Bochèt de Casèt

Overview

Bochèt de Casèt is an hors catégorie monster, the kind of ascent that measures your patience as much as your legs. Over 25.5 km it drags you from a valley floor at 115 m all the way to a summit at 1645 m — a net gain of 1530 m at an average gradient of 5.99%. That average hides its teeth: the steepest ramp bites at 16.76%. The recorded total ascent is 1446 m, a touch under the net figure, which tells you the road mostly points relentlessly upward with only fleeting relief. This is a full HC effort, and treating it like anything less is a mistake you will pay for near the top.

How the Gradient Unfolds

At 25.5 km, this climb is long enough that the 5.99% average is a poor description of any single kilometre. Expect the road to breathe — shallower stretches where you can settle into a rhythm, punctuated by sharper walls that spike toward the 16.76% maximum. Because the net gain of 1530 m sits above the 1446 m total ascent, you are climbing almost continuously with barely any descent to recover on. The smart approach is to read the climb as a series of efforts stacked back to back, absorbing the steep pitches without burning matches you will need for the final third, where fatigue and altitude conspire against you.

Pacing Notes

On a climb this long, pacing discipline is everything. Anchor your effort to your FTP and hold a sustainable percentage of it from the base — going into the red early on a 25.5 km ascent means a slow, grinding unravelling long before 1645 m. If you don't have a reliable threshold number, run the numbers through the FTP estimator before you ride so your target power is grounded in reality, not optimism. On the 16.76% ramps, let your power surge briefly rather than forcing an even output, then ease back to your target average on the flatter sections. The goal is to arrive at the summit having spent your budget evenly across the full 1530 m of gain.

Gearing

Do not under-gear this climb. With 25.5 km of sustained effort and pitches hitting 16.76%, you want a compact setup and a wide-range cassette to keep your cadence alive when the road stands up. A 34×32 is the sensible minimum for strong climbers, but most riders will be far happier on this HC beast with a 34×34, which gives you a genuine bailout gear for the steepest walls late in the climb when your legs are already deep into the 1530 m of accumulated gain. The extra range costs you nothing on the shallower sections and saves you on the walls.

Summary

Bochèt de Casèt is a proper HC test: long, steep in the wrong places, and unforgiving of a bad pacing plan. Respect the distance, gear conservatively, and ration your effort across all 25.5 km.

Length: 25.5 km
Average gradient: 5.99%
Max gradient: 16.76%
Start: 115 m
Summit: 1645 m
Net gain: 1530 m
Total ascent: 1446 m
Category: HC