There are a number of options to cycle to the Passo del Mortirolo
but the variant described here, which begins in Mazzo di Valtellina,
made this pass famous.
The road was paved only in 1990, especially for the Giro d'Italia,
and from then until 2016 it was climbed
ten times during the Giro.
The Mortirolo owes its fame to its extraordinary steepness.
In the five-kilometer long section,
which begins after three and a half kilometers of cycling,
the average gradient is 13.1%.
This section also includes the steepest kilometer of the whole ascent (15.0%).
In addition, the slope varies again and again
on scales smaller than 500 meters.
Thus, there are sections that are even steeper
than the gradient of the intervals of the profile below.
The advantage of this variation is that
one can recover somewhat in parts that are less steep
but who really succeeds to recover when the slope still measures ten percent?
Obviously an extremely light gear is needed.
Fortunately, the last four kilometers,
which begin more or less at the monument to Marco Pantani in turn 11,
are, with an average slope of 9.8%, relatively easy,
that is, they are as steep as a normal hard climb.
The destination is located at the Passo della Foppa (1852 m),
also known as Mortirolo,
the real Passo del Mortirolo (1896 meters) is located at a different place,
namely if you turn right at the fork behind the Passo della Foppa
and then continue for about one kilometer.
The whole road from Mazzo to the pass
is in a pretty bad condition
and it is so narrow that oncoming cars can hardly move past each other.
Fortunately, there is little traffic in this area that has hardly
been discovered by tourism.