Passo Xon

Overview

Passo Xon is a 12 km Italian climb that trades brute steepness for endurance. From a valley start at 236 m, the road threads upward to a 673 m summit — a net gain of 437 m over the full length. The average gradient sits at a modest 3.64%, which places this firmly in the "rhythm climb" bracket rather than the wall-and-suffer category. That gentle mean earns it a category 3 rating, two full rungs below the hors catégorie monsters and a step milder than a category 2. It is the kind of ascent you can attack rather than merely survive, provided you respect the fact that the number on the sign averages out a good deal of variation.

How the Gradient Unfolds

The headline figure of 3.64% hides the real texture. With 12 km covered and only 437 m of net height to show for it, long stretches must tilt well below that mean — false flats and shallow drags where speed is cheap. Interestingly, the total ascent of 417 m comes in slightly under the net gain of 437 m, which tells you the road climbs almost relentlessly in one direction with little in the way of descending relief along the way. The counterweight arrives as a maximum pitch of 10.97%, nearly three times the average. Expect one or two ramps that briefly bite into double figures and force a gear change, book-ended by the easy gradients that let your legs recover.

Pacing Notes

Because the climb is long but rarely severe, this is a tempo effort, not a series of anaerobic surges. Anchor your pace to your FTP and aim to hold a steady, sustainable output across all 12 km, spending your matches only on the 10.97% ramp rather than bleeding energy on the shallow sections where drafting and momentum do the work for free. If you are unsure of your threshold, run a quick check with the FTP estimator before you plan a target power. The trap on a climb this gentle is going out too hard on the easy lower slopes and arriving at the steepest pitch already in the red.

Gearing

For most riders a compact chainring paired with a wide-range cassette is more than enough here. A 34×32 will comfortably cover the 3.64% average and give you a manageable cadence through the bulk of the climb. Reach for a 34×34 if you want extra insurance for the 10.97% maximum, or if you are carrying fatigue and prefer to spin the hard ramp rather than grind it. Given the modest overall gain of 437 m, you will not need anything more exotic than that.

Summary

Passo Xon rewards steady, threshold-paced riding: 12 km of mostly gentle gradient with a single sharp ramp to break the rhythm. Keep something in reserve for the 10.97% pitch and the summit at 673 m comes quickly.

Length — 12 km
Average gradient — 3.64%
Max gradient — 10.97%
Start — 236 m
Summit — 673 m
Net gain — 437 m
Total ascent — 417 m
Category — 3