Lombardy, Italy · from Mazzo di Valtellina
Passo del Mortirolo
The Mortirolo from Mazzo is widely regarded by professional cyclists as the most punishing climb in Europe. A narrow, relentless road pitches upward through dark forest at an average 10.5%, spiking to 20% with almost no flat sections to break your rhythm.
Summit elevation: 1852 m
Route overview
Passo del Mortirolo · from Mazzo di Valtellina
Schematic road geometry from the routed track, with 27 detected hairpins marked (filled markers are tighter than 15 m radius). Use it to see the shape of the climb, not for navigation.
Measured road detail
Taken from the Passo del Mortirolo track used by the 3D flyover: Mazzo di Valtellina → Passo del Mortirolo · 589 road points
- Measured length
- 11.52 km
- Measured ascent
- 1291 m
- Elevation range
- 562 → 1852 m
- Hairpins detected
- 27
- Tightest hairpin
- 7.6 m radius
- Surface
- Asphalt
The routed track measures mazzo di valtellina → passo del mortirolo, a slightly different start or finish than the from Mazzo di Valtellina profile this page simulates, so its length and ascent are reported separately from the headline figures above.
Tightest hairpins on Passo del Mortirolo
- 5.8 km · 1240 mRight · 10.4 m
- 6.2 km · 1280 mRight · 7.8 m
- 7.5 km · 1450 mLeft · 7.6 m
- 8.5 km · 1564 mRight · 11 m
- 10.1 km · 1728 mLeft · 9.7 m
- 10.8 km · 1799 mLeft · 10.5 m
Landmarks along the way
- San Matteo church
- Marco Pantani monument
Hairpins and elevations are derived from the routed track; road data © OpenStreetMap contributors (ODbL).
How fast would you climb Passo del Mortirolo?
Enter your power and weight. A physics engine calculates your estimated time against the gradient profile.
Predict your
performance.
See how power and weight affect your time on a real climb.
*Demo simulation uses standard road bike physics (CdA 0.32, Crr 0.004).
Passo del Mortirolo and the Tour
First introduced to the Giro d'Italia in 1990, the Mortirolo became mythical on Stage 15 of the 1994 Giro when 24-year-old Marco Pantani launched a solo attack, dropping Miguel Induráin and Evgeni Berzin. A monument to Pantani stands at hairpin 11.
Vincenzo Nibali set the modern public Strava benchmark of 44:52 on the 12.5 km Mazzo ascent in 2019. Jack Burke recorded 43:45 in 2024.
44:52 for the 12.5 km Mazzo ascent (Strava public benchmark). Note: Marco Pantani 1994 attack is featured as the iconic story benchmark.
Riding it yourself
When to go
Open from late May through October. Autumn and late spring offer cool weather; summer afternoons in the tight forest can be humid and hot.
Base & logistics
Mazzo di Valtellina in the Valtellina valley is the starting point. Gearing choice is critical: a 34x32 or 34x34 ratio is strongly recommended even for fit riders.
FAQ
How long is the Passo del Mortirolo climb?
From Mazzo di Valtellina, the climb is about 12.5 km with roughly 1312 m of elevation gain at 10.5% average gradient (based on the simplified profile used by this simulator; published figures vary slightly by source).
How long does it take to cycle up Passo del Mortirolo?
It depends almost entirely on your power-to-weight ratio. Use the simulator on this page: enter your FTP and weight, and a physics model (air resistance, rolling resistance, gravity) estimates your time on the gradient profile.
Can I see Passo del Mortirolo in 3D before riding it?
Yes. The route overview on this page has a 3D flyover that follows the real road: 589 routed points covering Mazzo di Valtellina → Passo del Mortirolo, with terrain, gradient and the road's own bends. It runs in the browser, no account needed.
How many hairpins does Passo del Mortirolo have?
27 hairpin bends are detected on the routed track, the tightest turning inside a 7.6 m radius. They are marked on the 2D sketch and ridden in order in the 3D flyover.
How accurate is the time simulation?
The simulator uses a simplified segment profile and standard road bike assumptions (CdA 0.32, Crr 0.004, 8 kg bike). It does not model wind, drafting, altitude, surface or pacing errors, so treat the result as a realistic estimate, not a guarantee.
How should I train for Passo del Mortirolo?
Sustained climbs reward steady threshold and sweet spot work plus a power-to-weight improvement over weeks, not days. TrainCraft builds structured cycling training plans and adapts them when you miss sessions, using fatigue science (CTL/ATL/TSB).
More famous climbs
Preparing for this climb?
A climb like this is won weeks in advance. TrainCraft builds a structured plan around your FTP and available hours, and adapts it when you miss a workout.
Start Training FreeThe profile is simplified into 4 segments for simulation; real gradients vary metre by metre. Stats shown are derived from this simulated profile and closely match commonly published figures. Time estimates assume standard road bike physics and no wind.
Training for a climb like this?
TrainCraft builds structured training plans and adapts them when life gets in the way — real fatigue science (CTL/ATL/TSB), visual workout builder, Strava & Garmin sync. Free to start.