Famous climbs · Italy

Passo del Mortirolo (Mazzo di Valtellina): ride it free on your smart trainer

11.3 km from 556 m to 1852 m. See where it gets steep, work out how long it will take you at your watts, then ride it in WattLog with your trainer following the gradient.

Length11.3km
Elevation gain1295m
Average grade11.5%
Max grade (200 m)23.0%

About the climb

The Mortirolo from Mazzo di Valtellina climbs out of the Valtellina in Lombardy, northern Italy. It is short but very steep: 11.3 km from 556 m to 1852 m, 1295 m of climbing at 11.5% on average, the second steepest average on this list after the Zoncolan.

There is no warm-up. The second and third 500 m average 15% and 19%, and the steepest 200 m on our track reaches 23%. After a short spell at 8 to 9%, the hardest sustained block follows: from 2.5 km to 7 km the gradient holds mostly 13 to 15%. The last 4 km are easier: 9 to 10%, dropping to 6 to 8% near the top.

Pacing tip: the calculator gives 1 h 25 min at 3.0 W/kg for a 75 kg rider. On grades like these speed is low and every gear counts; ride the first 7 km at or slightly under your target, because the easier top half is where you can still gain time.

Elevation profile

Elevation profile of Passo del Mortirolo (Mazzo di Valtellina): 556 m to 1852 m over 11.3 km 500 m 1000 m 1500 m 2000 m 0.0–0.5 km: 8.8% 0.5–1.0 km: 15.5% 1.0–1.5 km: 19.3% 1.5–2.0 km: 9.2% 2.0–2.5 km: 7.7% 2.5–3.0 km: 15.4% 3.0–3.5 km: 14.8% 3.5–4.0 km: 13.7% 4.0–4.5 km: 13.8% 4.5–5.0 km: 13.3% 5.0–5.5 km: 10.1% 5.5–6.0 km: 14.7% 6.0–6.5 km: 13.0% 6.5–7.0 km: 10.2% 7.0–7.5 km: 12.2% 7.5–8.0 km: 10.5% 8.0–8.5 km: 9.5% 8.5–9.0 km: 9.6% 9.0–9.5 km: 8.6% 9.5–10.0 km: 9.8% 10.0–10.5 km: 7.2% 10.5–11.0 km: 8.5% 11.0–11.3 km: 6.0% 0 km 1 km 2 km 3 km 4 km 5 km 6 km 7 km 8 km 9 km 10 km 11 km
  • under 4%
  • 4–7%
  • 7–10%
  • 10% and over

Each 500 m of the profile is coloured by its average gradient.

Route

Route of Passo del Mortirolo (Mazzo di Valtellina), north up, from the start (green) to the finish (red) Start Finish

Start   Finish   North is up

How long will it take you?

Enter the power you can hold for the whole climb and what you and your bike weigh. The estimate rides the profile 100 m at a time at steady power, with no wind and a road bike position.

Your numbers
Time —
Average speed — km/h
Power to weight — W/kg
Time at 2.5 / 3.0 / 3.5 / 4.0 W/kg for a 75 kg rider and 8 kg bike
2.5 W/kg188 W1 h 41 min6.7 km/h
3.0 W/kg225 W1 h 25 min8.0 km/h
3.5 W/kg262 W1 h 13 min9.3 km/h
4.0 W/kg300 W1 h 04 min10.6 km/h

Real climbs take longer when you start too hard, stop, or ride into a headwind. Treat the number as the pace to aim for, not a promise.

Ride Passo del Mortirolo (Mazzo di Valtellina) on your trainer In WattLog this climb is a route you can ride for free: your smart trainer's resistance follows the gradient, and the climb panel shows how much is left to the top.

Ride it free in WattLog

More climbs and tools

All famous climbs Power to speed calculator Watts per kg calculator

Route © OpenStreetMap contributors (ODbL) · Elevation: Copernicus DEM GLO-30 © DLR e.V. 2010-2014 and © Airbus Defence and Space GmbH 2014-2018 provided under COPERNICUS by the European Union and ESA