Race day for this edition — 5 July 2026 — has passed. The guide stays up for reference.
Upcoming race guides →IRONMAN Switzerland Thun is a single-transition Ironman on the shore of Lake Thun — you rack at one transition at Stadion Lachen, with colour-coded bags for the bike and the run, a white street bag, and optional orange and black personal-needs bags for out on course. The swim is in the lake, the bike climbs into the Bernese Alps, and here's exactly what goes in each.
Swim, bike and run all turn through one transition at Stadion Lachen — you come back to the same rack between disciplines. The two-loop bike heads out into the Alps and the three-loop run laps Thun's bridges back to the finish at the Lachenwiese, beside the transition, so the day is one venue and two long loops out.
IRONMAN's colour-to-bag scheme is the same across European races, so this part is settled. Blue, red and white are your transition and street bags; pack each for the discipline it powers. The optional orange and black personal-needs bags are covered below.
Thun runs a mandatory day-before bike check-in at Stadion Lachen on Saturday, 12:00–18:30, with the bike racked overnight — there's no race-morning bike check-in to fall back on. You drop the blue and red bags at the same time, and you collect your timing chip as you leave. The white and personal-needs bags go in on race morning instead.
The 2026 official guide is in. The times below are now confirmed for this edition — a few moved from last year.
The choreography barely moves year to year — transition opens at 05:00 and you can add to your blue and red bags until it closes at 06:30, the white bag goes in at the exit and the personal-needs bags at the entrance, then the rolling swim start at Lido Thun from 06:35. The order is what matters.
Five: blue for the bike, red for the run, white for street wear, plus optional orange and black personal-needs bags. Blue and red sit at the one rack at Stadion Lachen; the white bag is moved from the start to the Athlete Garden; the personal-needs bags are set out on course.
The blue bag is your bike / T1 bag — helmet, bike shoes, sunglasses, race belt and ride nutrition. It's racked with your bike at Stadion Lachen the day before, and your wetsuit goes back into it at T1.
Yes. Bike check-in is mandatory and day-before, Saturday 12:00–18:30 at Stadion Lachen, racked overnight. There is no race-morning bike check-in, and you collect your timing chip on the way out, so don't plan to bring the bike on race day.
They're optional personal-needs bags: orange is set out on the bike at km 95, black on the run at km 5, 19.3 and 33.6. You hand them in at the transition entrance on race morning. You won't get them back — anything left in them is discarded, so no valuables.
Pack the blue bag for cold, technical descents: arm warmers and light gloves for the two loops into the Bernese Alps. The high ground can be cool even when the lakeshore is warm, so dress for the descent, not the start — and respect the no-aero-bar and downhill sections flagged in the briefing.
This edition has raced — the structure above stays for reference. Add Thunand RackSide has a personal, deadline-aware plan ready the moment the next edition's guide is published.