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.
Add ¾ cup of prepared sushi rice to the nori sheet and gently spread it until it covers about 80% of the nori, with an inch at the top uncovered. Rice layer should be no more than ¼ inch thick.
Spread ¼th of the crab salad across the middle of the rice layer on the nori sheet.
Place a few strips of cucumber on top of the crab.
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, pressing the dampened nori on the outside of the roll to seal it.
Place the roll with the seam side down on a sheet of plastic wrap and tightly cover the roll while keeping its shape. Set aside to rest for 10 minutes.
Repeat until all 4 sushi rolls have been prepared.
To serve, unwrap a roll and cut it into 8 slices. After you cut each slice, rotate the sushi roll to prevent smashing it down.
