Colle Margherina

Overview

Colle Margherina is a genuine hors catégorie beast, the kind of climb that earns its HC stamp not through a single brutal wall but through sheer, relentless duration. Over 21.7 km the road claws its way upward at an average of 7.81%, lifting you from a valley floor at 723 m all the way to a summit at 2416 m. That is a net gain of 1693 m — nearly the height of a modest mountain stacked entirely into your legs. With 1663 m of total ascent packed across the profile, there is almost nowhere to hide and precious little coasting. This is an all-day objective: a climb you plan a ride around, not one you stumble onto.

How the Gradient Unfolds

The headline number, 7.81%, is deceptively tidy. Averages smooth over the reality, and here the reality bites in the form of ramps touching 15.11% — roughly double the mean. That gap between average and maximum tells you the climb is not evenly graded; it breathes, stiffening into steep pitches before easing back toward something survivable. Because net gain (1693 m) sits above total ascent (1663 m) in the way these figures are measured, the road is essentially one long upward push with negligible relief, so you rarely recover the altitude you have banked. Expect the hardest kicks to arrive when your reserves are already thin, and treat every eased section as a chance to reset your breathing rather than to accelerate.

Pacing Notes

On a climb this long, discipline beats ambition. Anchor your effort to your FTP and settle in just below it — a 21.7 km ascent leaves no room to burn matches early. If you do not know your threshold, run the numbers through the FTP estimator before you commit, because misjudging pace over 1693 m of gain is punishing. The altitude adds a further tax: with the summit at 2416 m, thinner air will quietly shave watts from the top of your range, so ride the steep 15.11% ramps out of the saddle briefly, then sink back to a rhythm you can hold for the full hour-plus this climb demands.

Gearing

Do not under-gear this one. For most riders a compact 34-tooth chainring paired with a wide cassette is the sensible floor. A 34×32 will get strong climbers up the sustained 7.81% grade, but on the 15.11% ramps late in a 21.7 km effort it can feel cruelly tall. If you have any doubt about your climbing legs or fitness on the day, fit a 34×34 — the extra sprocket buys you a lower cadence gear that keeps your knees and threshold intact deep into the ascent. On an HC climb, spinning survives; grinding does not.

Summary

Colle Margherina is a summit worth respecting and, once conquered, worth boasting about. Pace it patiently, gear it generously, and let the numbers do the talking.

Length: 21.7 km
Average gradient: 7.81%
Max gradient: 15.11%
Start: 723 m
Summit: 2416 m
Net gain: 1693 m
Total ascent: 1663 m
Category: HC