Thrumshing La

Thrumshing La cycling climb profile

Thrumshing La is not a climb to ride by instinct. At 31.3 km with an average gradient of 9.37%, it sits in the category of climbs where the main challenge is not one decisive ramp, but the accumulation of sustained climbing load. The numbers point to a long, high-cost effort from the start elevation of 802 m to a summit elevation of 3734 m, with 2932 m of net elevation gain and 3110 m of total ascent.

That difference between net gain and total ascent matters. The climb gains 2932 m overall, but the total ascending adds up to 3110 m, which means the road is not simply a smooth mathematical line to the top. Any small losses or flatter interruptions still have to be paid back. On a climb this long and steep, those moments do not make it easy. They change the rhythm, which can be harder to manage than a steady gradient if you respond to every change with a surge.

How the gradient rides

The headline number is the 9.37% average. Over 31.3 km, that is already severe. It means this climb should be paced as a sustained endurance and threshold management problem, not as a sequence of short efforts.

The max gradient of 32.91% is the warning label. Even if that pitch is brief, it changes the gearing requirement and the pacing logic. A rider who arrives at the steepest sections already overextended will be forced into a survival effort, and once cadence collapses on gradients that steep, the cost rises quickly. The smarter approach is to leave margin early, even if the lower slopes feel manageable.

Because the available profile data does not break the climb into kilometre-by-kilometre sectors, the safest reading is also the most practical one: expect a hard baseline gradient for a very long time, with at least some much steeper ramps inside it. The average tells you the climb is consistently demanding. The maximum tells you there are sections where gearing and composure matter as much as aerobic fitness.

Pacing and gearing notes

Start below the effort you think you can hold. On a climb with this much vertical gain, the penalty for riding the opening phase too hard is severe because there is so much climbing still to come. Use perceived effort, breathing control, and power if you have it. If you pace from /glossary/ftp, this is the kind of climb where discipline matters more than ambition.

Gearing should be chosen for the steepest pitch, not the average. A setup that feels fine at 9.37% may be inadequate when the road reaches 32.91%. Prioritise a low gear that lets you keep turning the pedals under load rather than grinding at low cadence for long stretches.

The practical strategy is simple: protect cadence, avoid repeated accelerations after any easier ground, and keep enough reserve for the steepest ramps. Thrumshing La is an HC climb because the numbers compound. Length, gradient, elevation gain, and maximum pitch all push in the same direction.