Gallery: Riders preview Paris-Roubaix course

The pavé of Paris-Roubaix are the most challenging stretches of "road" the professional peloton will race over at any point in the season, and each of the 28 sectors has its own character. The steepness of the slope from crown to ditch, the unevenness of the stones, and the amount of grass growing in between each cobble all combine with the weather to create and ever changing canvas of agony for the riders.