When you're mountain biking in extreme conditions, you want tires that are light enough for nimble handling, sticky enough to grip rocky and rooty trails, and tough enough to last. Most can't do it all: Beefy tires have bite, but they're sluggish; light tires are nimble, but they wear out quickly or puncture.

Vittoria's new Mezcal and Morsa tires eliminate that trade-off once and for all. They are infinitely tough and elegantly maneuverable.

Here's why. Graphene, in its most basic form, is a sheet of pure carbon just a single atom thick. It is half the density of aluminum, which means it's light and extremely elastic.

Vittoria uses graphene that is two to eight atoms thick—nearly invisible. By adding it to mountain-bike tires, Vittoria achieves the dream combo of characteristics—light, sticky, and tough—that rubber can't on its own. In fact, adding graphene to rubber creates a tire that changes depending on how you ride. When riding on a straightaway, the tire stays relatively hard. When braking or cornering, it softens.