ARC400

ARC400 – Unteruhldingen, Germany

• Date: 18 September 2026
• Location: Unteruhldingen Hafen, Germany
• Distances: 400 km
• Event Type: Self-supported Ultra-Cycling

The ARC400 is an unsupported ultra cycling event in Germany, a journey of approximately 400 kilometres circling the vast expanse of Lake Constance. Starting and finishing in the harbour town of Unteruhldingen, the ride is an exercise in self-reliance and personal route-planning. It is not a traditional race with a fixed course, but a challenge defined by seven checkpoints spread across four countries. The spirit is one of adventure, where the path between each point is entirely your own, guided by your chosen strategy and the quiet landscapes ahead.

This ultra cycling event in Germany unfolds across a varied and demanding landscape. While the route begins and ends by the lake, it steers clear of the flat shoreline, instead guiding riders into the hills and mountains that frame the water. The parcours is a mix of asphalt and gravel, with certain checkpoints intentionally placed on unpaved forest or farm tracks. With around 4,000 metres of elevation gain, the terrain requires thoughtful preparation and a versatile bike, whether a capable road machine with wide tyres or a fast gravel bike.

The format is purely self-supported. Riders are responsible for their own navigation, supplies, and accommodation choices between the start and finish. External assistance is not permitted, with the exception of commercially available services accessible to all participants. The organisers provide support only at the designated checkpoints, where riders will find food from Campo Verde, drinks, and a place to rest. This ethos puts the focus squarely on the individual experience, whether you ride through the night or choose to pause for sleep.

The event begins on Friday, September 18th, 2026, from Unteruhldingen. A key element of the challenge is that the final coordinates of the seven checkpoints are only revealed one week before the start. This ensures a level playing field for route planning. Timing is recorded via transponders and a traditional stamp pass at each checkpoint, with live results available. While there are solo categories for men and women under and over 40, the emphasis is on the personal journey rather than direct competition.

The route traces a wide arc around Lake Constance, dipping into Germany, Austria, Liechtenstein, and Switzerland. From the start in Oberschwaben, the course moves through the Allgäu region and into the Austrian Bregenzerwald. It continues south to Liechtenstein before turning north again through Switzerland and the Hegau region of Germany. This international loop offers a rich tapestry of scenery and surfaces, showcasing more of the region than a simple lakeside loop. There are many other other gravel events in Germany, but few offer this four-country perspective.

The experience concludes back in Unteruhldingen, with the finish line positioned directly beside the lake. Awaiting the finishers is a sense of accomplishment, along with a post-ride atmosphere featuring a DJ and a bonfire. It is a fitting end to a significant personal challenge. The ARC400 is about the rhythm of the ride, the choices made along the way, and the quiet satisfaction of completing a grand loop under one's own power. For full details and registration, please consult the official event website.