About Dragon's Tail
Dragon's Tail is the 137km ultra trail at Dragon's Back Race 2026 (Rhandirmwyn, United Kingdom). The race starts on September 11, 2026. It starts in Rhandirmwyn and finishes in Cardiff Castle.
Race strategy
Hold a steady pace and save energy for every section.
- 486m descent. Go easy, save your quads.
- The finish is runnable. Save your legs to run it all the way.
- Long race. Control your HR and effort. Early mistakes cost the most.
- Ease into the early runnable section, save your quads on the descents until 74.5km, then run your race pace.
- Start · 0.0km–1.7km · Race-day nerves push your heart rate up: don't follow the crowd, find your own rhythm.
- Settle in · 1.7km–36.5km · Plus 1 more climb. Ease in: hold back more than feels necessary. The race is still ahead. Climb by heart rate or breathing, not pace. Running pays off here: run wherever you can.
- Work · 36.5km–69.1km · Descent of 403m averaging 9%, descent of 486m averaging 9%, descent of 292m averaging 17%. Plus 2 more climbs. This is where the race is built: steady, solid effort. Climb by heart rate or breathing, not pace. This descent is hard on the legs: short steps, stay in control, poles if you have them. Running pays off here: run wherever you can.
- Fade · 69.1km–79.9km · Descent of 545m averaging 10%. Plus 1 more climb. Your energy fades, and that's normal: hold a steady effort and stop counting the miles. Climb by heart rate or breathing, not pace. This descent is hard on the legs: short steps, stay in control, poles if you have them. Your heart rate drifts down on its own: don't chase your early-race numbers, go by feel.
- Home · 79.9km–139km · 59.3km of runnable trail. No heroics: settle back into your own effort and hold it to the line. Running pays off here: run wherever you can.
Course
The course climbs 4500m+. With 33m/km of climbing, this is a rolling, mostly runnable course. By gradient, 26% of the distance is uphill, 31% downhill and 43% flat. The longest climb runs 5.5km at an average 8.1% grade (450m of vertical). The longest descent runs 5.6km at an average 8.7% grade (486m of vertical). The steepest climb averages 38.8% over 0.3km. The steepest descent drops at 43.7% over 0.2km. Flat-equivalent effort: 181.5 FlatKM.
Poles
Poles bring little benefit here: only about 11.4km of pole-friendly terrain.
Quad damage
Quad damage risk is moderate (index 49 of 100), with 61% of the load in the first half: 4 descents deserve a plan and a couple of downhill sessions before race day.
- Ease into the early runnable section, save your quads on the descents until 74.5km, then run your race pace.
- #2 · 36.5–40.8 km · 403 m D−, -9.4% · 98.4 km ahead → control
- #1 · 44.0–49.6 km · 486 m D−, -8.7% · 89.6 km ahead → control
- #4 · 55.6–57.3 km · 292 m D−, -17.1% · 81.9 km ahead → control
- #3 · 69.1–74.5 km · 545 m D−, -10.1% · 64.7 km ahead → control
Weather
On race day, start temperatures have historically ranged from 11°C to 17°C, with around 8°C at the highest point; the chance of precipitation is about 55%. Heavy rain of 10.0mm or more falls on about 9% of days around this date.
Results
13 finishers completed the 2026 edition. Men's winner: Will Preene (Great Britain) in 19:53:51. Women's winner: Frances Barradell (Great Britain) in 25:26:18.
This page has the full results and splits, a pacing and nutrition planner, a gradient matrix, an interactive elevation profile and historical weather for Dragon's Tail.
Other distances of Dragon's Back Race 2026Dragon's Back Race (384km)·Dragon's Fire (111km)
Other editions of Dragon's Tail2027
Official websitewww.dragonsbackrace.com