Aaron Gwin quotes:

Ever since I was a little kid, when I was racing motocross and stuff, it's been a dream to ride for Red Bull someday.

With a larger wheel, you have more contact with the ground, so you have better traction whether you're braking or cornering or any of that stuff. Also, with bigger wheels, once you get them up to speed, they roll faster.

If you're rolling over rocks and stuff and you have a bigger wheel, it's going to stay out of the holes - rough sections become smoother.