In 2007 he competed in Grand Prix motorcycle racing's 125cc category for the Red Bull KTM team.

On Monday 24 March 2008 Krummenacher was injured when he crashed his mountain bike while training on a snow-covered downhill run.

Shortly afterward, he traveled to Jerez, Spain for the upcoming Spanish motorcycle Grand Prix where his injury was initially diagnosed as a bruised rib.

He was subsequently taken to a hospital in Jerez where it was discovered that he had lost more than 3 liters of blood and he immediately underwent life-saving surgery to remove his ruptured spleen.

After moving up to the Superbike category for the 2017 season[6] which he finished in 16th place, Krummenacher made his return to Supersport in 2018 with the Bardahl Evan Bros. WorldSSP Team[7] scoring three podium finishes, including a win in Thailand,[8] in his first 4 races of the season.