Rumors have been swirling that It’s well known that Scott Swisspower athlete Nino Schurter won this past weekend’s World Cup XC at Pietermaritzburg on a 650B-wheeled mountain bike, and now we’ve got confirmation on the frame.

Scott Sports USA’s marketing manager Adrian Montgomery confirmed to us that Schurter was racing aboard a carbon fiber prototype built around the 27.5″ wheel size.

“We’ve been testing alloy prototypes for the past few months,” Montgomery said. “Nino’s was the first carbon prototype. What you’re seeing is an experiment, we intentionally didn’t make a big deal out of it. We wanted to see what the press would say and gauge the public’s response.

“Scott Sports takes the stance of develop and test first. If it works, then we’ll see if it makes sense in the market. We don’t just create something and throw it under our athletes and tell them to win so we can sell it. In this case Nino wanted it.”

Of course, also in this case, it worked out pretty well for them, and Montgomery admitted they’re pretty stoked to get a World Cup win on their first outing. Click through to learn more…and see the rest of the cropped image above, it’s pretty wild!

The top picture was cropped from this one, provided by Scott Swisspower team’s photo gallery from the race. All photos by Armin Küstenbrück.

As for the nomenclature, “We’re sticking with the same measurement standard as 26″ and 29″, calling it 27.5″ (and not 650B),” he said. “It just makes sense rather than mixing measurements.”

And to explain testing the middle wheel size, Montgomery said Schurter, who is 5’8″, wasn’t able to produce the power he wanted on a 29er, but wanted better roll over than a 26″. He continued: “I can confirm that it was 27.5″ wheels. But what you’re seeing here is just us testing, I wouldn’t say it’s anything you’re going to see for 2013.”

Of course, there are plenty of high end parts on display for something that’s just an experiment, and we’ve already heard that many brands -bike and components- are working on 27.5″ / 650B frames and parts. On Schurter’s bike, you’re looking at a 27.5″ fork and carbon tubular wheels from DT Swiss and Dugast tubular tires.

We had to blow this one up quite a bit, hence the graininess, but it’s worth pointing out that tire clearance at the fork arch and near the seat tube are almost identical to the clearance shown on their 26″ Scale hardtail…part of the reason it took us a bit to confirm this was in fact a new wheel size.

The 2012 Scott Scale SL 26″ hardtail, from their website.

This last one is from SRAM’s PR bit about him winning on the new Grip Shift XX, but it shows how everything on the bike that would normal indicate wheel size was missing…and that his bike totally belongs on slamthatstem.com.

So what do you think? Does a World Cup win on a course with some obvious gnar help sell you on the middle child wheel size?