Belgian Kenny Belaey is a multiple trials world champion in the 26-inch category. Before he set out to ride a highline in the French Alps, he had never stood on a slackline, even without a bike. When walking on the swinging webbing, the golden rule is not to look down, but only at the end of the line or, even better, above it. But that doesn't work when you're trying to hold a mountain bike tire on the five-centimetre-wide webbing. Even the slightest deviation from the center causes the belt to lean sideways and the tire to slip off. Belaey had no choice but to constantly stare at his front wheel, the highline and 112 meters below him.