“The 2026 Slateman Ultra Triathlon is now open for entry!
Starting and finishing in Llanberis, this isn’t your ordinary triathlon. Swim the cold waters of Llyn Padarn, bike over mountain passes, and trail run through the rugged quarries of Dinorwig. Make the cut-offs, and you’ll summit Yr Wyddfa (Snowdon) before the final push back to Llanberis.
This is not for beginners.
This is not for the curious.
This is for seasoned triathletes who crave extremes; who want elevation, exposure, and a fight against the elements as much as against the clock.
Entries are now open with instalment plans available. “
I’m hoping folks will support this / spread the word. And hopefully it’ll run again in 2027. Imp pressed that (un-inclement weather permitting) you get to summit* Snowdon, like on the Brutal Xtrmeme Tri’s in Sept.
* That’s on the run btw, not the bike
Here’s an Updated list, with provisional UMUK 2027 note added:
2026 UK Middle-distance / Half & Full UK Ironman Events
All dates are a Sunday unless noted, and are confirmed.
There are some ?likely? dates which are just 2025 events listed on the same weekend, but are still obviously tbc….
Please anyone copy/edit/update as they are announced.
May 9 (Sat)
ROC Wales £262 1.5km SEA SWIM, 49.5km ROAD BIKE, 12km Snowdon MOUNTAIN RUN, 49.5km ROAD BIKE, 1km TRAIL RUN
May 16 (Sat)
ATW Big East middle-ish with 1.5k sw1m, noon tidal start!
early Sept 2027 to note for following year, tba/tbc, 3 day stages
UMUK (UltraMan UK), usually at Bala, N.Wales/Snowdonia. Day 1 usually a 10 km sw1m, followed by a 70-90 ish mile bike? Day 2 rest of the bike to make it a total 261 mile ish distance. Day 3 Double marathon 52 miles. The sooner you finish each day, the more neutralised/sleep time you get, like a 3-Day stage race.
Sep 5 (Sat)
ROC England 1.5km LAKE SWIM, 46.5km ROAD BIKE, 18km Scafell MOUNTAIN RUN, 45.5km ROAD BIKE, 1km TRAIL RUN
Sundowner Half, Allerthorpe nr York ?likely date tbc? www.uprevail.events/calendars/sport-events
Sep 19 (Sat)
Brutal DOUBLE, TRIPLE & SINGLE FULL extreme iron + half
Sep 20
IM Weymouth 70.3
Henley Half ‘The One on the River’ - ?likely date tbc?
Sep 27
Sandman Half
Castles Hever Gauntlet half
Oct 3 (Sat)
ROC Scotland Ben Nevis ‘run’ yomp, Offroad bike - hardtail maybe gravel bike if lucky
.
SOME RACES THAT ARE NO LONGER RUN: If your looking for something missing?…
UK Ultimate IM & Half - Ellesmere Shropshire - Ended 2025 (but is now T150:T100:T50 style)
Eastbourne ‘Tribourne’ full IM - Ended 2025. Just a half now, on closed roads! see July 12th above.
MidnightMan IM - Dartford - Ended 2024. John Setford is still daft enough to put shorter Olympic & Sprint etc events on tho. https://www.bridgetriathlon.co.uk/
That’s on the run btw, not the bike 
