance, the road takes you past a few of them, sadly most of them have a blocked entrance. But rest assured, even from the street you’ll have plenty of insights into the military history and the architecture of past centuries.
By far the most interesting structure is the immense Forte di Fenestrelle complex, which rises from the valley for about three kilometers along the southern slope of the Valle del Chisone, overcoming a difference in altitude of almost 600 meters. A huge complex, well worth a visit. Just take your time…
Once you’ve devoured this section, make sure to turn left onto the Strada del Colle delle Finestre (read SP172), which will first drag you over a narrow but paved road, which afterwards turns into an equally tight, but gravelly road. Delicious stuff. However, be careful if the forecasts predict rain: the surface gets very slippery in wet conditions.
Although not for the faint of heart, both the SP173 as the SP172 are rather doable to ride on a normal streetbike - if you have the proper experience, that is. Just beware: the road is closed for motorbikes on wednesdays and saturdays, so plan your trip ahead. You wouldn’t want to miss out on these ones.
See the road from Colle delle Finestre to Assietta.