32" Wheels, 4,000m of Climbing, and Two Dominant Solos: The XCM World Championships Just Changed MTB Forever

Most World Championship victories leave a technical footnote. Andreas Seewald's win in the Dolomites on Saturday left an earthquake. The German crossed the Fiera di Primiero finish line in 4:33:47 aboard a prototype KTM Scarp Evo 4 equipped with Duke Lucky Jack SLS5 32-inch wheels — a wheel size that, until now, had never won a major world title. Meanwhile, Swiss rider Anna Weinbeer turned in one of the most commanding solo performances in XCM history, breaking the women's field so completely that she spent the final 70 kilometres of a 95km course entirely alone. Two riders, two different stories, one seismic day for mountain biking.

The 2026 UCI Mountain Bike Marathon World Championships were held in Primiero San Martino di Castrozza, Trentino — a setting as beautiful as it is brutal. Both elite races unfolded on an extended version of the established Mythos Primiero Dolomiti Marathon course, with around 4,000 metres of climbing packed into 95 kilometres. This is not a race for the faint of watts.

Weinbeer's Unstoppable Season Reaches Its Peak

Going in, Anna Weinbeer was the obvious favourite, and she did absolutely nothing to disappoint. The 31-year-old Swiss rider had won four of five rounds of the HERO UCI Cross-country Marathon World Cup in 2026, already locking up the series title before the Worlds even started. She had also claimed the European Continental Championship title in July, winning that race by more than four minutes. The only thing missing from her 2026 résumé was a rainbow jersey — and she fixed that decisively on Saturday.

Weinbeer broke clear of the field after the opening 25km and rode the remaining 70km entirely alone, finishing in 5:30:54. Italy's Claudia Peretti took silver in 5:34:47, with Switzerland's Mona Mitterwallner rounding out the podium in 5:39:13. The US pair of Melisa Rollins and Savilia Blunk rounded out the top five. Swiss Cycling had been calling 2026 a "fairytale season" for Weinbeer all year — Saturday was the final chapter. Last year she finished second at Worlds in Valais; this year, no one came close.

Seewald and the 32-Inch Revolution

The men's race had a different, drama-laden script. Pre-race favourite David Valero Serrano of Spain — leader of the HERO UCI XCM World Cup standings who had dominated the European Championships on home soil — suffered a flat tyre on the very first climb. Forced to fix it himself under marathon rules, he lost significant time and his chances were effectively over before the race had truly begun.

That misfortune reshuffled the front group entirely. Defending champion Keegan Swenson, Jordan Sarrou, Martin Fanger, and Andreas Seewald found themselves at the sharp end of a race now missing its clear pre-race pick. Seewald — a 35-year-old Canyon Northwave rider who had previously won this title at Elba in 2021 — proved the strongest, pulling clear to win in 4:33:47. Gioele De Cosmo (Italy) edged compatriot Jakob Dorigoni for silver by a single second, 4:36:59 to 4:37:00.

But the result almost takes a back seat to how Seewald won it. He raced the entire 95km on 32-inch wheels, making him the first rider ever to win a Mountain Bike World Championship on that wheel size. The 32" format sits between the established 29-inch standard and a theoretical 33" size; in recent seasons it has generated enormous industry buzz but precious little high-profile hardware. Seewald ran the Duke Lucky Jack SLS5 32" RC-1 Edition wheelset paired with what appeared to be a Fox 34 SL 32" fork — both prototype-level equipment. The result isn't just a personal triumph; it is the highest-profile validation the 32-inch movement has ever received.

What the 32" Data Actually Means

Wheel size in mountain biking has been a data-driven arms race since 29-inch wheels displaced 26-inch as the XC standard. The argument for 32" centres on a straightforward physics trade-off: a larger wheel rolls over obstacles more easily (better rollover coefficient) and maintains momentum through rough terrain, but adds rotational weight and can complicate handling in tight switchbacks. On a 95km Dolomites course that rewards rolling efficiency over sharp-corner agility, the advantages were clearly tilted toward the bigger wheel.

Seewald had finished second in the season opener at Costa Blanca on conventional equipment. His decision to gamble on prototype 32" wheels at the World Championships reflects confidence built from extensive testing — this was not a last-minute stunt. Earlier this season, Felix Stehli had won a stage of the Absa Cape Epic on 32" wheels, but a Worlds title is a categorically different level of proof. Expect every major wheel manufacturer to accelerate 32" development programmes before the 2027 season.

What This Means for Your Riding

You probably won't be ordering 32" wheels this week — availability is essentially zero outside prototype channels right now. But Seewald's victory is the clearest signal yet that the technology is coming, and coming fast. Here's how to think about it:

• If you ride marathon or gravel events on fast, rolling terrain, watch 32" development closely. The rollover advantages that won a World Championship on a 4,000m climbing course translate directly to the terrain where enthusiast marathon riders spend their time.
• If you race XCO or tight singletrack, the 29" standard remains dominant and is unlikely to change for short-course racing where low rotational weight and handling agility matter more.
• For equipment buyers right now, Weinbeer's dominance is the more immediately actionable story: she won by doing everything right at the training and preparation level, not by out-gearing the field. Four World Cup wins before Worlds isn't luck — it's consistent execution over a full season. Build your race form the same way.

The 2026 XCM World Championships will be remembered as the race where two riders turned up, rode away from everyone, and one of them did it on wheels that barely existed as a concept eighteen months ago. The Dolomites delivered the drama. Seewald and Weinbeer provided the dominance. And the 32-inch wheel size finally has its rainbow jersey.