You avoid traffic by taking unpaved roads where your comfortable wide tires may sometimes briefly lose contact with the ground when riding over drops up to 15 cm high. The higher system weight of the wheels gives your gravel bike the reliability you need for lengthy bikepacking trips. All carbon and aluminum models in the gravel category are available in standard wheel size 700C and the smaller 650B size. Gravel bikes in this category need disc brake systems, given the stronger forces triggered by the various stresses you encounter on the terrain.