Alto de la Carbonera

Overview

Alto de la Carbonera is a category 2 climb that runs 8.8 km from a base at 426 m to a summit of 869 m. That works out to 443 m of net elevation gain, with 422 m of total ascent logged along the way — a signal that the road climbs steadily without meaningful descents to interrupt the effort. The average gradient sits at 5.01%, firmly in the range where a strong rider can hold rhythm but where the length keeps the effort honest. The 10.18% maximum tells you the climb is not perfectly uniform: there is at least one pitch here with real bite.

How the Gradient Unfolds

The headline number is the 5.01% average, but averages hide the story. Spread 443 m of net gain across 8.8 km and you get a climb that spends most of its time in the comfortable-but-relentless 4-to-6% band, punctuated by the steeper ramp that peaks at 10.18%. Because total ascent (422 m) is close to net gain (443 m), you can plan for an almost monotone upward grade — expect very little coasting. The practical takeaway: treat the mellow opening as the true gradient, and hold something in reserve for the double-digit section, because a 10.18% pitch on tired legs late in an 8.8 km effort costs far more than the same pitch fresh.

Pacing Notes

The smart way to ride a climb of this length is by feel and by numbers. Anchor your effort to your FTP: a category 2 climb of 8.8 km will typically take a well-trained rider somewhere in the tempo-to-threshold zone, so aim to sit just below threshold on the 5.01% sections and let your power drift up only when the road kicks toward 10.18%. If you do not know your threshold, run your recent data through the FTP estimator before you plan the ascent. The classic mistake is overcooking the gentle lower slopes and blowing up on the steep ramp — with 443 m still to gain, discipline early pays dividends late.

Gearing

For a climb averaging 5.01% and spiking to 10.18%, gearing choice is about protecting your cadence on that steep pitch. A compact 34-tooth chainring is the sensible front. Pair it with a 34×32 if you are a confident climber who wants to stay seated and spinning through the 10.18% section; step up to a 34×34 if you prefer margin, ride at a lighter build, or expect to arrive at the steep ramp already fatigued. Either way, the goal is to keep the pedals turning on the maximum gradient rather than grinding the 8.8 km out in a gear that is too big.

Summary

Alto de la Carbonera rewards patient, measured riders: a category 2 climb that gains 443 m over 8.8 km at a steady 5.01%, with a single sharp 10.18% pitch to respect. Pace it by feel and threshold, gear it to spin, and the summit at 869 m arrives sooner than the numbers suggest.

Length: 8.8 km
Average gradient: 5.01%
Max gradient: 10.18%
Start: 426 m
Summit: 869 m
Net gain: 443 m
Total ascent: 422 m
Category: 2