Simplonpass

Overview

Simplonpass is a hors catégorie ascent that earns its HC label the hard way: 17.5 km of climbing at an 8.19% average gradient, hauling you from a valley floor at 664 m up to a summit at 2100 m. That is a net elevation gain of 1436 m in a single, unbroken effort. The total ascent of 1361 m sits just below the net figure, which tells you the road climbs almost relentlessly upward — there is very little descending to give the number back. When a climb this long holds an average above 8%, there is nowhere to hide. This is a sustained-power test more than a puncher's playground, and the 26.89% maximum gradient means at least one ramp will try to break your rhythm entirely.

How the Gradient Unfolds

The defining tension of Simplonpass is the gap between its 8.19% average and its 26.89% maximum. An 8% average over 17.5 km is already a full-hour effort for most riders, but the presence of pitches near 27% means the climb is not evenly paved with pain — it stacks steeper sections on top of an already demanding baseline. Expect long stretches that hover around the average, punctuated by ramps that spike far above it. Because the total ascent (1361 m) is slightly less than the net gain (1436 m), the profile trends upward almost the whole way, with only minor relief. Treat every gentler section as a chance to recover heart rate before the next steep wall, not as a reason to accelerate.

Pacing Notes

On a climb like this, discipline beats bravado. The single most useful reference is your FTP — your sustainable threshold power. Over a 17.5 km effort you should aim to sit comfortably below threshold on the average-gradient sections, saving headroom for the 26.89% spikes where power will surge whether you like it or not. A common mistake is going out hard in the first few kilometres and paying for it across the remaining 1436 m of vertical. If you do not know your number, run the numbers through the FTP estimator before you commit to a pacing plan. Ride the ramps steady, breathe the flatter grades, and let the summit at 2100 m come to you rather than chasing it.

Gearing

Do not under-gear this one. With a 17.5 km climb averaging 8.19% and touching 26.89%, most riders will want the lowest ratios they can reasonably fit. A compact 34-tooth chainring paired with a 34×32 cassette gives a solid baseline for the sustained gradient, but on the steepest ramps a 34×32 can feel harsh. If your derailleur allows it, a 34×34 buys you meaningful spin on the near-27% pitches and helps protect your knees over 1436 m of gain. Choose the easier setup if you are in any doubt — spinning slowly beats grinding to a stall on a 26.89% wall.

Summary

Simplonpass is a proper HC climb: long, steep, and unrelenting from 664 m to 2100 m. Respect the average, fear the maximum, gear low, and pace to your threshold.

Length: 17.5 km
Average gradient: 8.19%
Max gradient: 26.89%
Start: 664 m
Summit: 2100 m
Net gain: 1436 m
Total ascent: 1361 m
Category: HC