In a small bowl, whisk together the chili sauce and the mayonnaise. Pull apart or slice the imitation crab into thin strips. Add crab meat to the bowl of spicy mayo and stir to coat.
Peel the cucumber and slice it into thin strips. Place one nori sheet on a bamboo sushi mat with the shiny side of the seaweed facing down and the lines running horizontally.
Carefully roll up the nori sheet, using the bamboo mat to press everything inward. Dip clean fingers in a bowl of water and wet the strip of nori at the top of the roll that does not have rice.