Mt. Aso Hill Climb Course Guide: Riding the Aso Panorama Line in Kumamoto, Japan

The course at a glance

The Mt. Aso Hill Climb is a road cycling race up the southern slope of Mt. Aso in Minamiaso, Kumamoto, Japan. The course follows the Aso Panorama Line (阿蘇パノラマライン), a scenic road that winds from the caldera floor up toward the volcano. I live in Kumamoto and have raced it several times, most recently in September 2026, when I finished in 40:56 for 36th of 92 in the Masters 40 category.

The start. About 11 km of climbing lies ahead. (Photo: Piufoto)

This guide covers what I wish I had known before my first attempt: where the course bites, how to pace it, and how race day works.

Item	Value
Distance	About 11.4 km (Strava segment)
Elevation gain	About 600 m
Average gradient	About 5.3%
Steepest parts	Around 7–8% for long stretches, almost nothing above 10%
Typical finish time	About 40 minutes for a mid-pack masters rider

There are no brutal walls. The challenge is holding a steady effort for 40 minutes on a climb that tempts you to start too fast.

The climb, section by section

1. The start (0–3 km). The first 500 m is nearly flat, then the road climbs at a gentle 3–4%. Everyone goes out hard here. My own data shows the same pattern every year: my highest power was always in the first climbing section, carried over from the adrenaline of the flat start. Hold back.
2. The switchbacks (3–8.5 km). This is the heart of the race: a long stretch at 6–7% with a series of tight corners. Take the outside line, where the gradient is gentler. This is where the race is won or lost.
3. The view. Once you leave the forest, the landscape opens up into the wide grasslands and volcanic peaks of Aso. It hurts, but lift your head for a moment. On a clear day it is spectacular.
4. The straight before the tunnel. A long, straight, steady grade where you can see far ahead, which makes it mentally tough. Look a few metres in front of your wheel and just keep turning the pedals.
5. The tunnel. Almost flat inside. Do not stop pedalling completely: I once cramped here after easing off too much. Keep spinning lightly, then build up again for the last 2 km.

How to pace it: lessons from three years of power data

Still looking fresh. I should have spent that energy in the switchbacks. (Photo: Piufoto)

Holding back early works. Across three races on the same course, my average power went down each year while my average speed went up.

Year	Average power	Average speed
2023	200.7 W	16.31 km/h
2025	194.7 W	16.83 km/h
2026	193.0 W	17.08 km/h

In 2026 I planned the race with an AI coach (Claude), using my past ride files. The plan was simple: treat the first 3 km as a warm-up, then hold a steady effort through the switchbacks, and empty the tank in the last 2 km.

The first part worked. The second did not: through the 3–8 km switchbacks I rode at 182–195 W against a plan of 202 W, while my heart rate still had room to spare. I finished with legs left over, and that is the most frustrating way to miss a target.

Plan (line) vs actual (dots). Orange marks the switchbacks.

My advice for a first-timer:

• Start 5% below your target power for the first 3 km, even if riders stream past you.
• Commit in the switchbacks. If your power drops below target there and your breathing is still under control, push back up.
• Use 1 km auto-laps and watch lap average power rather than instant power. The corners make second-by-second numbers jump around.
• Ride past the finish line. Aim for a point 30 m beyond it so you do not ease off before the timing mat.

Race day and after the climb

Approaching the finish line. (Photo: Piufoto)

Details change from year to year, so always check the official race information. This is how it worked in 2026.

• Base: Riders gather at Aspecta, an outdoor event venue in Minamiaso, about an hour's drive from Kumamoto city. Registering the day before saves a very early morning.
• Getting to the start: Riders roll out together for about 7 km to the start area near Hakusui. These roads are open to traffic, so keep left. You can leave a gap to the group ahead and use the ride as part of your warm-up.
• Summit bag: You can hand in a bag with warm clothes to be carried to the top, either at Aspecta or at the start area.
• Waves and waiting: Categories start in waves between about 8:30 and 10:30. The wait can be long, so do a few short efforts before your wave, or treat the first 3 km of the climb as your warm-up.
• Weather: The race has been held in both September and November. In September 2026 it was about 21–24°C and sunny; in November 2025 it was below 10°C at the start. Pack for both.

After the finish:

With my teammates at the top after the finish (I am on the right).

• Free race photos are published on Piufoto, searchable by race number.
• Lunch: Kugino Soba Dojo near the course serves handmade buckwheat noodles. A large bowl with tempura is a well-earned reward.
  

  A large plate of soba with tempura, with a view of the pastures.

• Watch the climb: My on-bike video of the 2026 race is on YouTube.

About me

I am a road cyclist based in Kumamoto, riding the roads around Mt. Aso and Mt. Kinbo (also spelled Kinpo) every week. I write about training, races and local routes on this blog, and I am working toward guiding visiting cyclists around Kumamoto.

If you are planning to ride Aso, feel free to reach out on X (@radaha). The full race report with every kilometre of power data is in Japanese here.