Slateman Triathlon 2027
The original Welsh adventure triathlon. A cold swim in Llyn Padarn under Snowdon, a mountain bike leg on closed roads, and a run out onto the slate trails.
43 weeks to race day: base season
Plenty of runway. This far out, the win is a boring, consistent base rhythm: aerobic volume, strength, technique. The structured block starts closer in; what you do now decides how high it can climb.
Building for this one? Ironman training plan covers the sessions, the weekly shape and how the block is paced. The R.A.C.E. Framework explains why it is built that way.
Build my complete road.
Commit to the date and the work gets a shape: your countdown starts, the emails arrive in step with your build, and the app anchors a recovery-led block so the final week lands exactly on race day.
One confirmation email, then the road begins. Registering for the race itself stays with the organiser.
“A proper mountain triathlon and one of the best days out in British racing. The lake is genuinely cold in June, so do your open water prep in cold water, not a heated pool.”
The race
The course
No course maps for this race. The organiser publishes no downloadable route for any leg of this race, so there is nothing to draw a course map from. Everything below comes from the official course page, checked on the date at the foot of this section.
Cold glacial water in Llyn Padarn under the Snowdonia slate quarries. Distances given are for the Legend; the Sprint swims 750m, the Standard 1,500m and the Ultra 2.4 miles.
Not 90km. The Legend bike is 92.6km through the Snowdonia passes; the Sprint is 20.2km, the Standard 49.9km and the Ultra a full 180km.
The Legend run is 23.1km, a full two kilometres beyond a half marathon, and it climbs. The Ultra run is longer still and comes in two versions: 44.5km to the Chwarel finish or 49.9km to the Mynydd finish.
Not yet confirmed for this edition: lap counts, elevation gain, cut-off times, water temperature, transition locations. We publish these only once they are on the official course page, so check there before you pace off anything here.
Course details verified against the official Slateman Triathlon course page on 14 August 2026. Courses change; the official page is always the last word.
Questions, answered
When is Slateman Triathlon 2027?
What distances can I race at Slateman Triathlon?
How hard is the course?
What is the swim like?
How long do I need to train for it?
How do I enter?
Read before you race
IRONMAN Copenhagen Swim: Conditions, Sighting and Preparation
IRONMAN Copenhagen Weather, Nutrition and Clothing Strategy
IRONMAN Copenhagen Training Timeline: From Base to Race Week
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Photograph of Llanberis, Snowdonia, Wales: Klr45pmp, CC0, via Wikimedia Commons. Not official race photography.
This listing is for information only. Unbroken is not affiliated with, endorsed by, or sponsored by Slateman Triathlon or its organiser. Details are based on publicly available information; names are used descriptively to identify the event. For accurate, up-to-date information and to enter, always use the official event website.