Cyclocross races take place in autumn and winter over short courses of 2.5-3.5 km featuring pavement, trails, grass, hills and obstacles requiring riders to carry their bicycles at times. Cyclocross bicycles are similar to road bikes but have slightly wider tires to handle multiple surfaces, and must be lightweight enough for competitors to carry over barriers. The document discusses cyclocross frame options with cantilever brakes or disc brakes.