Alto del Tablazo

Overview

Alto del Tablazo is a long, high-altitude grind that earns its category-1 rating the honest way: through length and sustained pitch rather than a single savage wall. Over 15.4 km the road lifts you from 1525 m to a summit at 2605 m, a net gain of 1080 m at an average gradient of 7%. That average alone tells you this is a climb with no meaningful recovery — you are working from the first pedal stroke to the last. Factoring in the small rises and dips along the way, the total ascent comes to 1097 m, so you gain a touch more than the raw start-to-summit figure suggests.

How the Gradient Unfolds

A 7% average across 15.4 km is the headline, but the 18.24% max gradient is where the character lives. Averages hide their steepest moments, and here the spread between the 7% mean and the 18.24% peak is over 11 percentage points — proof that the road ramps hard in places while easing only slightly elsewhere. Expect the climb to breathe in waves: long stretches sitting near or just above the average, punctuated by short, sharp kicks that force you out of rhythm. Finishing at 2605 m adds a further tax. Thin air near the summit blunts your power, so the closing kilometres feel harder than their gradient would suggest at sea level. Plan for the top third to be the true test.

Pacing Notes

The single biggest mistake on a climb this long is starting too hard. With 1080 m to gain, discipline in the first few kilometres buys you everything in the last few. Anchor your effort to your FTP and aim to settle just below threshold on the sustained sections, saving headroom for the 18.24% spikes where your power will surge whether you like it or not. If you are unsure of your threshold number, run the FTP estimator before you commit to a target. Because the summit sits at 2605 m, expect your sustainable output to drift downward as you climb into thinner air — bank effort early rather than betting on a strong finish.

Gearing

Gear for the steep bits, not the average. A 34×32 is the sensible floor here, and on the 18.24% ramps near the top — where altitude has already shaved your power — you will be grateful for a 34×34. The extra sprocket keeps your cadence alive on the kicks and protects your legs across a full 15.4 km of work. If your setup allows anything easier still, use it; nobody has ever regretted a spare gear on a 1080 m climb. Prioritise spinning over grinding, especially above 2000 m.

Summary

Alto del Tablazo is a test of patience and gearing: 15.4 km at 7%, topping out at 2605 m after 1080 m of net climbing, with pitches to 18.24% and altitude stacking the deck against you. Pace it low, gear it easy, and let the mountain come to you.

Length: 15.4 km
Average gradient: 7%
Max gradient: 18.24%
Start: 1525 m
Summit: 2605 m
Net gain: 1080 m
Total ascent: 1097 m
Category: 1