The Rapperswil Bike Leg: 90 km Over Two Laps That Decide the Race

The Numbers, With a Caveat

The bike leg at IRONMAN 70.3 Switzerland in Rapperswil-Jona is 90 km over two laps of roughly 45 km, along the Obersee and through the green hills inland. Sources disagree on the elevation gain: the race info sheet lists around 900 m of climbing, while the more detailed source puts it at around 1,100 m. The difference doesn't change the big picture, but it does change your pacing: take the higher number as your conservative reference and check the official 2027 map before you race. This is not a pure time trialist's course: it's a demanding half on the bike, with fast sections along the lake and constant surges as soon as the road climbs inland.

"Witches' Hill" and the Character of the Lap

The climb known as "Witches' Hill" is the signature point of the course: it's described as steep and you tackle it twice, once per lap. Exact gradients aren't available in the sources consulted, so don't plan your watts to the gram on that section: go by feel and by zones. The rest of the lap alternates flat lakeside roads with punchy climbs and descents: you need the ability to change pace without burning your race in the first 45 km.

The Second Lap Is the Race

On a two-lap course, the classic mistake is riding the first lap "on adrenaline." Here it costs you dearly, because after the bike there's a half marathon with a staircase through the old town. The plan is simple: first lap at 72-75% of your FTP, climbs included, without chasing anyone who passes you on the punchy sections. On the second lap, it's your call: if the legs are responding, you can lift the intensity slightly over the last 20 km; if you're on the limit, you still have margin to save your run. Plenty of common-sense data backs this up: on rolling courses, the difference between a 1:40 run and a 2:00 run is almost always built on the bike, not on foot.

Descents and Rain: Plan B

The descents are described as technical, and in early June rain is common in Switzerland. Three concrete actions: practice at least one descent on wet tarmac in training, to understand your real braking limits; drop your tire pressure slightly if the weather looks iffy; carry a lightweight rain jacket in your pocket or leave it in your bags, depending on the day's rules. In the wet, brake before the corner and in a straight line: seconds lost on a descent can be recovered, a crash can't.

Gearing and Equipment

With no official gradients in the sources, the safe choice for an age-grouper on a course with steep kickers is a compact 50/34 with an 11-32 or 11-34 cassette: it lets you climb "Witches' Hill" at a humane cadence twice, without shredding the muscles you'll need on the run. The TT bike is still the right choice for the long lakeside stretches, but make sure you're comfortable descending on the extensions.

What to Do Between Now and Race Day

• Simulate the course: two consecutive laps on a local loop with similar elevation gain (900-1,100 m over 90 km), at 72-75% FTP, followed by a 20-30 minute run.
• Add short repeats on steep climbs with a surge over the top: it's the move this course demands most often.
• Test your bike nutrition (60-80 g/h of carbs, adequate sodium) on these exact rides, not on race day.
• Check the official map when the 2027 version drops: the current info sheets mark sections as indicative.

If you come out of T2 having stuck to the plan, the castle staircase will feel a lot less scary.